Physiol Rev
83: 1113–1151, 2003; 10.1152/physrev.00009.2003.
Preconditioning the Myocardium:
From Cellular Physiology to Clinical Cardiology
DEREK M. YELLON AND JAMES M. DOWNEY
The Hatter Institute for Cardiovascular Studies, University College London Hospital and Medical School,
London, United Kingdom; and Department of Physiology, University of South Alabama
College of Medicine, Mobile, Alabama
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
I. Introduction: Myocardial Preconditioning
II. Natural History of Classical Ischemic Preconditioning
A. Triggers versus mediators
B. Duration of effect
C. End points of preconditioning studies
D. The preconditioning stimulus
E. Preconditioning in other organs
F. Remote preconditioning
III. Cellular Mechanisms of Classical Preconditioning
A. Trigger mechanisms
B. Mediators: signal transduction pathways
C. KATP channels
D. Possible end-effectors
E. Summary of classic preconditioning
IV. Natural History of the Second Window of Protection
A. What is SWOP?
B. Triggers
C. Mediators: signal transduction pathways
D. Possible end-effectors
V. Preconditioning Human Myocardium
A. In vitro studies
B. In vivo studies
C. Therapeutic implications
D. Summary
VI. Conclusion and Perspectives
1114
1115
1115
1115
1115
1117
1117
1118
1118
1118
1119
1121
1125
1127
1127
1127
1128
1130
1130
1133
1133
1134
1138
1140
1140
Yellon, Derek M., and James M. Downey. Preconditioning the Myocardium: From Cellular Physiology to Clinical
Cardiology. Physiol Rev 83: 1113–1151, 2003; 10.1152/physrev.00009.2003.—The phenomenon of ischemic preconditioning, in which a period of sublethal ischemia can profoundly protect the cell from infarction during a subsequent
ischemic insult, has been responsible for an enormous amount of research over the last 15 years. Ischemic
preconditioning is associated with two forms of protection: a classical form lasting ⬃2 h after the preconditioning
ischemia followed a day later by a second window of protection lasting ⬃3 days. Both types of preconditioning share
similarities in that the preconditioning ischemia provokes the release of several autacoids that trigger protection by
occupying cell surface receptors. Receptor occupancy activates complex signaling cascades which during the lethal
ischemia converge on one or more end-effectors to mediate the protection. The end-effectors so far have eluded
identification, although a number have been proposed. A range of different pharmacological agents that activate the
signaling cascades at the various levels can mimic ischemic preconditioning leading to the hope that specific
therapeutic agents can be designed to exploit the profound protection seen with ischemic preconditioning. This
review examines, in detail, the complex mechanisms associated with both forms of preconditioning as well as
discusses the possibility to exploit this phenomenon in the clinical setting. As our understanding of the mechanisms
associated with preconditioning are unravelled, we believe we can look forward to the development of new
therapeutic agents with novel mechanisms of action that can supplement current treatment options for patients
threatened with acute myocardial infarction.
www.prv.org
0031-9333/03 $15.00 Copyright © 2003 the American Physiological Society
1113
1114
DEREK M. YELLON AND JAMES M. DOWNEY
I. INTRODUCTION: MYOCARDIAL
PRECONDITIONING
Physiol Rev • VOL
FIG. 1. Original infarct size data from Murry et al. (239), who were
the first to describe ischemic preconditioning. Open circles represent
infarct sizes in individual dogs while solid circles depict group
means ⫾ SE. [Modified from Murry et al. (239).]
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
Acute coronary occlusion is the leading cause of
morbidity and mortality in the Western world and according to the World Health Organization will be the major
cause of death in the world as a whole by the year 2020
(238). Although the management of this epidemic will
center on the development of effective primary prevention programs, the impact of these strategies may be
limited, particularly in the developing countries. There
is an urgent need for effective forms of secondary
prevention and, in particular, treatments which will
limit the extent of an evolving myocardial infarction
(MI) during the acute phase of coronary occlusion. The
death of myocardium represents a catastrophic event
as dead myocytes are not replaced by division of surviving myocytes. Preserving the viability of ischemic
myocardium therefore has been recognized as a major
therapeutic target.
In the early 1970s, attention was first focused on this
problem in the animal laboratory. Maroko et al. (215)
proposed that a variety of interventions at the time of
coronary occlusion could reduce the size of the resulting
infarct in the open-chest dog. At that time the models for
evaluating infarct size were very crude, and none of the
original interventions proposed, such as beta blockers
(215), glucose-insulin-potassium (217), or hyaluronidase
(216), ever proved to be effective. Nevertheless, those
early studies initiated the search for interventions that
could limit infarct size in the clinical setting. Jennings and
Reimer (159) demonstrated that reperfusion was essential
to protecting the ischemic myocardium, and soon thereafter, the introduction of thrombolytic therapies became
routinely available. While reperfusion therapy clearly was
reducing infarct size, as demonstrated by the extensive
NIH-sponsored Thrombin Inhibition in Myocardial Ischemia (TIMI) trials, it also became clear that reperfusion
had not eliminated infarction. Unfortunately, myocardium
begins to die in minutes; however, dissolution of the
offending thrombus and subsequent reperfusion usually
requires hours to accomplish so there was still a need for
an infarct sparing intervention. The quest was hampered
by the fact that scientists did not (and still do not) know
what the lethal event is in the ischemic heart. A number of
candidates such as anti-inflammatory agents and free radical scavengers were examined through the early 1980s
but all with mixed results (285).
It is interesting to note that until 1986 it was not even
known whether therapeutic infarct size limitation was
possible. While a rather large number of drugs were
touted to limit infarct size in the setting of ischemia/
reperfusion, none of these studies could be consistently
reproduced in the animal laboratories. Much of the confusion at the time derived from the fact that the amount of
infarct size limitation claimed by any of these studies was
modest (10 –20%) and that the animal models were still
quite poor. Many of the baseline variables affecting infarct
size such as temperature (65), risk zone size (409), and
collateral flow (284) were poorly appreciated at that time
and were seldom adequately controlled. In retrospect,
most of those studies, including some published by the
authors of this review, were probably simply false positives.
Perhaps the single greatest advance in our understanding of the cell survival machinery was the discovery
in 1986 by Murry et al. (239) of an intrinsic mechanism of
profound protection, which they termed ischemic preconditioning (see Fig. 1). In this seminal paper, they showed
that four cycles of 5 min of ischemia with intermittent
reperfusion were shown to limit infarct size by 75%, an
amount of protection heretofore unheard of. More importantly in the subsequent years that followed, the antiinfarct effect of preconditioning could be reproduced by
all who tried it (for a review of the early studies, see Ref.
192). For the first time it was shown that infarct size
limitation was theoretically possible. Indeed, so powerful
was the observed protection that this phenomenon has
been recognized as “the strongest form of in vivo protection against myocardial ischemic injury other than early
reperfusion” (175). It appeared therefore that all that
remained was to investigate the mechanism associated
with the profound protection in order for pharmacological mimetics to be developed that could ultimately be
used in the clinical setting. At the time of writing this
review there have been in excess of 2,000 papers published on this subject.
MYOCARDIAL PRECONDITIONING
II. NATURAL HISTORY OF CLASSICAL
ISCHEMIC PRECONDITIONING
A. Triggers Versus Mediators
B. Duration of Effect
Ischemic preconditioning has been demonstrated in
all animal species studied to date including the chicken
(202), dog (239), mouse (322), pig (301), rabbit (72), rat
(201), and sheep (53). All of our knowledge about preconditioning is empirically derived from studies in a variety of
species including humans. Although it is assumed that
preconditioning’s mechanism is common to all species,
there have been obvious mechanistic discrepancies among
the various reports, and some of them could well be related
to species differences. Some of these differences are obvious such as the role of xanthine oxidase as discussed below,
but the reader should note the species being studied and
consider the possibility that any reported mechanism may
be species specific and more importantly may not be relevant to human heart. In terms of the extent of the protection
observed, it must be noted that preconditioning’s protection
is lost when the ischemic insult was extended to 3 h, indicating that reperfusion after the lethal ischemic insult is an
absolute requirement (239).
These observations indicate that ischemic preconditioning delays rather than prevents cell death. Most animal studies to date would suggest that preconditioning
acts as if it had reduced the duration of the ischemic insult
by ⬃20 –30 min. In primate myocardium, which for unknown reasons infarcts much more slowly, that benefit may
be much longer (309). Murry and colleagues also found that
the protection seen with preconditioning was independent
Physiol Rev • VOL
of collateral flow indicating that the ability of the heart to
withstand ischemia had been directly modified. The cardioprotection described by Murry et al. (239) has become
known as “classic” or “early” ischemic preconditioning.
The preconditioned state is very transient following a
preconditioning protocol and lasts for only 1–2 h in anesthetized animals (240, 287, 363) and is lost somewhere
between 2 and 4 h in conscious rabbits (52). How the
heart remembers that it is preconditioned is another mystery that has resisted laboratory investigation. Thornton
et al. (340) reported that protein synthesis inhibition with
either actinomycin D or cycloheximide did not block
preconditioning’s protection seemingly eliminating gene
expression as a possible mechanism of the memory. Matsuyama et al. (219) also obtained the same result with
actinomycin D; however, using a much higher concentration of cycloheximide, they were able to block protection
from ischemic preconditioning. They suggested that because cycloheximide only blocks translation of message
that preconditioning causes the translation of a prexisting
mRNA coding for a protective protein. Since the initial study
by Thornton et al. directly confirmed protein synthesis inhibition, the most likely explanation is that the latter study
may have suffered from a nonspecific effect due to the high
cycloheximide concentration. Also, because the preconditioned state can be achieved within 10 min, it is unlikely that
any protein could be expressed in such a short time period.
The memory information is probably carried as a reversible
posttranslational modification of some preexisting protein
(such as a phosphorylation or translocation), but the site of
that modification is unknown.
Although the initial window of protection is quite
transient, a delayed form of the protection reappears
within 24 h of the preconditioning stimulus, which has
been referred to as the second window of protection
(SWOP) (213). The less robust, although more prolonged,
SWOP occurs between 12 and 72 h after a preconditioning
stimulus (26) (see Fig. 2). Both classical and SWOP preconditioning share some similarities. In both cases the preconditioning ischemia provokes the release of a number of
trigger substances that interact with cell surface receptors,
thereby initiating a signaling cascade of events. These triggers appear to be the same in both forms of preconditioning.
The time course within which the SWOP confers protection
allows for the possibility of new protein synthesis, posttranslational protein modification, and a change in the compartmentalisation of existing proteins. The mechanisms of
SWOP will be discussed in greater detail in section IVB.
C. End Points of Preconditioning Studies
1. Infarct size
The original end point used for the assessment of
protection from classical preconditioning was infarct size
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
When considering preconditioning it is useful to
think in terms of triggers, mediators, memory, and endeffectors. The preconditioning ischemia triggers a change
in the physiology of the heart, rendering it very resistant
to infarction. We know that a series of signal transduction
pathways carry the signal for protection, and those presumably terminate on one or more end-effectors. The
end-effectors actually cause the protection during the
lethal ischemic insult (index ischemia) and/or the subsequent reperfusion period. Somewhere in the signal transduction pathways between the trigger signal and the endeffector is a memory element that is set by the preconditioning protocol and keeps the heart in a preconditioned
state. All steps distal to the memory step including the
end-effector can be classified as mediators since they
exert their activity only after the index ischemia has
begun, and those proximal to the memory element can be
considered triggers because they exert their effect only
prior to the index ischemia.
1115
1116
DEREK M. YELLON AND JAMES M. DOWNEY
(239) expressed as a percentage of the risk zone. Many
animals have coronary collateral vessels that provide a
low level of irrigation during ischemia. Collateral flow
opposes infarction causing an inverse relationship between collateral flow and infarct size. In animals with
preformed collaterals such as the dog, collateral flow
must be taken into account (284). Infarct size is commonly assessed by staining viable tissue with tetrazolium
salts. The tetrazolium salts react with NADH and dehydrogenase enzymes staining the tissue (174). Dead cells
lose enzyme and cofactor due to membrane failure and
thus do not stain. To sufficiently wash out these components 2–3 h of reperfusion are required. The gold standard
for infarct size, however, is histological examination of
tissue slices after 3 or more days of reperfusion as was
used by Murry et al. in their original description of preconditioning (239). Under these conditions, classical preconditioning has limited infarct size in every species
tested.
2. Stunning
Whether preconditioning attenuates stunning has not
been totally resolved. Stunning refers to a loss of contractility that immediately follows a sublethal ischemic insult.
Unlike the infarcted heart, the stunned myocardium recovers fully in a day or two. For a review on the stunned
myocardium, see Reference 48. In most species an ischemic insult of 15 min or less stuns the heart but does not
cause infarction. Ovize et al. (258) studied the dog heart
which, unlike the human heart, is rich in xanthine oxidase. They preconditioned hearts with either a 2.5- or a
5-min period of ischemia before the 15-min index ischemia. Although recovery of function in the preconditioned
hearts was twice that in the control group, the authors
Physiol Rev • VOL
3. Recovery of mechanical function
Postischemic recovery of contractile function is a
commonly used end point for ischemic preconditioning in
the isolated rat heart (22, 61, 380). However, recovery of
mechanical function after an ischemic insult is influenced
by both a combination of the number of surviving myocytes and the degree to which they have been stunned. It
is well appreciated that the effect of preconditioning on
recovery of function is much less pronounced in species
other than the rat (318).
Gelpi et al. (117) proposed that the antistunning effect in the rat might be the result of altered adenosine
metabolism in the rat’s heart. Free radicals have been
shown to strongly contribute to stunning of reperfused
myocardium (48), and rat hearts are rich in xanthine
oxidase (97). Adenosine released during ischemia is converted to inosine and then hypoxanthine. Upon reperfusion, hypoxanthine is oxidized by xanthine oxidase producing injurious free radicals that stun the heart (51, 62,
64). Preconditioning the heart with a brief period of ischemia followed by reperfusion will greatly attenuate the
amount of adenosine released during the next ischemic
episode (364), which in turn would reduce the amount of
xanthine oxidase-mediated free radical production and
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
FIG. 2. Diagrammatic representation of the temporal nature of the
two windows of preconditioning. (Modified from Sumeray MS and Yellon DM. Ischaemic preconditioning. In: Ischaemia-Reperfusion Injury,
edited by Grace PA and Mathie RT. London: Blackwell, 1999, chapt. 27,
p. 328 –343.)
concluded that prior preconditioning did not influence the
degree of recovery. This conclusion was based on an
analysis in which postischemic function was related to
the level of collateral blood flow in each heart. The improved recovery in preconditioned hearts was attributed
to better perfusion during ischemia rather than preconditioning. Examination of those data reveals, however, that
there was no significant correlation between collateral
flow and recovery of function in two of the three experimental groups, indicating that the assumption regarding
the influence of collateral flow could not be supported.
Hence, the authors’ conclusion may not be firm, and
preconditioning rather than higher collateral flow may
well have protected against stunning in that study. Jenkins et al. (158) noted that preconditioning did not affect
stunning in rabbits, a species whose hearts are deficient in
xanthine oxidase. Landymore et al. (190) noted that preconditioning prevented stunning after cardiac transplantation in sheep, but it is not known whether sheep hearts
contain xanthine oxidase. Finally, Sekili et al. (307) noted
that when dog hearts were pharmacologically preconditioned with a transient infusion of adenosine that no
protection against stunning could be observed. The pharmacological preconditioning would not have attenuated
adenosine release on a subsequent coronary occlusion
(121). If classical preconditioning has an antistunning
effect it must be small. That is surprising because SWOP
reportedly has a robust antistunning effect in both rabbits
(47) and pigs (334).
MYOCARDIAL PRECONDITIONING
4. Arrhythmias
Ischemic preconditioning has also been reported to
alter the incidence of ischemia and reperfusion-induced
arrhythmias in dogs (367) and rats (310). The experience
with most investigators studying other species has been
that preconditioning either has little effect on arrhythmias
or actually exacerbates it (256). Free radicals are also
known to lead to the genesis of arrhythmias in the heart
(187), and it is likely that antiarrhythmic effect of preconditioning in dog and rat may again be related to attenuated
purine release, although that hypothesis has not been
directly tested.
5. Electrocardiographic changes
It must be emphasized that infarct size testing is the
only established end point for preconditioning at this
time, and extrapolated findings from recovery of contractile function or arrhythmias need to be interpreted with
caution. Unfortunately, studies in humans have forced
investigators to examine surrogate end points such as
electrocardiographic changes. Cribier et al. (80) noted
that in patients undergoing coronary angioplasty that the
S-T segment voltage was much lower during the second
coronary occlusion than on the first. He concluded that
this reflected the protection of preconditioning from the
first balloon inflation. A number of drugs were subsequently tested in this setting to see if they could mimic or
block preconditioning in humans (for a review, see Ref.
344). One criticism of the technique was that the reduced
S-T segment voltage might only have reflected opening of
Physiol Rev • VOL
collateral vessels between the inflations. Shattock et al.
(308) disproved that hypothesis by showing that the same
response could be seen in pig heart, which is collateral
deficient. It was later shown that the S-T segment changes
were influenced by surface ATP-sensitive potassium (KATP)
channels while protection from preconditioning was influenced by those in the mitochondria (41). It would appear
that preconditioning opens both populations of channels
while only the mitochondrial population acts to protect (see
below). Thus S-T segment changes may not be a reliable end
point for preconditioning studies either.
D. The Preconditioning Stimulus
Ischemic preconditioning requires a brief period of
ischemia followed by reperfusion to trigger the response.
The minimum period of reperfusion required giving protection after the preconditioning ischemia lies between
30 s and 1 min (5). Preconditioning was originally reported to be an “all or none” phenomenon. Li et al. (200)
compared 1, 6, and 12 cycles of 5-min coronary occlusions
in the dog and found no differences in the protection.
Another report (363) found no differences between one
and two 5-min cycles of preconditioning in the rabbit. A
similar observation was made in ex vivo human cardiac
tissue (236). On the other hand, studies using in vivo rat
(24a) or pig (304) models found that the resulting infarct
size varied with the strength of the preconditioning stimulus, suggesting a graded response. Off-on systems are
rare in nature, so more than likely preconditioning is
merely following a very steep dose-response curve. Once a
maximal response is achieved, further stimulation has no
additional effect, giving the impression of an all or none
system. Many studies take advantage of this very steep
dose-response relationship. A single 2-min coronary occlusion will not precondition the rabbit as it is below threshold
(363). However, in the presence of an intervention that
potentiates the triggers of preconditioning, such as angiotensin-converting enzyme (ACE) inhibitors which augment
interstitial bradykinin levels (155, 227) or agents that augment adenosine such as acadasine (52), preconditioning will
occur.
E. Preconditioning in Other Organs
Preconditioning was first described in the heart but
since then it has been seen in various forms in a variety of
organs. Classical preconditioning is seen in skeletal muscle (262), and its mechanism seems to be virtually identical to that seen in the heart directly protecting the
parenchymal cells (261). Classical preconditioning has
also been described in the gut (152) and in the kidney
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
thus stunning. Indeed, Gelpi et al. (117) found that the
xanthine oxidase inhibitor allopurinol improved postischemic function and greatly attenuated the improvement
from preconditioning in the rat model.
In rabbit hearts, which do not contain xanthine oxidase, preconditioning had no effect on postischemic function. To further complicate the situation, the mechanism
by which preconditioning attenuates purine release
seems to be unrelated to that used by the anti-infarct
effect (121) so that extrapolation of data from the rat
recovery of function model to preconditioning in humans
may be very misleading.
The overall aim of myocardial salvage is to improve
ventricular function. Oddly enough few studies have
tested whether preconditioning really does yield a stronger heart in the animal laboratory. Cohen et al. (76)
measured ventricular wall motion in conscious rabbits
subjected to regional ischemia/reperfusion. Not only did
preconditioning reduce infarct size, but it also improved
wall motion in the ischemic zone. It took at least a day for
stunning to subside however before the benefit could be
appreciated.
1117
1118
DEREK M. YELLON AND JAMES M. DOWNEY
(49). In the intestine, the microcirculation is the primary
target for ischemic injury while in the kidney it is the
proximal tubular cells. Yet the result is the same in all
three tissues, a rapid protection against cell death during
ischemia. In the brain (171), preconditioning is only protective in a second window-type setting a day after the preconditioning stimulus. Thus it would appear that preconditioning represents a generalized adaptation to protect a wide
variety of cells against stressful stimuli such as ischemia.
F. Remote Preconditioning
A. Trigger Mechanisms
In 1991 Downey and colleagues (206) found that the
adenosine A1 receptor acts to trigger ischemic preconditioning’s protection in the rabbit heart, revealing that
ischemic preconditioning is receptor mediated. Blockers
of the A1 receptor eliminated preconditioning’s protection
while transient exposure to an A1 agonist would confer
the protection. Shortly thereafter, Banerjee et al. (22)
reported a similar situation with norepinephrine through
the ␣-receptors in the rat heart. We now know that any
Gi-coupled receptor can trigger the preconditioned state,
and in fact, multiple receptors work in parallel to provide
redundancy to the preconditioning stimulus. During a
brief ischemic period, the heart appears to release adenosine, bradykinin, norepinephrine, and opioids. Population of their respective receptors then triggers the preconditioned state through activation of Gi protein. As a result,
blockade of the bradykinin receptor in the rabbit blocks
protection from a single cycle of preconditioning but not
from multiple cycles (122). Thus blockade of a single
receptor type acts only to raise the ischemic threshold
required to trigger protection rather than completely
block it (see Fig. 3). The cardiac myocytes express other
Gi receptors such as the angiotensin AT1, the endothelin
ET1, and the muscarinic receptors that can also trigger a
preconditioned state but do not seem to participate in
ischemic preconditioning simply because agonists to
those receptors are not produced in the ischemic myocar-
FIG. 3. An example of how multiple receptors act in
parallel in ischemic preconditioning. In the first panel, 5
min of ischemia reaches the threshold for protection, but
in the second panel, 3 min of ischemia does not. In the
third panel, blocking the bradykinin B2 receptor with
HOE 140 causes a 5-min ischemic period to become
nonprotective because it can no longer reach the threshold. Conversely, augmenting bradykinin’s contribution
with an angiotensin converting enzyme (ACE) inhibitor,
which prevents bradykinin breakdown, allows 3 min of
ischemia to reach a protective threshold. [Modified from
Goto et al. (122).]
Physiol Rev • VOL
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
One form of preconditioning that is poorly understood is remote preconditioning. In 1993 Przyklenk et al.
(278) reported that preconditioning one region of the dog
heart caused protection in a remote region. They hypothesized that a circulating humor or perhaps a neural reflex
triggered protection in the remote region. Similarly mesenteric artery occlusion was also seen to result in protection of the rat heart, further supporting the hypothesis
(368), and it was subsequently found that blockade of
opioid receptors in the rat blocked that response (266),
suggesting either a circulating endorphin or neural link.
Nakano et al. (246) tried to duplicate the effect in a rabbit
model where a region of the heart was preconditioned in
situ and then the heart was removed and exposed to
global ischemia. The amount of infarction was measured
in both the preconditioned and the nonpreconditioned
regions, but no differences were seen. It was concluded
that preconditioning one region of the heart does not
necessarily precondition the remote regions in all species.
III. CELLULAR MECHANISMS OF
CLASSICAL PRECONDITIONING
MYOCARDIAL PRECONDITIONING
Physiol Rev • VOL
stream targets for NO remain intact and as such may be
pivotal in mediating the protection.
B. Mediators: Signal Transduction Pathways
1. PKC
The role of PKC in preconditioning was codiscovered
by Mitchell et al. (228) and Ytrehus et al. (408) in 1994. It
can be shown that blockade of PKC eliminates the protection from a preconditioned heart but has no effect on
a nonpreconditioned heart. Similarly, activation of PKC
by phorbol esters will put the heart into a preconditioned
state. PKC is a serine/threonine kinase that is activated by
lipid cofactors derived from breakdown of membrane
lipids by phospholipase C. There are multiple isoforms of
PKC in the heart, each having a similar substrate specificity. They can be broken down into the classical isoforms ␣, ␤, and ␥, which are dependent on both the lipid
cofactor diacylglycerol (DAG) and calcium. The novel
isoforms, ␦, ␩, and ⑀, are calcium independent needing
only DAG. Finally, the atypical isoform ␨ requires neither
DAG nor calcium. The PKC isoforms are thought to
achieve specificity by their peculiar physical translocation
to docking sites. Mochly-Rosen and colleagues (161) discovered that each isoform will dock on a unique binding
protein called a receptor for activated C kinase (RACK)
when activated. These RACKS are strategically located
only on certain organelles within the cell to bring the PKC
isoform in proximity to a specific substrate protein. Binding to the RACK completes the activation and causes the
isoform to phosphorylate any nearby substrate. It is
thought that only certain isoforms participate in preconditioning. The ⑀ (125, 203, 274), the ␦ (412), and the ␣
(374) isoforms of PKC have all been proposed to be
responsible for preconditioning’s protection. The intracellular targets of PKC have not been established.
One of the great mysteries of preconditioning is its
memory. Transient activation of the Gi-coupled receptors
puts the heart into a preconditioned state lasting ⬃1 h.
Receptor occupation is a trigger of the preconditioned
state, and thus the critical time for receptor occupation is
during the preconditioning ischemia before the index
ischemia (204). This is in contrast to administration of a
PKC blocker. If staurosporine, a potent PKC blocker, is
given with the same schedule, then protection persists. It
would be logical that PKC would phosphorylate substrate
during preconditioning and then as long as the substrate
remained phosphorylated the heart would be protected.
Waning of protection would result from dephosphorylation by phosphatases. Unfortunately, the facts do not fit
the theory. The kinase activity of PKC can be completely
blocked with staurosporine during preconditioning, and
the heart still enters a preconditioned state (398). Only if
the staurosporine is present during the 30-min index isch-
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
dium. For a detailed review of this receptor interplay, see
Reference 71.
Free radicals also act as trigger mechanisms to preconditioning. Treatment with a free radical scavenger can
raise the threshold of preconditioning, and a free radical
generator can trigger a preconditioned state (17, 354). It is
thought that the free radicals act to directly activate protective kinases (120, 369). In species whose hearts are
rich in xanthine oxidase, the free radicals may derive
directly from xanthine oxidase’s action on purine catabolism. This conceivably could lead to a nonreceptor-mediated triggering of protection. In other species, such as
the rabbit heart, the free radicals seem to have a much
more complex origin, as will be discussed later in this
review.
Several other non-receptor-triggered forms of preconditioning have been described. Ashraf’s group (230)
has found that a short period of elevated Ca2⫹ in the
coronary perfusate will put the isolated rat heart into a
protected state that appears to be the same as that from
ischemic preconditioning as it is protein kinase C (PKC)
dependent (see sect. IIIB1). Furthermore, they found that
the calcium channel blocker verapamil could block not
only Ca2⫹-induced preconditioning in the rat heart but
ischemic preconditioning as well (229). A similar observation was made in an in situ dog model where intracoronary calcium chloride triggered protection and ischemic
preconditioning could be blocked with a sodium/calcium
exchanger blocker (279).
A transient period of hyperthermia has also seemed
to be cardioprotective with both a transient early phase
and a prolonged late phase (395). Whether the early phase
uses the preconditioning mechanism is unknown. Stretch
of the myocardial fibers is reported to precondition the
dog heart (257), and the protection could be blocked by
gadolinium, a blocker of stretch-activated channels. Transient exposure to ethanol can trigger the preconditioned
state, but interestingly, if it continues to be present during
the index ischemia, it will block its own protection (185).
Other forms of preconditioning such as pacing (183, 263)
and hypoxia (372) likely induce their protection through
release of receptor ligands due to the negative energy
balance.
Although nitric oxide (NO) has been linked to the
trigger and end-effector phases of delayed preconditioning (see later), evidence for its role in early preconditioning is limited if not controversial (210, 247, 277, 379, 384).
It appears that in early preconditioning, NO may lower the
threshold for the protection observed, even though in
itself it may not be a direct trigger of early preconditioning (36). Importantly, because exogenous (not endogenous) NO has been shown to trigger preconditioning both
in rabbits (247) as well as in the endothelial NO synthase
(eNOS) knock-out mouse (36), it appears as if the down-
1119
1120
DEREK M. YELLON AND JAMES M. DOWNEY
2. Tyrosine kinase and the mitogen-activated
protein kinases
Other kinases have been identified. Using genistein, a
broad spectrum tyrosine kinase inhibitor, Maulik et al.
(221) found that it could block protection from ischemic
preconditioning and proposed that at least one tyrosine
kinase is in the overall pathway. Baines et al. (20) provided evidence that a tyrosine kinase was downstream of
PKC; however, several other studies suggest that it (or
another one) may be in parallel with PKC in both pig (358)
and rat (111). The dynamics of the parallel arrangement
are interesting. When a mild preconditioning stimulus
such as a single 5-min coronary occlusion is given, either
a PKC or a tyrosine kinase blocker on its own will block
protection, suggesting that both pathways must be activated to achieve threshold for protection. When a more
robust stimulus is used, however, then blocking either
pathway alone will not block protection, and both inhibitors must be present. This suggests that either pathway
can be protective on its own if stimulated enough (336).
Physiol Rev • VOL
Maulik et al. (221) proposed that the tyrosine kinase
in question was the 38-kDa stress-activated mitogen-activated protein kinase (MAPK) (p38 MAPK). What followed
has to be one of the most confusing chapters in the
ischemic preconditioning stories. Each subfamily of the
MAPK family, the 42/44-kDa extracellular receptor kinase
(ERK), the 46/54-kDa c-jun kinase (JNK), and the 38-kDa
p38 MAPK, has been suggested to play a role in the
cardioprotection achieved by ischemic preconditioning
(for review, see Refs. 226, 270). All of the MAPKs are
activated by dual phosphorylation of a serine and a threonine by a MAPK kinase. The MAPK kinase is a tyrosine
kinase and at least the ones targeting p38 MAPK can be
blocked by genistein (244).
In isolated rabbit hearts, ERK1 activity reportedly
increases only in ischemically preconditioned myocardium (170), but no difference in ERK1 and ERK2 phosphorylation between nonpreconditioned and preconditioned myocardium is detectable in pigs in vivo (33). Like
p38 MAPK (see below), ERK can activate MAPKAP kinase
2 ␣ and ␤, leading to phosphorylation of the small heat
shock protein, hsp27 (300).
A causal role of ERK activation in the cardioprotection achieved by ischemic preconditioning is controversial. While PD 98059, an inhibitor of ERK, fails to block
the infarct size reduction seen after ischemic preconditioning in isolated rabbit and rat (233) hearts (170), its
intramyocardial infusion appeared to abolish ischemic
preconditioning’s protection in pigs in vivo (321). It is of
interest that ERK1 forms a signaling complex with PKC-⑀
in the heart along with other MAPK kinases (21). Thus
translocations of MAPKs may be involved in the signaling
in addition to their phosphorylation.
Both JNK46 and JNK54 are present in the heart (67)
and are strongly activated during reperfusion after ischemia. Their activation/phosphorylation during ischemia
has been suggested by some studies (33), but in another,
a reduction in JNK phosphorylation during ischemia was
reported (244). JNK46 activation during no-flow ischemia
is most likely mediated by PKC, since activation of JNK46
is completely blocked by chelerythrine, a PKC inhibitor
(273). Anisomycin, an activator of both JNK and p38
MAPK, reduces infarct size in rabbits (18) and pigs (23). In
isolated rat hearts, blockade of JNK46 with curcumin
blocks the infarct size reduction of ischemic preconditioning to a similar extent as blockade of p38 MAPK using
SB203580 (294).
Most attention has focused on the p38 MAPK cascade. At least five isoforms of p38 MAPK have been
identified, although only p38 ␣- and ␤-MAPK are expressed to any degree within the heart (298). Different
isoforms of p38 MAPK appear to mediate different biological functions (for review, see Ref. 226). In neonatal rat
cardiomyocytes, p38 ␣-MAPK mediates apoptosis,
whereas p38 ␤-MAPK is antiapoptotic (375).
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
emia is protection aborted. Thus PKC is a mediator rather
than a trigger of protection, and the memory step must
reside upstream of PKC activity. One theory of preconditioning’s memory that has never been proven nor disproved is the translocation of PKC hypothesis. Activation
of PKCs requires the physical translocation of the enzymes to their docking sites. It was proposed early on that
such translocations would position the kinase for early
phosphorylation of substrate with a subsequent occlusion
(209).
Kitakaze et al. (173) proposed that the memory in
preconditioning is due to the activation of 5⬘-nucleotidase
by PKC. When activated the heart would generate more
adenosine from the breakdown of ATP during ischemia,
and the adenosine would directly protect the heart. In that
case the PKC would be the trigger and adenosine the
mediator. The evidence supporting this was that blockade
of 5⬘-nucleotidase blocked the protection of preconditioning in a dog model (173). There are several arguments to
this hypothesis however. Although a PKC inhibitor could
block protection triggered by adenosine in rabbits, an
adenosine receptor blocker could not block protection
from a PKC activator (149). That would put adenosine
upstream of PKC rather than downstream. Subsequently,
Silva et al. (315) found that augmenting interstitial adenosine manyfold during ischemia with an adenosine deaminase inhibitor offered no limitation of infarct size in the
dog heart, indicating that elevated adenosine during ischemia alone does not protect. Protection must be triggered
by adenosine receptor occupation before ischemia. More
than likely the blockade of 5⬘-nucleotidase in Kitakaze’s
experiment simply removed the adenosine trigger for preconditioning.
MYOCARDIAL PRECONDITIONING
Physiol Rev • VOL
and it activates c-raf (105). To further complicate matters,
some of the above kinases have been implicated in ischemic
preconditioning by various investigators.
3. Phosphatidylinositol 3-kinase
Recent evidence has implicated phosphatidylinositol
3-OH kinase (PI 3-kinase) in the signaling of classical
preconditioning. Tong et al. (352) were first to report that
the PI 3-kinase inhibitor wortmannin could block protection from preconditioning using contractile dysfunction
as the end point. That was subsequently confirmed by
Mocanu et al. (233) using an infarct size model. PI 3-kinase has been implicated as protective in other cell systems (90). The question with respect to preconditioning
is, where is PI 3-kinase located in the signaling system?
This is discussed in more detail in section IIIC5.
C. KATP Channels
1. What are KATP channels?
KATP channels have been shown over the last 10
years to be an important mediator of cardioprotection,
and their role in ischemic preconditioning has been demonstrated in whole animals, isolated hearts, and cardiac
myocytes. KATP channels were first described by Noma
(249) in cardiac ventricular myocytes. These potassium
channels are termed ATP sensitive because they are normally inhibited by physiological levels of ATP. KATP channels are modulated by pH, fatty acids, NO, SH-redox state,
various nucleotides, G proteins, and various ligands
(adenosine, acetylcholine, etc.) (102, 172).
With regard to preconditioning, there is general consensus that KATP channel plays a key role in preconditioning. Gross et al. (129) were the first to propose that
opening of the KATP channel was involved in preconditioning’s protection. Studies have shown that not only do
KATP channel openers mimic preconditioning, but that
blockers abolish the ischemic preconditioning’s protection (7, 129, 305, 362). Further studies have shown that the
preconditioning mimicked by adenosine A1 receptor stimulation can also be abolished by glibenclamide, suggesting adenosine receptor activation to be upstream of KATP
channel activation (131, 362).
2. The mitoKATP channels
It was initially assumed that the sarcolemmal KATP
channel was the end-effector of preconditioning’s protection, and this protection was originally ascribed to shortening of the action potential (for review, see Ref. 130). At
the time of these early observations it was not appreciated that cardiomyocytes contained two different types of
KATP channels, sarcolemmal (surface KATP) and mitochondrial (mitoKATP), and that each had a distinct phar-
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
The activation patterns of p38 MAPK in ischemic
heart vary widely between reports. p38 MAPK, like all of
the MAPKs, has two amino acids that must be phosphorylated for activation: a threonine residue at amino acid
180 and a tyrosine residue at site 182. This kinase is
activated by MAPK kinase (MEK) 3 and 6, which in turn
are activated by MAPK kinase kinases (MKK). The phosphorylation of p38 MAPK can be measured with phosphospecific antibodies. p38 MAPK is phosphorylated
within minutes during global or regional no-flow ischemia
in isolated rat hearts (43, 105, 221), as well as in rat (311,
407), dog (291), and pig hearts in vivo (24, 33).
With prolongation of ischemia, however, the phosphorylation of p38 MAPK may be reduced toward preischemic
values, whereas phosphorylation is once again increased
upon reperfusion (311, 407). The transient p38 MAPK activation during prolonged ischemia might be related to decreased phosphorylation or increased dephosphorylation by
phosphatases (for review, see Ref. 299). In contrast to the
above studies, no activation of p38 MAPK by ischemia per se
is seen in nonpreconditioned isolated rabbit hearts (211, 244,
377). Following ischemic preconditioning, phosphorylation
of p38 during the index ischemia is reported to be increased
in isolated rat and rabbit hearts (220, 221, 244, 377), unaltered in pig hearts in vivo (33), and even decreased in dog
hearts in vivo (291). Ischemic preconditioning reportedly
prevents the ischemia-induced activation of p38 ␣-MAPK in
rat cardiomyocytes (298). At present, it is difficult to see any
consistent pattern in the data. Much of the variability in the
above reports may stem from technical problems in the
processing of the tissue as phosphatases remove these phosphate groups quickly and dephosphorylation can occur with
freezing and thawing in the presence of even the best phosphatase inhibitors.
The importance of p38 activation for cardioprotection also is controversial. Rat cardiomyocytes transfected
with a dominant negative p38 isoform, which prevents
ischemia-induced p38 activation, are more resistant to
lethal simulated ischemia (298). Similarly, in isolated rat
hearts (300) and pig hearts in vivo (24), blockade of p38
with SB 203580 did not affect the infarct size reduction
achieved by ischemic preconditioning, but reduced infarct size in nonpreconditioned hearts. In total contrast,
SB 203580 effectively blocked preconditioning’s protection in other cell models (13, 242, 377) and abolished the
infarct size reduction of ischemic preconditioning in isolated rat heart (221, 232) and the isolated rabbit heart
(245) and dog hearts in vivo (291).
Explanations for the controversial findings might relate
to the relative balance between different isoforms of p38 in
different species and experimental models as well as the
selectivity of different inhibitors in a given dose range. SB
203580, for example, not only inhibits p38 MAPK (81), but
also dose-dependently inhibits JNK (68), tyrosine kinases
such as p56 lck and c-src (370), and cyclooxygenase (50),
1121
1122
DEREK M. YELLON AND JAMES M. DOWNEY
3. How mitoKATP channels could be protective
The mitochondria make ATP by allowing H⫹ extruded by the electron transport apparatus to reenter
along a strong electrochemical gradient through the F1
apparatus. In so doing ADP is phosphorylated to ATP.
Opening the KATP channel will cause potassium to enter
mitochondria along its favorable electrochemical gradient. A potassium/hydrogen exchanger on the inner mitochondrial membrane allows intramitochondrial potassium to exchange for extramitochondrial H⫹. Entering H⫹
would theoretically uncouple the mitochondrion because
it bypasses F1 and hence reduces ATP production. In
actuality, however, the amount of uncoupling resulting
Physiol Rev • VOL
from potassium entry is very small (estimated to be ⬃5
mV), assumed to be caused by a low density of channels
in the inner membrane (114). Terzic’s group has reported
the greatest change, which was 10 mV with a baseline of
⫺180 mV in isolated mitochondria (143). These data were
confirmed in the intact cell by Minners et al. (227a). The
potassium that enters is, however, osmotically active and
will cause the matrix to swell.
There are several theories that seek to explain why
opening the mitoKATP channels should be protective. Terzic and co-workers (144) found that opening mitoKATP
channels made isolated mitochondria more resistant to
Ca2⫹ entry. Garlid and co-workers (95, 189) suggest that
mitochondrial swelling subsequent to potassium entry
causes preservation of the functional coupling between
mitochondrial creatine kinase and adenine nucleotide
translocase on the outer membrane through which ADP
traditionally enters the intermembrane space. That juxtaposition effectively keeps ADP out of the intermembrane
space and forces the mitochondria to phosphorylate only
creatine, which is the most efficient means of transferring
energy to the cytoplasm. Of course all of these theories
assume that the mitoKATP channel is the end-effector of
preconditioning’s protection.
4. Trigger role of mitoKATP channels
Recent experiments have reexamined the assumption that mitoKATP channels are only the end-effectors of
protection. Liu et al. (208) introduced a cardiomyocyte
model in which FADH fluorescence was monitored. The
slight uncoupling with mitoKATP channel opening was
proposed to slightly oxidize the flavoproteins and increase their fluorescence. These fluorescence studies
showed that the effects of both diazoxide and 5-HD are
readily reversible when the drugs are washed out. Yet
Ashraf’s group (376) reported that a 5-min pulse of diazoxide followed by washout put the rat heart into a preconditioned state even though the mitoKATP channels
should have reclosed when the index ischemia began.
Pain et al. (260) repeated the above experiment in the
isolated rabbit heart and found that a 5-min pulse of
diazoxide indeed protected the heart against infarction
and that the drug could be washed out for as long as 30
min without loss of the protection. Pinacidil, a nonselective KATP channel opener, had the same effect. These data
suggested that transient opening of mitoKATP channels
puts the heart into a preconditioned state that continued
long after the channel should have closed again.
Pain et al. (260) further studied the timing of channel
opening required to protect ischemic hearts. They set out
to determine whether mitoKATP channel opening was a
trigger or mediator of protection. As explained above,
triggers act before the index ischemia while mediators act
during the index ischemia and therefore must be down-
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
macological profile. However, Garlid et al. (115) and Liu
et al. (208) subsequently provided convincing evidence in
a recovery of function models and a cardiomyocyte
model, respectively, that it was not the surface but the
mitoKATP channel that was responsible for the protection.
Although some data, particularly studies using HMR 1098,
a selective sarcolemmal KATP channel blocker (342), still
suggest a critical role for the sarcolemmal KATP channel,
most evidence is consistent with the mitochondrial rather
than the surface channel as being most important. It should
be kept in mind, of course, that virtually all of that theory
hinges on pharmacological evidence that could still prove to
be flawed.
The KATP channel consists of an inward rectifying
potassium channel (Kir) in association with a sulfonylurea binding protein (Sur). Several isoforms of each exist,
and the channels can assemble in different combinations.
The mitoKATP channel is thought to have a similar structure to the sarcolemmal KATP channel with both a Kir and
Sur subunit, although the exact composition of the mito
KATP channel has not been resolved. However, there are
differential pharmacological responses of the cardiac sarcolemmal and mitoKATP channels. 5-Hydroxydecanoate
(5-HD) inhibits mitoKATP channels in the micromolar range,
but not sarcolemmal KATP channels under any concentration. Diazoxide, a KATP channel opener, has been shown to
be 1,000 times more potent in opening mitoKATP channels
than sarcolemmal KATP channels (116).
In addition, diazoxide-induced cardioprotection has
been demonstrated in the micromolar range without any
action potential duration (APD) shortening, excluding
sarcolemmal KATP channel involvement (115). Baines et
al. (18) were the first to show that diazoxide could limit
infarct size and that 5-HD could block the anti-infarct
effect of both diazoxide and ischemic preconditioning.
Not all data are supportive of the mitoKATP role in preconditioning. Recently, Kir6.2 knock-out mice were found
to have no functioning sarcolemmal KATP channels and
also could not be preconditioned despite the fact that
their mitoKATP were still intact (325).
MYOCARDIAL PRECONDITIONING
Physiol Rev • VOL
If mitoKATP channel opening is an upstream event,
then where in the pathway are the signaling kinases located? Ashraf’s group (376) showed that the PKC blocker
chelerythrine could block protection from a pulse of diazoxide in the isolated rat heart. While Pain et al. (260)
could not show a similar result in the rabbit heart, they
were able to block diazoxide’s protection with the tyrosine kinase blocker genistein, indicating that there was
at least one tyrosine kinase downstream from mitoKATP
channel opening in the rabbit model. Thus mitoKATP channel opening protects by activating kinases. This further
indicates that mitoKATP channel opening acts as an upstream link in a signal transduction chain leading to kinase activation. But how could channel opening be a
signal?
5. Free radicals and mitoKATP channels
Steenbergen and co-workers (108) provided the solution to this puzzle. They found that diazoxide’s protection could be blocked by a free radical scavenger, N-acetylcysteine. Their observation was then confirmed by Pain
et al. (260) who used the scavenger N-2-(mercaptopropionyl)glycine (MPG) in a similar experiment. Yao et al. (400)
found that pharmacological preconditioning of chick cardiomyocytes with the muscarinic agonist acetylcholine
caused the cells to produce a small burst of free radicals.
Yao et al. (407) used the probe 2⬘,7⬘-dichlorofluorescin
diacetate (DCFH) which fluoresces when oxidized by free
radicals. This burst could be blocked by myxothiazol (31,
186), indicating that the increased radical production was
the result of electron transport within the mitochondria,
probably from site III of the electron transport chain
where myxothiazol blocks the flow of electrons (for review of free radicals and their cellular origins, see Ref.
98). Furthermore, the burst could be blocked by 5-HD.
These observations led Pain et al. (260) to propose a new
paradigm incorporating mitoKATP channels and free radicals in PC’s signaling pathway leading to protection. In
this model receptor occupancy leads to mitoKATP channel
opening, which then causes the mitochondria to produce
reactive oxygen species (ROS). The free radicals would
then activate the downstream kinases that ultimately
modulate the end-effector.
Support for the free radical hypothesis was gained by
the observation that diazoxide increased free radical production in isolated cardiomyocytes (108) in a human atrial-derived cell line (60) and in vascular smooth muscle
cells (186). In all cases the increase in radical production
could be blocked by 5-HD. More recently, Oldenburg et al.
(254) have shown that exposure of smooth muscle cells to
acetylcholine, an agonist known to trigger preconditioning, causes a similar burst of radicals that is dependent on
a muscarinic receptor, a pertussis toxin-sensitive G protein, PI 3-kinase, and mitoKATP channels. Finally, Cohen
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
stream events. If KATP opening is the end-effector of preconditioning, then it would be expected to fall into the
mediator category. To investigate whether the mitoKATP
channel is a trigger or mediator, both Pain et al. (260) and
Wang et al. (373) used isolated rabbit hearts and administration of 5-HD either only during the preconditioning
stimulus (early) or only during the index ischemia (late).
In both studies, early 5-HD blocked protection supporting
a trigger role. Pain et al. (260) were unable to block
protection with 5-HD given in the late protocol just before
the index ischemia and concluded that mitoKATP channels
were only triggers. Wang et al. (373) however could abort
protection if the concentration of 5-HD was increased
fourfold over that required to prevent protection in the
early protocol. They theorized that a higher concentration
may have been required because channel phosphorylation
reduced the potency of 5-HD for channel blockade (295).
The other possibility, of course, is that the higher concentration of 5-HD introduced a nonspecific effect. Thus,
while both investigative groups agree that mitoKATP channels act as a trigger of preconditioning, Wang et al. (373)
suggest that these channels may have a dual role as both
triggers and mediators.
Further support for mitoKATP channels as a mediator
comes from Gross and Auchampach (129) who infused
glibenclamide in dogs between the time of PC and the
index ischemia and blocked protection. Gres et al. (126)
recently addressed both of these issues in their pig model.
In the above study (129), glibenclamide was given right at
the onset of reperfusion after the preconditioning ischemia. The reperfusion, of course, would be the critical
time for reactive oxygen species formation and requires
open mitoKATP channels. When Gres et al. (126) gave the
glibenclamide with the onset of reperfusion, it indeed
blocked protection. However, if they delayed administration of the glibenclamide for 5 min but still included it
during the index ischemia, protection was unaffected,
arguing against any mediator role of KATP channels. When
they tested a higher concentration of glibenclamide, infarcts were larger but, unfortunately, this concentration
of glibenclamide also increased infarct size in nonpreconditioned hearts by a similar increment. On the other hand,
infarcts were not increased in nonpreconditioned hearts
with the high dose of 5-HD used by Wang et al. (373). Yao
et al. (399) also noted in their chick cell model that
protection from a PKC activator could be blocked when
5-HD was introduced only during the prolonged simulated
ischemia. Thus the current weight of evidence supports
both a trigger and a mediator role for the channel. An
attractive explanation of this dual role would be a scenario in which channel opening triggers a kinase cascade
that feeds back in a positive manner to keep the channel
open during the index ischemia.
1123
1124
DEREK M. YELLON AND JAMES M. DOWNEY
that the signal transduction pathway could be completed.
In support of that observation, several investigators found
that a period of total occlusion protected both pig (303)
and rabbit (107) hearts from a subsequent period of lowflow ischemia. Receptor-mediated opening of mitoKATP
channels during the total occlusion period would result in
ROS formation during the low-flow period when oxygen
was again available. Not all investigators agree on when
the ROS are formed, however. Becker et al. (31) report
significant ROS formation during simulated ischemia in
chick cardiomyocytes. Whether there is enough residual
oxygen available during a preconditioning ischemia to
make the ROS signal without reperfusion is currently
unknown.
6. Prostaglandins
Several studies have looked at prostaglandin pathways in ischemic preconditioning. Murphy et al. (237)
found that preconditioning’s preservation of postischemic
function in the rat model could be blocked by a 12lipoxygenase inhibitor. More recently, Gres et al. (127)
found that indomethacin, a cyclooxygenase blocker,
could abolish protection from a weak but not a strong
preconditioning protocol in open-chest pigs. Whether cyclooxygenase was acting in the trigger or mediator phase
was not investigated. Indomethacin could not block preconditioning in rabbits (205), and cyclooxygenase 1 and 2
knock-out mice could still be preconditioned (54). Clearly
the role of prostaglandin pathways in preconditioning
warrants further investigation.
FIG. 4. A proposed scheme for classical
ischemic preconditioning based on the available
data. Three receptors act to trigger protection.
The delta opioid and bradykinin B2 couple to
protein kinase C (PKC) and a parallel tyrosine
kinase (TK) through phosphatidylinositol (PI)
3-kinase, mitochondrial KATP channels, and oxygen radicals while adenosine A1/A3 receptors
couple directly. The kinases then act on the
end-effector, possibly the mitochondrial KATP
itself, to prevent opening of a mitochondrial
transition pore.
Physiol Rev • VOL
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
et al. (75) found that protection triggered by acetylcholine, bradykinin, norepinephrine, or morphine could be
blocked by either 5-HD or a free radical scavenger applied
during the trigger phase. The study of Cohen et al. (75)
was strong evidence that all of the above receptors couple
through the mitoKATP channel/free radical pathway. Interestingly, adenosine was different as neither the KATP
blocker nor the scavenger could affect its protection
when applied during the trigger phase. Downey and colleagues (75) proposed that adenosine must have had a
parallel coupling to the kinases. See Figure 4 for a diagram of the proposed signaling pathways for classical
preconditioning.
Qin et al. (282) found that the PI 3-kinase inhibitor
wortmannin could block protection from acetylcholine
but not from adenosine. Furthermore, it only blocked
when the wortmannin bracketed the drug infusion, suggesting that PI 3-kinase acted as a trigger. Unpublished
studies reveal that wortmannin does block the acetylcholine-induced burst of ROS in isolated cardiomyocytes and
that it is upstream of the mitoKATP channels. Based on
that, we would propose that it links the surface receptors
to the mitoKATP channel.
The hypothesis that free radicals participate in the
trigger signal for preconditioning may answer one of the
mysteries of preconditioning: why receptor stimulation
during a simple occlusion does not protect the heart.
During a prolonged occlusion receptor agonists would be
released, populate their receptors, and open the mitoKATP
channels. However, the oxygen would be lacking to fuel
the burst of ROS so that the signal would die out at that
point. Only with reperfusion could ROS be produced so
MYOCARDIAL PRECONDITIONING
D. Possible End-Effectors
1. Metabolic effects
nized that pretreatment with cyclosporin A is cardioprotective. However, it was not known whether the protection derived from its inhibitory effect on phosphatases
(378) or its inhibition of transition pore opening (128).
Yellon’s group (137) recently proposed that ischemic preconditioning might act to prevent opening of this pore.
They demonstrated that protection from either ischemic
preconditioning, diazoxide or an adenosine agonist could
be blocked by actractyloside, an opener of the transition
pore. Actractyloside had no effect on infarct size in nonpreconditioned hearts. Diazoxide also inhibited calciuminduced pore opening in isolated mitochondria. This is
persuasive evidence supporting the transition pore as the
end-effector of preconditioning. Arguing against inhibition of the transition pore as an end-effector of preconditioning is a recent study by Garlid’s group (95). In that
study mitochondria isolated from ischemic hearts showed
no difference in state 2 respiration compared with those
from nonischemic hearts. That would not be expected if a
transition pore had opened in these mitochondria. In that
study the outer mitochondrial membranes did show an
increased permeability to proteins which preconditioning
prevented, however.
4. The sodium/hydrogen exchanger
2. The mitoKATP channel
The mitoKATP channel remains a viable candidate.
Particularly in light of compelling evidence that it must
reopen during the index ischemia, the likely time where
the end-effector is exerting its effect. How the opening
would protect the ischemic heart is not so clear as it will
cause a slight uncoupling of the mitochondria and swelling (for a review, see Ref. 114); neither effect would be
expected to protect. Terzic’s group (144) finds that KATP
channel openers make the mitochondria resistant to calcium overload. Perhaps opening mitoKATP channels prevent opening of the mitochondrial transition pore (156)
during deep ischemia. Indeed, in a paper recently published, Hausenloy et al. (137) describes a new paradigm
for preconditioning in which opening the mitoKATP channel could act to prevent opening of the mitochondrial
transition pore described below.
3. Mitochondrial permeability transition pore
Halestrap et al. (135) proposed that ROS generation
at reperfusion plus calcium entering the cell could cause
adenine nucleotide translocase (ANT) to open a largediameter pore within the mitochondrial membranes. The
pore formation involves the binding of mitochondrial cyclophilins to the ANT and can be prevented by treating the
hearts with cyclosporin A which binds the cyclophilins.
The transition pore disrupts mitochondrial function and
allows foreign substances into the matrix, which effectively destroys the mitochondria. It has long been recogPhysiol Rev • VOL
Xaio and Allen (386) have suggested that the sodium/
proton exchanger might be the end-effector of ischemic
preconditioning and that its inhibition might lead to protection of the ischemic heart. Certainly pharmacological
inhibition of the exchanger is one of the most potent
protectors of the ischemic heart yet discovered (165).
Xaio and Allen noted that the sodium/proton exchanger
appeared to be blocked at reperfusion only when rat
hearts had been preconditioned. Addition of HOE 642, a
highly selective blocker of the sodium/proton exchanger,
shortly before reperfusion to a nonpreconditioned heart
preserved postischemic function by an amount equal to
that achieved by ischemic preconditioning. HOE 642 had
no additive effect when combined with ischemic preconditioning, further suggesting a common mechanism. Similarly, 5-(N-ethyl-N-isopropyl)amiloride, another blocker
of the sodium/proton exchanger, limited infarct size in
rabbits by an amount equal to that of preconditioning, and
it could not augment preconditioning’s anti-infarct effect
(293). Neither kinase inhibitors nor 5-HD could abolish
amiloride’s protection, suggesting that the sodium/proton
exchanger must be protective as an end-effector. Probably the most serious criticism of the hypothesis is the
PKC, a key step in preconditioning acts to activate rather
than inhibit the exchanger (164).
5. Osmotic swelling
Cells are in osmotic equilibrium and cannot tolerate
an osmotic imbalance. Osmotic balance is maintained by
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
The end-effector of preconditioning has been amazingly elusive. After more than a decade and a half of
intensive research, the actual mechanism whereby the
cell is protected against lethal injury is an enigma. There
have been many theories over the years. The oldest theory
was that of Murry et al. (241), who suggested an improved
energy balance in the preconditioned ischemic myocardium. They proposed that perhaps the mitochondrial ATPase activity had been inhibited in these hearts. Although
energetics are improved in preconditioned hearts, there is
convincing evidence that that may not be the mechanism.
In some protocols the favorable energy balance during
ischemia may not be great enough to overcome the initial
deficit caused by the preconditioning ischemia itself. Kolocassides et al. (182) found that their ischemically preconditioned rat hearts actually went into contracture earlier and had consistently lower ATP levels during the
index ischemia despite obvious protection. The preconditioned hearts recovered from contracture during reperfusion, whereas the nonpreconditioned hearts did not.
1125
1126
DEREK M. YELLON AND JAMES M. DOWNEY
6. Decreased cytoskeletal fragility
If the preconditioned heart cannot alter the transmembrane osmotic forces, then it might modify the cytoskeleton to better withstand the swelling. VanderHeide
Physiol Rev • VOL
and Ganote (360) were the first to suggest that ischemic
myocytes might be more susceptible to osmotic rupture.
While oxygenated myocytes could withstand a hyposmotic shock, those subjected to an ischemic insult could
not. They attributed this to cytoskeletal lesions accompanying ischemia (112), possibly due to loss of phosphorylation of key cytoskeletal proteins (14). Preconditioned
myocytes also seemed to be protected against the development of osmotic fragility during simulated ischemia
(12). This theory ties in with the p38 MAPK hypothesis of
preconditioning nicely, since activation of p38 through
MAPKAPK2 causes phosphorylation of the small heat
shock proteins hsp27 and its smaller isoform, ␣␤-crystallin, which in turn causes actin filament assembly in the
cytoskeleton (132) and is very protective in other cell
types (146). As noted above, the evidence supporting p38
MAPK is controversial. Nevertheless, Eaton et al. (100)
did correlate phosphorylation of ␣␤-crystallin with protection from ischemic preconditioning in rat hearts. Holly
et al. (141) reported a translocation of hsp27 and ␣␤crystallin to the cytoskeleton after preconditioning. Dana
et al. (87) also correlated hsp27 phosphorylation with
preconditioning’s protection in a SWOP model of preconditioning. On the other hand, Armstrong et al. (13) could
not correlate phosphorylation of hsp27 with protection in
preconditioned rabbit cardiomyocytes.
7. Apoptosis
Another possible tie in with the MAPKs would be an
antiapoptotic effect of preconditioning. Gottlieb et al.
(123) proposed that ischemia/reperfusion triggers programmed cell death in the heart and that much of the
tissue loss is a direct result of triggered apoptosis (for a
review of apoptosis in infarction, see Ref. 10). Preconditioning has been reported to lower the levels of proapoptotic BAX protein in the heart (243) and prevent caspase
activation during ischemia/reperfusion (276). Caspase inhibitors are reported to mimic preconditioning by limiting
infarct size in some studies (142, 231, 401) but not in
others (251). Ohno et al. (250a) pointed out that the
commonly used marker for apoptosis (nick end-labeling
by TUNEL method) was confined to cells which already
showed lethal oncotic (swelling) injury and thus may not
have been the actual cause of cell death. Another problem
with the apoptosis hypothesis is that it is difficult to kill a
cell quickly by disabling its nucleus. Hearts can live for
hours in the presence of complete protein synthesis inhibition (340). Yet, cell death is complete after only 2 h of
reperfusion. Thus it has not been resolved whether apoptosis is important in preconditioning or whether the
reduced apoptosis seen in preconditioned heart is secondary to protection from other mechanisms.
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
matching the osmotic pull of proteins and nucleotides
within the cell primarily by sodium outside the cell. Because the conductance of the sarcolemma to sodium is
very low, extracellular sodium is an efficient osmolyte.
That is why virtually every cell type excludes sodium and
maintains a negative resting membrane potential. During
ischemia ATP is broken down to AMP and two inorganic
phosphates, thus tripling the osmotic pull of the nucleotides. Similarly, failure of the sodium-potassium pumps
leads to sodium leak into the cell and thus a collapse of
the vital sodium gradient. Each millimolar increase in
osmolyte concentration exerts an additional 19 mmHg
transmembrane pressure. Indeed, Jennings and co-workers (381) proposed that osmotic swelling was the cause of
membrane failure and cell death in reperfused myocardium in 1974. During ischemia, movement of water into
the cell concentrates the extracellular fluid and thus limits
swelling. Upon reperfusion however, the extracellular
fluid is replaced with isotonic fluid and explosive swelling
ensues.
Preconditioning makes cardiomyocytes very resistant to membrane failure when they are challenged with
hypotonic media (12). In ischemically preconditioned rat
(169) and pig (292) hearts, the extent of myocardial
edema formation, along with infarct size, is reduced. Alterations in channels involved in cell volume regulation
therefore might be involved in the cardioprotection
achieved by ischemic preconditioning. Chloride channels
are involved in moment-to-moment volume regulation,
and Diaz et al. (93) hypothesized from experiments in
rabbit cardiomyocytes and isolated hearts that opening of
swelling-induced chloride channels was responsible for
the protection achieved by ischemic preconditioning.
However, their electrophysiological and infarct size data
could not be confirmed (140). There are also organic
osmolytes, such as taurine or sorbitol, which are involved
in ischemia/reperfusion damage. In anesthetized rats, taurine depletion indeed reduces infarct size following ischemia/reperfusion, with the relationship between myocardial taurine content and infarct size being almost linear
(6). Whether ischemic preconditioning alters myocardial
taurine is not known. Because the sodium/hydrogen exchanger can provide an avenue for sodium entry into the
ischemic cell, the osmotic effects of sodium entry should
not be overlooked. If the sodium/hydrogen exchanger
turns out to be the end-effector of preconditioning and its
inhibition to be the final step in the cascade leading to
protection, then the principal effect of its inhibition may
be prevention of swelling rather than calcium entry.
MYOCARDIAL PRECONDITIONING
8. Gap junctions
9. Free radicals
During the 1980s it was proposed that free radicals
might contribute to cell death in the reperfused hearts.
Although the early animal data were encouraging, there
was difficulty in repeating those studies as the infarct size
models became more robust (96, 177, 285). To absolutely
prove that free radicals contribute to cell death in ischemia reperfusion injury, one would have to unambiguously show that a free radical scavenger introduced at
reperfusion can reduce infarct size. That has never been
done to the satisfaction of all. Nevertheless, the hypothesis persists since it has never been disproven either.
Accordingly, preconditioning may act to reduce the free
radical production at reperfusion. Turrens et al. (356)
measured antioxidants in preconditioned hearts and
found no difference from that in nonpreconditioned
hearts. On the other hand, Steeves et al. (319) did report
an increase in antioxidants in preconditioned rat hearts.
Vanden Hoek et al. (359) using a cell model did see less
radical production at reperfusion in preconditioned chick
cardiomyocytes, supporting a free radical hypothesis. Arguing against the possibility that reduced radical production could have simply been the result of less injury in
those cells was the observation that scavengers mimicked
the preconditioning. Also in support of a free radical
hypothesis is the observation that superoxide dismutase
is increased in hearts with the second window preconditioning (see sect. IVD2).
ischemia and that it was reduced in hearts preconditioned
with adenosine. It has also been reported that ischemic
preconditioning reduced TNF-␣ in in situ rabbit hearts
during ischemia. The protected hearts showed an increase in TNF-␣ inhibitory serum activity which could
account for the reduced TNF-␣ (38). The same effect on
TNF-␣ was seen in a SWOP model where rabbits were
exposed to lipopolysaccharide 3 days before the ischemic
insult (38). Interestingly, TNF-␣ has also been proposed to
act as a trigger for preconditioning protection. Yamashita
et al. (393) found that antibodies against TNF-␣ could
abolish the induction of both Mn-SOD and SWOP against
infarction from ischemic preconditioning in rat hearts.
Most recently, Smith et al. (316) found that TNF-␣ knockout mice could not be acutely preconditioned by ischemia
but could still be protected with either adenosine or diazoxide. Furthermore, a transient exposure to exogenous
TNF-␣ put the wild hearts into a preconditioned state but
inexplicably could not protect the TNF-␣ knock-outs.
E. Summary of Classic Preconditioning
Although much has been found concerning the cellular mechanisms of ischemic preconditioning, there are
still glaring gaps in our knowledge. We can be certain that
surface receptors, KATP, free radicals, and PKC all play
pivotal roles in the signaling of the protective signals.
Beyond that we find very conflicting reports as to the
exact details of these signaling pathways. It is even not
certain whether the KATP channel is on the surface or the
mitochondria. Whether KATP merely plays a signal transduction role or whether it is the end-effector still remains
to be established. Although a number of other end-effectors have been proposed such as the permeability transition pore, sodium/hydrogen exchanger, apoptosis, gap
junctions, etc., there is insufficient data available to support any one to the exclusion of the others. The difficulty
is that all of these studies have led us to fields where the
technology is clearly lacking. Until novel techniques are
developed which allow us to work with things like the
transition pore, mitoKATP, or gap junctions, these hypotheses will be difficult to prove.
IV. NATURAL HISTORY OF THE SECOND
WINDOW OF PROTECTION
10. Tumor necrosis factor-␣
A. What is SWOP?
There is compelling evidence that the toxic autacoids
tumor necrosis factor-␣ (TNF-␣) may play a role in preconditioning. TNF-␣ was originally proposed to contribute to ischemic cell death. Meldrum et al. (223) found that
even crystalloid-perfused rat hearts made TNF-␣ during
In 1993 it was reported that if the intervening period
of reperfusion between the preconditioning and the test
ischemia is extended to 24 h, a delayed phase of myocardial protection is induced (188, 213), which although not
as powerful as the early phase, is more prolonged and
Physiol Rev • VOL
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
An intriguing hypothesis is that preconditioning may
act to close gap junctions in the heart. It has been known
for a long time that infarcts tend to be confluent, suggesting that necrosis spreads from one cell to the next. This
spread could occur through gap junctions, the low-resistance channels between adjacent heart muscle cells.
Transgenic mice deficient in connexin43 (a major component of cardiac gap junctions) could no longer be protected by preconditioning (306). Heptanol, a closer of gap
junctions, also blocked the protective effect of preconditioning in isolated mouse hearts (199). The above studies
suggest that opening of gap junctions rather than closing
them is the protective step. Conversely, heptanol appeared to mimic preconditioning in isolated rabbit hearts
(290). For a comprehensive review on this subject, see
Reference 113.
1127
1128
DEREK M. YELLON AND JAMES M. DOWNEY
B. Triggers
1. Adenosine
The SWOP can be stimulated by a spectrum of nonpharmacological and pharmacological stimuli. The former
include ischemia, heat stress, rapid ventricular pacing,
and exercise, while the latter include adenosine receptor
agonists, bradykinin, opioid agonists, NO donors, cytokines, ROS, and endotoxin (e.g., monophosphoryl lipid
A). Interestingly, the triggers appear mostly identical to
those of acute ischemic preconditioning, although there
appears to be significant interspecies variation with respect to the relative importance of each trigger: adenosine, NO, ROS (324), and opioid receptor agonists (109)
are all important.
Yellon and colleagues (27) were the first to show
adenosine receptor involvement in the delayed phase of
myocardial protection 24 h after ischemic preconditioning. They went on to demonstrate the temporal nature of
this delayed effect with the adenosine A1 receptor agonist, which lasted up to 72 h (29), was very similar to that
seen when preconditioning was induced with ischemia
(26). Studies using receptor stimulation to produce a
Physiol Rev • VOL
delayed protective effect have also been seen in other
species including the rat (86).
Interestingly, adenosine acting on A1 and possibly A3
receptors (327) was able to trigger a SWOP against infarction but not against myocardial stunning (16). Tsuchida et
al. (355) undertook studies in which they tried to maintain
the heart in a classic preconditioning state by giving a
continuous infusion of 2-chloro-N 6-cyclopentyladenosine
(CCPA) but were unable to demonstrate any protection
which they attributed to a desensitization of the A1 receptor. Dana et al. (84) however tried to overcome this
potential problem by giving repeated administration of
CCPA at 48-h intervals for a 10-day period and were able
to maintain a continuous protective effect against infarction over the entire time without any evidence of adenosine A1 receptor downregulation.
2. NO
NO has been shown to play an important but as yet
undefined role in delayed preconditioning against both MI
and myocardial stunning (329). Indeed, NO generated in
ischemic tissue has been proposed to act as both a trigger
as well as distal mediator of SWOP by Bolli and colleagues (44, 46). This group demonstrated that NOS inhibition blocks the SWOP (328), and pretreatment with NO
donors in the absence of ischemia induces a similar delayed protective effect (133). Indeed, Bolli et al. (46) were
the first to come up with the so-called NO hypothesis of
late preconditioning. As mentioned above they propose
that NO has a bifunctional role in delayed preconditioning. eNOS triggers the release of NO in association with
the preconditioning stimulus, and inducible NO synthase
(iNOS) then mediates the formation of NO 24 –72 h later
to protect against subsequent ischemia. This hypothesis is
supported by direct measurements of NOS activity that
show a biphasic regulatory pattern (388).
Bolli’s group (47, 328) further investigated the role of
NO in delayed preconditioning using the NO blocker NGnitro-L-arginine (L-NA) administered 24 h after an ischemic preconditioning protocol. They clearly showed that
it blocked the preconditioning protection against infarction (328) as well as against stunning (47) in conscious
rabbits. A number of studies using the mouse heart with
targeted disruption of the iNOS gene have demonstrated
that iNOS is pivotal to the mediation of the SWOP. In this
regard Bolli and colleagues (133) using ischemia as a
preconditioning trigger were unable to demonstrate any
protection in the in vivo iNOS knock-out mouse. Furthermore, Kukreja and colleagues (385) using an in vitro iNOS
knock-out mouse model were similarly no longer able to
protect with the endotoxin derivative monophosphoryl
lipid A, a pharmacological trigger of SWOP. Interestingly,
Yellons’ group has suggested that although NO is essential
to the mediation of delayed protection, the source of this
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
lasts up to 72 h (26). This delayed phase of resistance to
ischemic injury as mentioned above has been termed by
Yellon’s group as the second window of protection or
SWOP (213), distinguishing it from early or “classic” preconditioning. SWOP has variously been referred to as
“delayed” or “late” preconditioning as well. It is likely that
these two forms of adaptation have different underlying
mechanisms, although they share the same trigger, transient ischemia.
Additional studies in rabbits (397) and rats (394) have
since confirmed these original findings. More recent evidence suggests that in addition to enhanced tolerance to
lethal ischemic injury, delayed preconditioning confers
protection against other end points of ischemia-reperfusion injury including ischemia and reperfusion-induced
ventricular arrhythmias (365) and postischemic myocardial dysfunction (stunning) (45, 323). The delayed protective effects of preconditioning have also been demonstrated in vitro, using isolated cardiomyocytes subjected
to simulated ischemia or hypoxia (82, 396).
Similar to classical preconditioning, SWOP can be
subdivided into the triggers that exert their actions during
the preconditioning ischemic period and mediators that
act during the subsequent index ischemia. The prolonged
interval between the preconditioning event and its renewed protection a day later allows for the possibility of
new protein synthesis, posttranslational protein modification, and a change in the compartmentalization of existing
proteins (404).
MYOCARDIAL PRECONDITIONING
3. Bradykinin
We know that many of the triggers of early preconditioning are also involved in the second window, and in
this regard bradykinin is no different. This has been observed in both the rat and rabbit heart (101, 184) In the
former study, bradykinin administered to rats resulted in
protection in infarction 24 h later. This effect was abolished if the rats were treated with L-NAME to inhibit NOS
before the bradykinin administration. That is in contrast
to studies in classical preconditioning where bradykinin
will also precondition the rabbit heart, but in that case
L-NAME had no effect against the protection (122). The
rabbits were either preconditioned with sublethal ischemia in the presence of the bradykinin B2 receptor
blocker HOE 140 or given bradykinin directly. When the
hearts were examined 24 h later, bradykinin was seen to
be equal to preconditioning in terms of myocardial protection. In addition, the HOE 140 completely abrogated
the protection seen following as a consequence of the
preconditioning stimulus. Both studies clearly demonstrate a role for the B2 receptor in delayed preconditioning.
Indirect evidence for the importance of bradykinin,
as a trigger of delayed preconditioning, also comes from
studies in pigs by Yellon’s group (155). Here they demonstrated that two 2-min periods of ischemia, caused by
Physiol Rev • VOL
balloon inflation in a coronary branch of pig hearts, were
insufficient to induce delayed protection. However, when
they administered an ACE inhibitor, concomitantly with
the subthreshold preconditioning stimulus, they could detect a fully protective response 24 h later. Since it is known
that ACE inhibition prevents the degradation of bradykinin,
these results add further to the evidence of the importance
of this peptide as a preconditioning mimetic.
4. Opioids
Although the evidence for a role for opioids in delayed preconditioning is still limited, a number of recent
studies have shown that opioids can act as triggers for
this phenomenon. In this regard Gross and colleagues
(109) were the first to show that a ␦-opioid agonist could
induce a delayed cardioprotection in the rat. This protection was associated with mitoKATP channel activation as
the mitochondrial blocker 5-HD and glibenclamide were
shown to abolish the effect of the ␦-opioid agonist TAN67. Furthermore, this study also demonstrated the temporal nature of the opioid agonist in that the protection they
observed was seen after 24- and 48-h treatment but was
lost by 72 h. In attempting to further investigate the
mechanism, this group has shown, using the rat, that this
delayed effect, as with early preconditioning, appears to
involve both ERK and p38 MAPK as integral components
of the cardioprotection (110). This was followed by studies in their laboratory where they used a specific ␦-opioid
agonist to demonstrate delayed cardioprotection via a free
radical mechanism that was only partially due to opioid
receptor stimulation (265). These ongoing studies are important as the use of agents, such as ␦-opioid agonists, may be
of clinical relevance in the setting of patients with acute
coronary symptoms who are at risk of MI.
5. Other proposed triggers
It is of interest to note that prostanoids have been
shown to produce a delayed form of cardioprotection for
many years. Indeed, Szekeres et al. (326) described how
7-oxoprostacyclin could induce a “delayed and long lasting” protection to the heart over a decade ago. This was
long before the second window or delayed preconditioning effect was first described (213).
Similarly, the administration of catecholamines, such
as norepinephrine, has also been shown to produce delayed cardioprotection in rats (225). In an earlier study
the same group (224) demonstrated how norepinephrine
could induce hsp70, which in turn was associated with
delayed cardioprotection in rat. Catecholamines could
either trigger the SWOP directly through the ␣1-receptors
or they might drive the heart into a demand ischemia
where other factors such as adenosine and bradykinin
could be the actual triggers of the preconditioned state.
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
NO need not necessarily be derived from iNOS. This was
first indicated in pharmacological studies using the adenosine A1 receptor agonist CCPA in which they were unable to abolish the second window using the specific iNOS
inhibitors L-N 6-(1-iminoethyl)-lysine (L-NIL) and aminoguanidine in rabbit (85). This contradictory result was
investigated in more detail by Bell et al. (35) in the iNOS
knock-out mouse. In these studies they found that CCPA
could elicit protection in iNOS knock-out mice concomitant with a significant upregulation of the eNOS protein.
Moreover, the protection was abrogated by a nonselective
NOS inhibitor, NG-nitro-L-arginine methyl ester (L-NAME).
These results suggest that in certain circumstances eNOS
can masquerade as iNOS to mediate protection. Further
support for this comes from data showing enhanced NO
in the myocardium following brief episodes of ischemia/
reperfusion, which is thought likely to be due to eNOS
since SWOP can be blocked by nonspecific NOS inhibition, but not by the selective iNOS inhibitors aminoguanidine and S-methylisothiourea (47).
Because of the evidence supporting NO as a trigger of
SWOP, it has also been examined in classical preconditioning. Isolated rabbit hearts continued to be protected
by ischemic preconditioning in the presence of L-NAME,
strongly arguing against such a trigger role (247). Interestingly, however, an NO donor could trigger a preconditioned state in that study.
1129
1130
DEREK M. YELLON AND JAMES M. DOWNEY
C. Mediators: Signal Transduction Pathways
1. PKC
2. Tyrosine kinases and MAPKs
Imagawa et al. (151) demonstrated a role for protein
tyrosine kinase in delayed preconditioning. They showed
that the protein tyrosine kinase inhibitor genistein abolished the protection seen 48 h after ischemically preconditioning the rabbit heart. Recent studies have also focused attention on two members of the Src family of
protein tyrosine kinases, namely, the Src and Lck. Protein
tyrosine kinase activation is blocked by the PKC inhibitor
chelerythrine, indicating the downstream position of the
protein tyrosine kinase in respect of PKC (275). Lavendustin A (LD-A) has also been shown to block protein
tyrosine kinase activation and abolish the delayed preconditioning against myocardial stunning (91). Furthermore,
Yellon and colleagues demonstrated that LD-A blocked
the adenosine A1 receptor agonist (CCPA)-induced SWOP
using infarct size as the end point (87), although the
Physiol Rev • VOL
D. Possible End-Effectors
1. Heat stress proteins
The first studies investigating the existence of a
SWOP were based on studies which demonstrated that
24 h after heat shock, a significant protection against
subsequent MI could be observed (for review, see Ref.
406). This protection was linked to the upregulation of the
72-kDa inducible heat stress protein (hsp72i). It was
known that ischemia, like heat shock, was also capable of
inducing the appearance of a cardiac mRNA coding for
proteins similar to hsp72i (94) as well as causing the rapid
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
Multiple signal cascades are activated in response to
transient reperfusion/reperfusion. PKC, protein tyrosine
kinase, and the MAPKs including the activation of various
transcription factors that are linked to the expression of
the cardioprotective genes such as nuclear factor-kappa B
(NF-␬B) are all thought to be part of the signaling mechanism of SWOP. For a comprehensive review, see Reference 19.
The first to demonstrate a role for PKC in the SWOP
was Yamashita et al. (396) who demonstrated that the
PKC inhibitor staurosporine could prevent the acquisition
of this phenomenon in hypoxically preconditioned myocytes. With regard to MI however, the first evidence indicating a role for PKC in the mechanism of delayed protection was seen in the rabbit model (25). Subsequently,
Qui et al. (283) demonstrated that, as in classic preconditioning, PKC is also an essential mediator of the second
window. This was followed by studies in which a PKC
agonist, dioctanoyl-sn-glycerol, was observed to cause a
significant reduction in infarct size in rabbit hearts 24 h
after administration (28). With regard to other end points
of injury, inhibition of PKC-⑀ translocation, using chelerythrine, completely blocked the delayed preconditioning against stunning (283). This PKC activation was seen
to be NO dependent and could be blocked by pretreatment with the nonselective NOS inhibitor L-NA (271).
Indeed, there have been a number of studies by Ping and
colleagues (272–275) demonstrating the importance of
PKC in delayed preconditioning against both stunning and
infarction. With regard to translocation of PKC-⑀ to the
membrane, this has also been shown to occur in dog
hearts following rapid cardiac pacing, which is associated
with protection against arrhythmias (383).
protection of heat shock-induced SWOP could not be
inhibited using genistein (163).
Maulik et al. (220) demonstrated that ischemic preconditioning could trigger activation of MAPK in rat
hearts (220). Unfortunately, the role of MAPKs in SWOP
remains unresolved, primarily due to variations in experimental protocols. All three MAPK subfamilies, namely,
the p42/p44 MAPK, the p38 MAPK, and the JNKs are
induced by a SWOP protocol in a rabbit model. In that
study infarct size measurement and MAPK activation
were studied in different animals (272, 273). However, in
a pig model, no correlation between infarct size reduction
and MAPK activation (measured within the same animal)
could be demonstrated (33). Furthermore, using isolated
myocytes, Heads and colleagues (235) have shown that
metabolic inhibition can induce delayed preconditioning,
an effect which is PKC dependent but independent of
MAPK activation. Thus further research in this area is
needed to confirm the precise role of MAPKs in this form
of preconditioning.
The transcriptional regulator NF-␬B is responsible
for the modulation of many genes. It may well be a
common downstream pathway through which multiple
signals generated by ischemia (NO, ROS, PKC, and protein tyrosine kinases) are able to initiate cardiac gene
expression. Both ischemic preconditioning and NO donors are able to induce NF-␬B activation (387). Conversely, Xuan et al. (387) were able to abrogate SWOP by
the direct inhibition of NF-␬B. At the same time activation
of NF-␬B following an ischemic preconditioning protocol
was disrupted by pretreating with known blockers of
SWOP, including the NOS inhibitor L-NA, mercaptopropionyl glycine (an antioxidant), chelerythrine, and LD-A.
It is possible that other stress-responsive transcription
factors, e.g., activating protein 1, may play a similar role in
focusing the SWOP effect. It should also be noted however that NF-␬B, as well as other transcription factors,
can also be activated by prolonged ischemia (irrespective
of a preconditioning stimuli), which in itself may result in
inflammatory injury (63). See Figure 5 for a diagram of the
proposed signaling pathways involved in SWOP.
1131
MYOCARDIAL PRECONDITIONING
and direct expression of heat shock proteins in rabbit
heart after brief ischemia (180). It was, therefore, hypothesized that it should also be possible to see significant
protection 24 h after ischemic preconditioning. This indeed proved to be the case, and it was subsequently
demonstrated in rabbits that 24 h after an ischemic preconditioning stimulus, there was an increase in hsp72i as
well as a significant reduction in MI (213). This group
provided further evidence of protection using transgenic
mice overexpressing hsp72 (214). Subsequent studies in
which the human hsp72 gene was transfected directly into
cardiac-derived cell lines (138) and myotubules (42) also
demonstrated protection against subsequent hypoxic injury. However, it must be noted that some studies have
not supported this hypothesis, with some reporting no
hsp72 induction in rabbits preconditioned with ischemia
(333). Rats exposed to ischemic preconditioning have
also not had sufficient elevation of hsp72 to correlate with
protection against infarction (281). The smaller heat
shock proteins, i.e., hsp27 and ␣␤-crystallin, have also
been implicated in the second window and could act via
Physiol Rev • VOL
the cytoskeletal mechanism described above (see sect.
VD6). Interestingly, although it has been shown that pharmacological induction of delayed preconditioning can occur using an adenosine A1 receptor agonist, the resulting
protection has been linked to the smaller hsp27 rather
than hsp72 (87). Thus the relative importance of the heat
stress proteins in delayed preconditioning are as yet unresolved and more work needs to be undertaken to define
their precise role.
2. Antioxidant enzyme systems
The antioxidant enzyme systems are another group
of proteins that show either increased transcription or
functional upregulation. The three main enzyme systems
in the heart are superoxide dismutase (SOD), catalase,
and glutathione peroxidase. The SODs are a family of
metalloenzymes responsible for the dismutation of O⫺
2.
Hoshida et al. (145) were the first to demonstrate an
increase in MnSOD activity (mitochondrial origin) in ischemic versus nonischemic myocardium immediately fol-
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
FIG. 5. A flow chart depicting the proposed
mechanisms in the second window of protection
(SWOP).
1132
DEREK M. YELLON AND JAMES M. DOWNEY
3. Cyclooxygenase
A recent development from Bolli’s laboratory (312)
proposes that cyclooxygenase (COX)-2 acts in the genesis
of SWOP. Increased COX-2 expression (with a concomitant rise in prostaglandin E2, I2, and F2␣) was found 24 h
after an ischemic preconditioning protocol in rabbits. The
cardioprotective effects of the SWOP were blocked following the administration of two unrelated COX-2-selective inhibitors at 24 h after the ischemic preconditioning
protocol. In addition, a COX-2 inhibitor was also found to
abolish delayed preconditioning against infarction in the
mouse heart (124). Confirmation of the potential importance of cyclooxygenase has recently been shown using
COX-1 and -2 knock-out mice in which a decrease in postischemic recovery of left ventricular diastolic pressure was
observed (55). How COX-2 mediates protection is not clear;
however, recent evidence appears to link inducible NOS to
Physiol Rev • VOL
the modulation of COX-2 activity in rabbit hearts (313). If
that proves to be true, it would reveal yet another important
role for NO in this protective phenomenon. In contrast to
COX-2-induced late preconditioning however, the mechanisms associated with adenosine A1 and A3 receptor-induced delayed protection appear independent of COX-2
(181). Thus further work is needed to confirm all the above
findings especially since COX-2 has previously been thought
of as detrimental to cellular survival (361).
4. The mitoKATP channel
As with classic preconditioning, attention has focused on the importance of these channels in delayed
preconditioning, specifically the role of the KATP channels
of the mitochondrial inner membrane rather than those
located on the sarcolemma. Pharmacological evidence
with inhibitors of KATP channel opening suggests that
these channels play a key role in conferring protection by
delayed preconditioning. While glibenclamide is an inhibitor of both channels, 5-HD inhibits mitochondrial channels selectively. Bernardo et al. (39) reported that delayed
preconditioning in rabbit was abolished when either glibenclamide or 5-HD was administered just before the index
ischemic insult, suggesting a critical role of KATP channel
opening. This was concluded to be due to the sarcolemmal KATP channel, since differences in monophasic action
potential duration were seen with both drugs. This observation does not sit easily with the fact that most workers
find that 5-HD has no effect on sarcolemmal KATP channel
currents. Nevertheless, the study tends to support the
idea that enhancement of some aspect of KATP channel
function is a pivotal event in mediating delayed preconditioning. Takano et al. (330) have recently confirmed that
5-HD given before index ischemia abolished delayed preconditioning against infarction but did not modify the
delayed antistunning effect of preconditioning.
Although it is unproven at present, it is possible that
upregulation of some protein associated with the KATP
channel alters its opening characteristics, and this determines the protection afforded by delayed preconditioning. Another possibility is that elevated NO levels, generated as a result of iNOS induction, modify KATP channel
activity. There is evidence that NO stimulates cGMPdependent protein kinase (PKG), which in turn can activate KATP channels. Whatever the precise molecular
mechanism, the pharmacological evidence with 5-HD
would tend to favor involvement of mitochondrial rather
than sarcolemmal KATP channels (207).
It is now known that delayed cardioprotection can be
induced by a variety of nonischemic stimuli, including
adenosine A1 agonists (30), ␦-opioid agonists (109), heat
stress (267), and monophosphoryl lipid A (222), and that
protection from all these stimuli are sensitive to inhibition
by either glibenclamide or 5-HD given just before the index
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
lowing preconditioning in the canine heart. This increased
activity was lost by 3 h and reappeared at 24 h after
ischemic preconditioning. MnSOD content was increased
at 12 and 24 h after preconditioning (indicating de novo
protein synthesis), but not at less than 6 h. No changes in
Cu/ZnSOD activity or protein content (cytoplasm origin)
were observed. Kuzuya et al. (188), from the same group,
were the first to demonstrate, in dog myocardium, that
following short periods of ischemia there was a delayed
protective effect against a subsequent lethal ischemic
insult 24 h later, an effect which they attribute to the
upregulation of antioxidant enzymes such as MnSOD
(145). They subsequently demonstrated the same effect in
rat cardiac myocytes (396) and more recently in the rat in
vivo (391). In this latter study they demonstrated that antisense oligonucleotides directed against manganese SOD
abolished the protection against infarction in vivo, strongly
implicating this antioxidant in delayed preconditioning. Furthermore, heat shock also induced MnSOD activity in rat
cardiac myocytes, and tolerance to hypoxia was abrogated
by the administration of MnSOD antisense oligodeoxynucleotides (hsp72 expression was unaffected) (390). Dana et al.
(86) showed that MnSOD activity was increased 24 h after
treatment with the adenosine A1 receptor agonist CCPA,
which was then attenuated by prior administration of PKC
and protein tyrosine kinase inhibitors (86). In vivo administration of antisense oligodeoxynucleotides to MnSOD has
now been reported to block ischemia-induced (391), heat
stress-induced (390), exercise-induced (392), and CCPA-induced (86) SWOP. However, it must be mentioned that not
all studies have found upregulation of antioxidant defenses
in the delayed preconditioning. In conscious pigs subjected
to ischemic preconditioning, Tang et al. (335) could detect
no change in MnSOD, Cu/ZnSOD, catalase, glutathione peroxidase, or glutathione reductase activity 24 h after the
preconditioning stimulus.
MYOCARDIAL PRECONDITIONING
ischemic event. Such evidence points to an intriguing common distal mechanism of action in delayed cardioprotection
studies. A further interesting development is that mitoKATP
channel openers such as diazoxide are able to induce pharmacological delayed preconditioning (250, 330). The possible mechanisms by which mitoKATP channel opening can act
as a signal transduction agent to activate kinases are discussed in section IIIC4. Indeed, Takashi et al. (331) have
reported that diazoxide can trigger a delayed protection via
a PKC-dependent mechanism.
5. NO
V. PRECONDITIONING HUMAN MYOCARDIUM
The question that emerges from the wealth of animalbased evidence indicating the importance and power of
the preconditioning phenomenon is whether this form of
protection can be seen in humans. Furthermore, if it can,
Physiol Rev • VOL
could it be exploited to design therapeutic strategies to
prophylactically protect the human heart against infarction?
The obvious ethical restrictions associated with
studying ischemic preconditioning in humans have been
ingeniously circumvented by studying surrogate end
points of reperfusion-reperfusion injury in experiments
using human ventricular myocytes, and atrial trabeculae
studies and in patients with naturally occurring ischemic
syndromes. In addition, studies of patients undergoing
planned procedures that involve brief periods of ischemia
such as coronary angioplasty (PTCA) and coronary artery
bypass surgery (CABG) have also been used to demonstrate that preconditioning can occur in patients at risk of
impending MI. In the following sections we review the
available evidence.
A. In Vitro Studies
1. Human cell preparations
Ikonomidis et al. (148) were the first to demonstrate
preconditioning in human ventricular myocytes in cell
culture using trypan blue exclusion and metabolic end
points of injury. This group has also demonstrated a role
for both adenosine and PKC in triggering and signaling
associated with preconditioning in this model (147). More
recently, work by Arstall et al. (15) provided direct evidence that in addition to classic preconditioning, human
ventricular myocytes, in vitro, also exhibited delayed cardioprotection 24 h after a short period of simulated ischemia. Interestingly, it has also been shown that preconditioning reduced cell injury in human myocytes but not in
human endothelial cells (314), although others, using human coronary arteriolar endothelial cells triggered by
hypoxic preconditioning, demonstrated an upregulation
of prosurvival kinases (414).
2. Human muscle preparations
Yellon’s group (371) were the first to investigate the
phenomenon of preconditioning using human atrial muscle obtained from patients undergoing coronary artery
bypass surgery. The atrial muscle, suspended in an organ
bath, was subjected to sustained periods of simulated
ischemia followed by reoxygenation before a sustained
lethal hypoxic insult followed by reoxygenation. They
were able to precondition human muscle using postischemic recovery of mechanical function as the end point
(371). They also demonstrated that adenosine A1 and A3
as well as ␦-opioid receptor activation all could trigger
this protection (37, 57) and that both PKC and the KATP
channel appear to be involved in mediating the protection
in human muscle (56, 58, 59, 317). These results have been
confirmed by Cleveland et al. (70). Furthermore, as with
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
As mentioned above, NO has been proposed as both
a trigger as well as end-effector of SWOP (46). Initially
Vegh et al. (366) demonstrated that delayed preconditioning against arrhythmias, induced by rapid pacing, was due
to the inhibition of NOS and cyclooxygenase induction
using the nonspecific agent dexamethasone. They proposed that this effect was due to an upregulation of iNOS
(366). Bollis’ group then provided strong evidence using
pharmacological studies (328) as well as studies in iNOS
knock-out mice (134) which demonstrated a role for iNOS
in mediating delayed preconditioning against myocardial
infarction in rabbits. Yellon’s group (151) had earlier demonstrated that dexamethasone given to rabbits before
ischemic preconditioning abrogated protection against infarction 48 h later. They also showed that aminoguanidine, a selective inhibitor of iNOS activity, before the
sustained ischemic insult, also abolished the protection. It
is important to note however that the upregulation of
iNOS with subsequent enhanced NOS production does
not appear to occur in all forms of delayed preconditioning. Although one can observe that SWOP is abolished by
inhibitors of iNOS (151, 328) in addition to being absent in
iNOS knock-out mice (134), the role of iNOS in delayed
pharmacological preconditioning, using adenosine A1 receptor agonists, is not clear. Some studies using such
agonists have been shown to induce delayed protection
against infarction, which is not abrogated by iNOS inhibitors (85) and can be demonstrated in animals in which
the iNOS gene has been disrupted (35). As mentioned
earlier, however, at least one other study reports the
opposite of this (413). We believe that it is difficult at this
stage to draw conclusions as to the the role of NOS with
relation to it acting as either a trigger or mediator (or
both) of delayed preconditioning (this section should be
read in conjunction with section IVB2).
1133
1134
DEREK M. YELLON AND JAMES M. DOWNEY
B. In Vivo Studies
cessive periods of exercise. A more recent study suggests
that the degree of myocardial stunning following exercise-induced myocardial ischemia may also be attenuated
if the patient had performed a preceding period of exercise 30 min earlier (286). Studies investigating the temporal profile of warm-up angina have demonstrated that the
duration of this phenomenon is 1–2 h after the first period
of exercise, a time course that closely parallels that of
classic ischemic preconditioning (320, 345).
These above findings suggest that the warm-up phenomenon is at least partly due to metabolic adaptation of
myocardium which induces tolerance to subsequent ischemia, a process that closely resembles ischemic preconditioning. However, studies that have examined the cellular mechanisms mediating warm-up angina do not fully
support this hypothesis. For instance, inhibition of adenosine receptors before exercise fails to abolish the
warm-up phenomenon (168). Furthermore, investigation
into the role of KATP channels in mediating this form of
myocardial adaptation has provided conflicting results
(78, 259, 350). It is therefore not clear at this point
whether the adaptation observed during repeated exercise is a true representation of the preconditioning phenomenon, or if other mechanisms are involved. In a recent
editorial Tomai (343) suggests that preconditioning might
play a role in the warm-up phenomenon but that it may be
mechanistically distinct from preconditioning caused by a
sudden interruption of oxygen supply.
1. Exercise-induced preconditioning
2. Preinfarction angina
It is known that some patients are able to exercise to
the point that they develop angina, rest, and then continue
exercising with minimal or no further development of
symptoms. This phenomenon, termed warm-up or firsteffort angina, was first described over 50 years ago and
for many years was thought to be mediated by coronary
vasodilatation and recruitment of collateral vessels resulting in improved blood supply to the ischemic myocardium
during the second period of exertion (212). Some investigations, however, suggest that other mechanisms might
be involved in warm-up angina. Studies examining hemodynamic and metabolic characteristics during consecutive exercise testing (252), or consecutive angina resulting
from pacing-induced tachycardia (382), have reported a
reduction in the severity of angina and the degree of S-T
segment depression during the second period of myocardial ischemia. These favorable changes were not accompanied by recruitment of collateral vessels as evidenced
by similar coronary and great cardiac vein blood flows
measurements. However, Okazaki et al. (252) demonstrated reduced myocardial oxygen consumption during
the second period of ischemia. Similarly, Tzivoni and
Maybaum (357) have demonstrated a reduction in electrocardiographic evidence of silent ischemia during suc-
Many patients experience brief episodes of ischemia
before an acute MI. It is theoretically possible that this
preinfarct angina has the potential to precondition the
myocardium, thereby reducing infarct size and improving
survival. However, this would be the case only if the
infarct-related artery is reperfused in a timely fashion,
because experimental evidence suggests that ischemic
preconditioning delays necrosis and therefore has no effect on infarction in the territory of a completely occluded
artery in which no reperfusion occurs. It is not surprising
then that studies which evaluated the effects of preinfarct
angina before widespread use of thrombolysis did not
consistently show a beneficial effect in terms of mortality
and left ventricular function (32, 79, 83).
A number of more recent studies evaluated the outcome of patients suffering an acute MI in relation to the
presence of preinfarction angina. For example, Kloner et
al. (179), in a retrospective analysis of the TIMI-4 trial,
showed that the presence of preinfarct angina was associated with smaller infarct size based on peak and total
creatine kinase release, improved left ventricular function
with reduced incidence of congestive heart failure and
shock, and reduced mortality. Similar findings have been
reported by other groups (11, 154, 248, 255). Moreover,
Physiol Rev • VOL
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
animal studies, early evidence suggests that mitoKATP
channels may also be involved in mediating ischemic
preconditioning in the human muscle. In this respect,
Yellon and colleagues (37) have shown that selective
blockade of mitoKATP channels with 5-HD attenuates the
protection by ischemic preconditioning in human atrial
trabeculae. The role of KATP channels in this in vitro
model was also demonstrated in a work by Cleveland et
al. (69) who showed that atrial trabeculae obtained from
diabetic patients on oral hypoglycemic sulfonylureas,
which block KATP channels, could not be protected by
ischemic preconditioning. As mentioned above, other triggers of the preconditioning response such as ␦-opioid
agonists have also been investigated using this human
muscle and have demonstrated a direct protective effect;
more importantly, however, is that this protection appears to be associated with opening of the mitoKATP (37).
Other studies, using sections taken from human right
atrial muscle in which leakage of creatine kinase was
used as an index of injury, have demonstrated that it is
possible to precondition human muscle by both simulated
ischemia as well as pharmacological means and confirm
the importance of the mitoKATP channel in the protection
observed (118). In addition, with the use of the same
model, both an early and a delayed form of preconditioning have also been identified (119).
MYOCARDIAL PRECONDITIONING
Physiol Rev • VOL
based on the known inhibitory effects of adenosine, released during the brief periods of preinfarct ischemia, on
platelet aggregation following activation of A2 receptors
on platelet membranes, which has been suggested to
modify thrombus formation and thereby promote earlier
reperfusion after thrombolysis (8). In this regard, Przyklenk and colleagues (136, 280) have recently demonstrated that in anesthetized open-chest dogs, brief periods
of ischemia before a long ischemic insult attenuates platelet-mediated thrombosis and improves vessel patency and
that this effect was abolished by inhibition of adenosine
receptors.
It must be stated that not all preinfarct angina studies
have yielded positive results. Zahn et al. (411) in a recent
report demonstrated that preinfarct angina had no benefit
when the infarct area was perfused by PTCA rather than
thrombolysis, which may well support the findings of
Andreotti et al. (9).
In addition to the above, there is also debate as well
as controversy as to whether preconditioning occurs in
the elderly patient or indeed if it can be of any benefit
(1–3, 160, 176). Although most of the preclinical experimental data would suggest that preconditioning the aged
animal may present a problem (106, 302) in the clinical
setting, this is not as clear.
3. Angioplasty studies
Coronary angioplasty (PTCA) provides a unique opportunity to study the response of the human myocardium
to brief periods of controlled ischemia and reperfusion.
The procedure usually involves repeated intracoronary
balloon inflations with intervening periods of perfusion,
and in theory the first period of ischemia may enhance the
myocardial tolerance to subsequent balloon inflations via
classic ischemic preconditioning. Several recent studies
have addressed this issue using various indices of myocardial ischemia including clinical, electrocardiographic,
metabolic, and hemodynamic measurements. Most of
these studies, but not all (99), have shown that if the
duration of the first balloon inflation is longer than a
“threshold” of ⬃60 –90 s, all indicators of myocardial ischemia, including chest pain severity, abnormalities of left
ventricular regional wall motion, S-T segment elevation,
Q-T dispersion, ventricular ectopic activity, lactate production, and release of myocardial markers such as
CKMB are attenuated during subsequent balloon inflations, providing evidence for myocardial adaptation induced by the first period of ischemia (4, 80, 92, 103, 253).
As with many studies of ischemic preconditioning in humans, a major confounding factor during successive balloon inflations in PTCA studies is the acute recruitment of
collateral vessels. However, studies that have controlled
for this effect by angiographic grading of the collateral
vessels (80), measurement of cardiac vein flow (92),
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
patients who experience angina before acute MI seem to
have reduced occurrence of life-threatening ventricular
arrhythmias associated with reperfusion (11, 332) and a
lower in-hospital, 1- and 5-year cardiac mortality rate
(153, 178, 179).
Whether the protection conferred to these patients as
a result of their preceding ischemic symptoms represents
a form of myocardial adaptation similar to ischemic preconditioning remains a subject of debate (88). Preconditioning, by virtue of delaying myocardial necrosis and
improving postischemic functional recovery, as seen in
laboratory animals, may contribute to the improved outcome in patients with preinfarct angina. Interestingly,
recent evidence suggests that the time interval between
the last episode of angina and the index MI is very important. Reports from the TIMI-9B investigators (178) and
studies by Ishihara et al. (153) and Yamagishi et al. (389)
indicate that prodromal angina is only protective if it
occurs within 24 –72 h of MI, a time course that closely
resembles that of the delayed phase of myocardial protection following ischemic preconditioning in animal
models.
However, in addition to the possible protection conferred by ischemic preconditioning, infarct size, and the
degree of preservation of postischemic left ventricular
function are determined by a number of other factors
including the extent of collateral circulation to the ischemic myocardium, time from onset of infarction to reperfusion of the infarct-related artery, and residual coronary
stenosis after reperfusion. Studies that have analyzed the
degree of collateralization to the ischemic zone after an
infarction have found no increase in angiographically visible collateral vessels in patients with preinfarct angina
(179, 255). It must be noted, however, that coronary angiography at 90 min after thrombolysis is unlikely to
provide information about the degree of collateral recruitment to the ischemic zone during coronary occlusion, and
it is therefore difficult to rule out a contribution by collateral circulation in this setting. Interestingly, in a recent
study (389), resting myocardial-dual isotope SPECT using
123
I-15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid
(123I-BMIPP) and thallium (201Tl) in the subacute phase of
MI was employed to assess the area at risk and necrotic
myocardium, respectively. Yamagishi et al. (389) found
that patients with preinfarct angina had significantly
smaller infarcts compared with those with no preceding
symptoms, in the face of no significant difference in areas
of myocardium at risk, suggesting that the presence of
preinfarction angina did not predict improved collateral
recruitment to the ischemic zone.
Another equally attractive hypothesis, although not
mutually exclusive from the mechanisms underlying ischemic preconditioning, is facilitation of more rapid reperfusion of the infarct-related artery following thrombolysis
in patients with preinfarct angina (9). This hypothesis is
1135
1136
DEREK M. YELLON AND JAMES M. DOWNEY
nels in mediating this form of adaptation (see Fig. 6). This
finding is supported by the observation that opening of
these channels with nicorandil reduces the electrocardiographic indices of ischemia during coronary angioplasty
(288). Furthermore, an important role has been demonstrated for adenosine in mediating myocardial adaptation
during coronary angioplasty (195). Inhibition of adenosine receptors by bamiphylline (347) or aminophylline
(66) abolishes myocardial adaptation during the second
balloon inflation. Conversely, intracoronary infusion of
adenosine before PTCA, independent of its vasodilatory
effect, attenuates ischemic indices during the first balloon
inflation (195). Two other reports have suggested a role
for both opioid (349) and bradykinin (197) receptors in
mediating myocardial adaptation during PTCA. These
studies provide further evidence that myocardial tolerance to further ischemic episodes can be induced by
FIG. 6. S-T segment shift at the end of each of
two 120-s serial balloon inflations in a patient’s coronary artery. Note that the S-T segment voltage is
much lower in the second inflation in the placebo
patients, indicating ischemic preconditioning. Blocking KATP channels with glibenclamide eliminates this
response. Top panels shows voltage measured from a
surface electrocardiogram (ECG), while the bottom
panels record that from within the coronary artery
via the guide wire. [From Tomai et al. (346).]
Physiol Rev • VOL
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
changes in blood flow velocity in the contralateral coronary artery (348), and more accurately, by assessment of
intracoronary pressure derived-collateral flow index during successive balloon inflations (40), have shown that
although collateral recruitment occurs in some patients, it
cannot fully explain the myocardial adaptation observed
during repeated balloon inflations. Furthermore, some
would argue that collateral flow recruitment in the setting
of coronary angioplasty does not make a major contribution to myocardial protection in this setting (218).
Investigation into the mechanisms underlying this
rapid protection of the myocardium during PTCA has
provided further support for a preconditioning-like effect.
Tomai et al. (346) reported that blockade of KATP channels with oral glibenclamide before angioplasty abolishes
the reduction in ischemic indices observed during subsequent balloon inflations, implying a role for these chan-
MYOCARDIAL PRECONDITIONING
4. Surgical studies
Possibly the most direct evidence for preconditioning in humans comes from studies that have examined
whether a specified preconditioning protocol can protect
the human myocardium from the period of global ischemia induced by aortic cross-clamping during coronary
artery bypass grafting. In this respect, Yellon et al. (403)
were the first to report a prospective study examining the
Physiol Rev • VOL
effects of a preconditioning protocol of two cycles of 3
min of global ischemia (induced by intermittent crossclamping the aorta and pacing the heart at 90 beats/min)
followed by 2 min of reperfusion before a 10-min period of
global ischemia and ventricular fibrillation. Changes in
ATP content from needle biopsies of left ventricular muscle were used as the end point in this study. It was found
that patients subjected to this preconditioning protocol
had better preservation of ATP levels during the subsequent global ischemic period. These findings were almost
identical to those observed in canine hearts by Murry et
al. (241). The preconditioned dogs showing this relative
preservation of ATP during the early stages of prolonged
ischemia sustained significantly smaller infarcts at the
end of 40-min ischemia. Myocardial necrosis was not
estimated in that original human study; however, in a
more recent study (157), serum levels of troponin T were
used as an indicator of myocardial cell necrosis in the
same model (see Fig. 7). With the use of this end point, it
was shown that patients subjected to the preconditioning
protocol suffered significantly less myocardial necrosis
during the 10-min period of global ischemia. This study
has recently been repeated and similar results obtained
with ischemic preconditioning (338). In an earlier study,
cardioplegic arrest was used as opposed to cross-clamp
fibrillation. A preconditioning protocol of 1 min of aortic
cross-clamping followed by 5 min of reperfusion immediately before the cardioplegic arrest resulted in a significant improvement in postoperative cardiac index and
reduced requirement for inotropic support compared
with the nonpreconditioned group (150). In addition to
the above, there have been some studies that have compared the use of ischemic preconditioning with that of
pharmacological preconditioning with mixed results. In
this regard, using troponin I release as an index of injury,
it has been shown that preconditioning with a 5-min infusion of adenosine, followed by 10-min washout, failed
to demonstrate any protection compared with control
(34). More recently, Yellon’s group (338) has shown that
an adenosine A1 receptor agonist, GR79123x, although
statistically unable to demonstrate protection compared
with preconditioning with ischemia, did appear to offer
some benefit. As discussed in section IIC, it is known that
to precondition the myocardium a certain threshold of
stimulation has to be reached to elicit the preconditioning
response (122, 236). In addition, as discussed above, the
duration of ischemia required to elicit preconditioning is
known to vary between species (192). Thus it could be
argued that the dose of both the adenosine (34) and
GR79236x (338) used may have been insufficient to reach
the threshold to trigger the myocardial preconditioning
signaling pathway in humans. Another possible explanation is that stimulation of the adenosine A1 receptor alone
is inadequate to precondition the human heart in this
setting. Evidence exists for a role for both the adenosine
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
preceding brief periods of ischemia and that this tolerance may be mediated by the same mechanisms as those
involved in ischemic preconditioning in animal models.
With respect to the SWOP, very little information is available as to whether pharmacological protection can be
seen in humans. Leesar et al. (196) were the first to report
that a delayed protective effect could be seen in patients
undergoing angioplasty using nitroglycerin and suggest
that prophylactic administration could be a novel approach to protection of the ischemic myocardium in such
patients. However, the potential development of tolerance seen with this type of agent may preclude its prophylactic use (139).
However, recent experimental evidence has provided
grounds for caution when interpreting the results of these
PTCA studies, which have mostly employed S-T segment
elevation on the surface or intracoronary electrocardiogram as an end point reflecting the degree of myocardial
ischemia, and its attenuation during successive balloon
inflations as an indicator of enhanced myocardial resistance to ischemia. Although this assumption was supported by earlier experimental studies of repeated coronary artery occlusion in collateral-deficient pig and rabbit
hearts (74, 308), a study by Downey’s group (41) clearly
indicates a dissociation between S-T segment changes on
the electrocardiogram and myocardial protection in terms
of infarct limitation. Their finding, that the changes in S-T
segment voltage during coronary artery occlusion may
merely represent an epiphenomenon distinct from the
cardioprotective effect of ischemic preconditioning, is
particularly pertinent when evaluating or designing mechanistic studies using pharmacological agents to mimic or
abolish the cellular signaling mechanisms of ischemic
preconditioning. It is imperative that the influence of
these pharmacological tools on the sarcolemmal KATP
channels, thought to modulate electrocardiogram voltages, is clearly distinguished from their effect on the
mitoKATP channels, which have been proposed as a mediator of cardioprotection (297).
As with preconditioning in elderly patients in the
setting of warm-up angina, Lee et al. (194) noted that in
the setting of angioplasty there also appeared to be impaired preconditioning responses in elderly compared
with adult patients that was related to ATP-sensitive potassium channels.
1137
1138
DEREK M. YELLON AND JAMES M. DOWNEY
FIG. 7. Ischemic preconditioning prevents troponin T
release in surgical patients undergoing coronary artery
bypass grafting (CABG). Preconditioning was induced by
two 3-min periods of aortic cross clamping with 2-min
intervening reperfusion. Dramatic protection against ischemic injury is indicated by reduced troponin T release.
[Modified from Jenkins et al. (157).]
Physiol Rev • VOL
ever, this hypothesis is not supported by recent studies
that indicate improved myocardial preservation by ischemic preconditioning during coronary bypass or valve
surgery despite optimal protection with hypothermia and
cardioplegia (150, 198). Finally, in the most recent study
(337), comparing ischemic preconditioning with two established methods of myocardial protection in patients
undergoing CABG, namely, cold crystalloid cardioplegia
and intermittent cross-clamp fibrillation, it was found that
ischemic preconditioning appeared to be superior to limiting myocardial necrosis during CABG, but there was no
difference between cold crystalloid cardioplegia and intermittent cross-clamp fibrillation. Resolution of all these discrepancies is obviously required before brief antecedent
ischemia or pharmacological agents that mimic this effect
can be advocated as a means of prophylactic therapy.
C. Therapeutic Implications
It can be deduced from the evidence outlined above
that the human myocardium is amenable to preconditioning and also that preconditioning occurs as a natural
feature of some ischemic syndromes. Two important
questions arise regarding the applicability of ischemic
preconditioning that need careful consideration. First, are
there areas in clinical medicine in which therapeutic preconditioning may be utilized to benefit patients with ischemic heart disease? Second, can the naturally occurring
preconditioning that follows ischemic syndromes such as
angina be exploited, and does treating the symptoms of
angina abolish any possible cardioprotective effects?
Early revascularization strategies remain the most
effective means of limiting ischemic injury. The time in-
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
A1 and A3 receptors in protection of both isolated rabbit
as well as isolated human atrial muscle against simulated
ischemia. (57, 204). As such, stimulation of both A1 and A3
adenosine receptors may be required to precondition the
human heart in vivo.
In addition to the above, it could also be argued that
many drugs used during cardiac surgery are noted to have
preconditioning properties in the laboratory setting. In
this regard, isoflurane has been shown to have beneficial
effects during coronary artery bypass surgery (using troponin I release as an index of injury) (351). Isoflurane
itself has also been used to directly precondition the
myocardium when given as a preconditioning stimulus
(34, 77). In addition, it is well known that opioids can
precondition both animal and human muscle (37, 202).
Studies that have used other cardioprotective strategies during the prolonged period of ischemia, such as
hypothermia or cardioplegia, have not consistently demonstrated additional protection by ischemic preconditioning. For instance, Perrault and colleagues (269), using a
similar preconditioning protocol of one 3-min episode of
aortic cross-clamping before the onset of cardioplegic
arrest, failed to show any beneficial effects compared
with the control group; in fact, the preconditioned group
of patients had more creatine kinase release compared
with case-matched controls. Similarly, negative results
have been reported by another group using normothermic
retrograde blood cardioplegia with or without preceding
ischemic preconditioning (167). These divergent results
have led to the hypothesis that in the setting of coronary
artery bypass surgery, the additional protection conferred
by ischemic preconditioning may only be demonstrable
where a potential for suboptimal myocardial protection
increases the risk of perioperative infarction (268). How-
MYOCARDIAL PRECONDITIONING
Physiol Rev • VOL
coronary occlusion, and ⬎10% die or suffer a MI (or
reinfarction) within 6 mo with about one-half of these
events occurring during the acute early phase (402). Thus
this group of patients may be amenable to pharmacological intervention with agents that mimic the preconditioning phenomenon to provide potential “insurance” should
that patient proceed to infarction or to buy time before
instituting some form of reperfusion strategy. In this regard, Patel et al. (264) have shown that opening of KATP
channels with nicorandil, in addition to standard aggressive medical therapy for unstable angina, results in a
significant reduction in the incidence of myocardial ischemic episodes and tachyarrhythmias. This may purely
represent an anti-ischemic effect due to the vasodilatory
properties of nicorandil. However, because the patients in
this study were already on maximal antianginal therapy,
and in particular a significant proportion were treated
with intravenous or oral nitrates, it is possible that the
protection observed in the nicorandil group, be it only
using soft end points of myocardial injury, may at least
partially be due to a preconditioning-like effect (89).
Second, even when prior treatment with the pharmacological preconditioning agent is feasible, the duration of
the protection afforded is limited. The temporal profile of
the protective effects of preconditioning in humans is
unknown, but according to experimental evidence in laboratory animals, it is unlikely to exceed 48 –72 h (26, 334).
Therefore, unless the onset of an ischemic event can be
predicted with accuracy, repeated dosing with the potential preconditioning drug will be necessary in these highrisk patients to maintain the preconditioned state. Early
experimental evidence suggested that the protective effects of “classic” ischemic preconditioning is lost after
prolonged periods of repetitive ischemia (73), or chronic
pharmacological preconditioning with selective adenosine A1 agonists (355). However, encouraging evidence
indicates that tachyphylaxis could be overcome by exploiting the prolonged time course of the SWOP. Intermittent treatment of conscious rabbits with an optimal dosing regimen of pharmacological preconditioning with selective adenosine A1 receptor agonists maintains the
animals in a preconditioned state over a period of several
days and results in a significant reduction in infarct size
(84).
Preconditioning strategies might also be applied before planned procedures that involve a potentially injurious ischemic insult such as coronary artery bypass surgery or angioplasty. Highly effective methods of myocardial protection during coronary artery surgery have been
developed including chemical cardioplegia, hypothermia,
and cross-clamp ventricular fibrillation. However, with
increasing number of operations on older and higher risk
patients, there is always a need for improved protection.
Therapies that stimulate preconditioning mechanisms, administered before such operations, have the potential to
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
terval between the onset of symptoms and initiation of
revascularization is however crucial, and the benefits of
treatment diminish as this interval increases (341). Preconditioning, by virtue of delaying myocardial necrosis,
prolongs the time window during which revascularization
therapies can be administered. However, the use of brief
antecedent ischemia as a means of prophylactic induction
of this protection is not desirable or feasible in most
circumstances. On the other hand, the use of pharmacological agents capable of mimicking the protective effects
of preconditioning, in lieu of brief ischemia, may provide
a more benign approach for eliciting cardioprotection.
Potential candidates currently in clinical use include
adenosine or its analogs and KATP channel openers such
as nicorandil. It is crucial to appreciate however that such
strategies require pretreatment; the myocardium must be
preconditioned before the onset of lethal ischemia. Of
recent interest in this respect are the results from the
IONA study (339). This study was the first outcome study
in stable angina which reported that patients pretreated
with the KATP channel opener nicorandil had an improved
outcome due a reduction in major coronary events. Although the trial design does not permit any conclusions as
to the precise mechanism through which the beneficial
effects were seen, the authors suggest that the most plausible explanation is that nicorandil acts as pharmacological mimetic of the preconditioning phenomenon.
Whether this agent is the first clinically available
preconditioning mimetic or not, it is clear that our understanding of the potential mechanisms associated with the
preconditioning phenomenon has allowed agents such as
nicorandil, a known mitoKATP channel opener (296), to be
examined in the clinical setting. It is also possible that
other drugs that potentiate preconditioning triggers such
as ACE inhibitors could also have influenced the clinical
outcome from some of the trials such as HOPE (410).
The acute coronary syndromes (ACS) comprise a
spectrum of pathophysiological conditions spanning unstable angina, non-S-T elevation MI and acute S-T elevation MI. In patients with acute MI with persistent S-T
elevation, early reperfusion to reestablish epicardial
blood flow is well established as the standard of care, be
it with early fibrinolytic therapy, or where the facilities
and expertise are available, to undertake primary angioplasty (353). As far as pharmacological preconditioning
strategies are concerned, these patients are unlikely to
benefit from such treatment, and their management
should focus on early restoration of coronary artery patency and potential strategies to minimize reperfusion
injury (405). On the other hand, non-S-T elevation ACS,
including unstable angina and non-Q-wave MI, mark the
transition from stable coronary artery disease to an unstable state and constitute the leading cause of hospital
admission in patients with coronary artery disease. This
group of patients is at a high risk of progression to acute
1139
1140
DEREK M. YELLON AND JAMES M. DOWNEY
Physiol Rev • VOL
vents ischemic preconditioning during coronary angioplasty (66, 348) and in human atrial trabeculae (371)
questions the use of agents such as methylxanthines in
high-risk patients such as those with unstable angina or
those undergoing revascularization procedures.
D. Summary
A wealth of evidence supports the concept that ischemic preconditioning profoundly and consistently limits
infarct size in the experimental laboratory. Several lines
of evidence obtained from human myocardial tissue, from
the catheterization laboratory and the operating theater,
and from analyses of large clinical trials suggest that the
human myocardium may behave in a similar way. There
are several classes of pharmacological agents that may be
able to mimic the protection conferred by ischemic preconditioning and provide some basis for optimism that a
beneficial and clinically detectable improvement in myocardial protection may be possible. In the short term,
further studies in routine (low-risk) patients must be performed to establish the safety of these agents using multiple end points to detect small differences in myocardial
viability and extent of micronecrosis. In the longer term
however, large-scale studies involving high-risk patients
are warranted to investigate the potential cardioprotective effects of these agents with comparisons against
preexisting myocardial protective strategies. With a more
complete understanding of the mechanisms underlying
myocardial adaptation, we can look forward to development of new therapeutic agents with novel mechanisms of
action to supplement the current treatment options for
patients with ischemic heart disease.
VI. CONCLUSION AND PERSPECTIVES
In conclusion, the phenomenon of ischemic preconditioning has shown us that cardioprotection is indeed
possible. The exquisite adaptive behavior of the cell in
protecting itself from severe ischemic stress is truly remarkable. Over the last two decades there has been a
concerted effort of trying to understand the mechanism of
this adaptive phenomenon. Clearly significant inroads
have and are continuing to be made into the mechanism
of this phenomenon. This review has tried to put in context the enormous research effort that has taken place
over the last two decades; however, we must not be
complacent and must continue until a complete understanding of the preconditioning phenomenon has been
achieved.
We are grateful to all our students, research fellows, and
colleagues who contributed to studies from our laboratories that
are quoted in this review.
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
provide this increased protection. For instance, adenosine, an important mediator of the preconditioning phenomenon in human atrial trabeculae (371) and during
coronary angioplasty (195), has been shown to result in
improved postoperative left ventricular function when
administered intravenously before cardiopulmonary bypass (193). Similarly, although routine PTCA carries a
small risk (⬍5%) of complete coronary occlusion and MI,
high-risk patients undergoing PTCA might benefit from
pretreatment with agents that mimic preconditioning or
augment the protection afforded by the first balloon inflation. In this respect, a recent study by Sakai et al. (289)
has demonstrated that an intracoronary infusion with the
nicorandil prior to PTCA resulted in enhanced tolerance
to subsequent prolonged balloon inflations. The possibility that organ preservation before transplantation might
be amenable to the same improved protection, as suggested by some experimental evidence (164a, 166, 190), is
also of significant interest. This might allow an extension
of the “cold ischemic time” between harvesting and implantation, facilitating optimal matching of recipient to
donor, as well as affording a potential improvement in
early myocardial function.
In response to the second question of whether angina
induces preconditioning and if treating the symptoms of
angina abolish this protection, the evidence must be
viewed with caution. It must be emphasized that extension of the evidence reviewed above in favor of preconditioning to routine clinical practice is speculative at this
stage. However, considering the current evidence for the
mechanisms underlying myocardial adaptation, we can
question the choice of drug treatment for patients with
angina. For example, the probable involvement of KATP
channels as protein mediating the cardioprotective effects of preconditioning favors the use of the KATP channel openers such as nicorandil. Conversely, the increased
mortality from ischemic heart disease observed in diabetic patients on certain oral hypoglycemic therapy begs
a radical review of drug treatment of diabetic patients
with angina (104), since sulfonylureas, the most widely
used oral hypoglycemic agents, block KATP channels and
the possible cardioprotective effects of ischemic preconditioning. In this regard, it has recently been shown that
not all sulfonylureas appear to behave in the same way
with respect to preconditioning. Using an isolated perfused rat heart model, Yellon and colleagues (234) were
able to demonstrate that glibenclamide blocked the protective effect of preconditioning; this effect was directly
attributable to the mitoKATP channel, whereas a newer
sulfonylurea, glimeperide, with less cardiovascular specificity, was unable to block the protection or effect the
mitoKATP channel. Such studies may have important implications for the treatment of type II diabetic patients
with ongoing ischemic heart disease. Similarly, the demonstration that antagonism of adenosine receptors pre-
MYOCARDIAL PRECONDITIONING
The Yellon laboratory has been funded by the British Heart
Foundation, the Wellcome Trust, and University College London. Work in the Downey laboratory has been funded by the
National Institutes of Health, Heart Lung Institute.
Address for reprint requests and other correspondence:
D. M. Yellon, The Hatter Institute for Cardiovascular Studies,
Centre for Cardiology, University College London Hospital and
Medical School, Grafton Way, London WC1E 6DB, UK (E-mail:
[email protected]).
REFERENCES
Physiol Rev • VOL
receptors with N6-(3-iodobenzyl) adenosine-5⬘-N-methyluronamide
protects against myocardial stunning and infarction without hemodynamic changes in conscious rabbits. Circ Res 80: 800 – 809, 1997.
17. Baines CP, Goto M, and Downey JM. Oxygen radicals released
during ischemic preconditioning contribute to cardioprotection in
the rabbit myocardium. J Mol Cell Cardiol 29: 207–216, 1997.
18. Baines CP, Liu GS, Birincioglu M, Critz SD, Cohen MV, and
Downey JM. Ischemic preconditioning depends on interaction
between mitochondrial KATP channels and actin cytoskeleton.
Am J Physiol Heart Circ Physiol 276: H1361–H1368, 1999.
19. Baines CP, Pass JM, and Ping P. Protein kinases and kinase
modulated effectors in the late phase of ischemic preconditioning.
Basic Res Cardiol 96: 207–218, 2001.
20. Baines CP, Wang L, Cohen MV, and Downey JM. Protein tyrosine kinase is downstream of protein kinase C for ischemic
preconditioning’s anti-infarct effect in the rabbit heart. J Mol Cell
Cardiol 30: 383–392, 1998.
21. Baines CP, Zhang J, Wang GW, Zheng YT, Xiu JX, Cardwell
EM, Bolli R, and Ping P. Mitochondrial PKCepsilon and MAPK
form signaling modules in the murine heart: enhanced mitochondrial PKCepsilon-MAPK interactions and differential MAPK activation in PKCepsilon-induced cardioprotection. Circ Res 90: 390 –397,
2002.
22. Banerjee A, Locke-Winter C, Rogers KB, Mitchell MB, Brew
EC, Cairns CB, Bensard DD, and Harken AH. Preconditioning
against myocardial dysfunction after ischemia and reperfusion by
an ␣1-adrenergic mechanism. Circ Res 73: 656 – 670, 1993.
23. Barancik M, Htun P, and Schaper W. Okadaic acid and anisomycin are protective and stimulate the SAPK/JNK pathway. J Cardiovasc Pharmacol 34: 182–190, 1999.
24. Barancik M, Htun P, Strohm C, Kilian S, and Schaper W.
Inhibition of the cardiac p38-MAPK pathway by SB203580 delays
ischemic cell death. J Cardiovasc Pharmacol 35: 474 – 483, 2000.
24a.Barbosa V, Sievers RE, Zaugg CE, and Wolf CL. Preconditioning ischemia time determines the degree of glycogen depletion and
infarct size reduction in rat hearts. Am Heart J 131: 224 –230, 1996.
25. Baxter GF, Goma FM, and Yellon DM. Involvement of protein
kinase C in the delayed cytoprotection following sublethal ischaemia in rabbit myocardium. Br J Pharmacol 115: 222–224, 1995.
26. Baxter GF, Goma FM, and Yellon DM. Characterisation of the
infarct-limiting effect of delayed preconditioning: time course and
dose-dependency studies in rabbit myocardium. Basic Res Cardiol
92: 159 –167, 1997.
27. Baxter GF, Marber MS, Patel VC, and Yellon DM. Adenosine
receptor involvement in a delayed phase of myocardial protection
24 hours after ischemic preconditioning. Circulation 90: 2993–
3000, 1994.
28. Baxter GF, Mocanu MM, and Yellon DM. Attenuation of myocardial ischaemic injury 24 h after diacylglycerol treatment in vivo.
J Mol Cell Cardiol 29: 1967–1975, 1997.
29. Baxter GF and Yellon DM. Time course of delayed myocardial
protection after transient A1 receptor activation in the rabbit.
J Cardiovasc Pharmacol 29: 631– 638, 1997.
30. Baxter GF and Yellon DM. ATP-sensitive K⫹ channels mediate
the delayed cardioprotective effect of adenosine A1 receptor activation. J Mol Cell Cardiol 31: 981–989, 1999.
31. Becker LB, Vanden Hoek TL, Shao Z-H, Li C-Q, and Schumacker PT. Generation of superoxide in cardiomyocytes during
ischemia before reperfusion. Am J Physiol Heart Circ Physiol 277:
H2240 –H2246, 1999.
32. Behar S, Reicher-Reiss H, and Allmader E. The prognostic
significance of angina pectoris preceding the occurrence of a first
myocardial infarction in 4166 consecutive hospilized patients. Am
Heart J 123: 1481–1486, 1992.
33. Behrends M, Schulz R, Post H, Alexandrov A, Belosjorow S,
Michel MC, and Heusch G. Inconsistent relation of MAPK activation to infarct size reduction by ischemic preconditioning in pigs.
Am J Physiol Heart Circ Physiol 279: H1111–H1119, 2000.
34. Belhomme D, Peynet J, Louzy M, Launay J-M, Kitakaze M,
and Menasche P. Evidence for preconditioning by isoflurane in
coronary artery bypass graft surgery. Circulation 100: II-340 –II344, 1999.
35. Bell RM, Smith CC, and Yellon DM. Nitric oxide as a mediator of
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
1. Abete P, Ferrara N, Cacciatore F, Madrid A, Bianco S, Calabrese C, Napoli C, Scognamiglio P, Bollella O, Cioppa A,
Longobardi G, and Rengo F. Angina-induced protection against
myocardial infarction in adult and elderly patients: a loss of preconditioning mechanism in the aging heart? J Am Coll Cardiol 30:
947–954, 1997.
2. Abete P, Ferrara N, Cioppa A, Ferrara P, Bianco S, Cacciatore F, Longobardi G, and Rengo F. Preconditioning does not
prevent postischemic dysfunction in aging heart. Am J Cardiol 27:
1777–1786, 1996.
3. Abete P, Napoli C, and Rengo F. Loss of cardioprotective effects
of preconditioning angina in elderly but not in adult patients. Am J
Cardiol 88: 721, 2002.
4. Airaksinen KE and Huikuri HV. Antiarrhythmic effect of repeated coronary occlusion during balloon angioplasty. J Am Coll
Cardiol 29: 1035, 1997.
5. Alkhulaifi AM, Pugsley WB, and Yellon DM. The influence of
the time period between preconditioning ischemia and prolonged
ischemia on myocardial protection. Cardioscience 4: 163–169,
1993.
6. Allo SN, Bagby L, and Schaffer SW. Taurine depletion, a novel
mechanism for cardioprotection from regional ischemia. Am J
Physiol Heart Circ Physiol 273: H1956 –H1961, 1997.
7. Alonzo A, Darbenzio R, Parham C, and Grover G. Effects of
intracoronary cromakalim on postischaemic contractile function
and action potential duration. Cardiovasc Res 26: 1046 –1053, 1992.
8. Andreotti F and Pasceri V. Ischemic preconditioning. Lancet
348: 204, 1996.
9. Andreotti F, Pasceri V, Hackett DR, Davies GJ, Haider AW,
and Maseri A. Preinfarction angina as a predictor of more rapid
coronary thrombolysis in patients with acute myocardial infarction. N Engl J Med 334: 7–12, 1996.
10. Anversa P, Cheng W, Liu Y, Leri A, Redaelli G, and Kajstura
J. Apoptosis and myocardial infarction. Basic Res Cardiol 93
Suppl 3: 8 –12, 1998.
11. Anzai T, Yoshikawa T, Asakura Y, Abe S, Akaishi M, Mitamura H, Handa S, and Ogawa S. Preinfarction angina as a major
predictor of left ventricular function and long term prognosis after
a first Q wave myocardial infarction. J Am Coll Cardiol 26: 319 –
327, 1995.
12. Armstrong S, Downey JM, and Ganote CE. Preconditioning of
isolated rabbit cardiomyocytes: induction by metabolic stress and
blockade by the adenosine antagonist SPT and calphostin C, a
protein kinase C inhibitor. Cardiovasc Res 28: 72–77, 1994.
13. Armstrong SC, Delacey M, and Ganote CE. Phosphorylation
state of hsp27 and p38 MAPK during preconditioning and protein
phosphatase inhibitor protection of rabbit cardiomyocytes. J Mol
Cell Cardiol 31: 555–567, 1999.
14. Armstrong SC and Ganote CE. Effects of the protein phosphatase inhibitors okadaic acid and calyculin A on metabolically inhibited and ischaemic isolated myocytes. J Mol Cell Cardiol 24:
869 – 884, 1992.
15. Arstall MA, Zhao YZ, Hornberger L, Kennedy SP, Buchholtz
RA, Osathanondh R, and Kelly RA. Human ventricular myocytes
in vitro exhibit early and delayed preconditioning responses to
simulated ischemia. J Mol Cell Cardiol 30: 210 –214, 1998.
16. Auchampach JA, Rizvi A, Qiu Y, Tang X-L, Maldonado C,
Teschner S, and Bolli R. Selective activation of A3 adenosine
1141
1142
36.
37.
38.
39.
40.
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
delayed pharmacological (A1 receptor triggered) preconditioning:
is eNOS masquerading as iNOS? Cardiovasc Res 53: 405– 413, 2002.
Bell RM and Yellon DM. The contribution of endothelial nitric
oxide synthase to early ischaemic preconditioning: the lowering of
the preconditioning threshold. An investigation in eNOS knockout
mice. Cardiovasc Res 52: 274 –280, 2001.
Bell SP, Sack MN, Patel A, Opie LH, and Yellon DM. Delta
opioid receptor stimulation mimics ischemic preconditioning in
human heart muscle. J Am Coll Cardiol 36: 2296 –2302, 2000.
Belosjorow S, Schulz R, Dorge H, Schade FU, and Heusch G.
Endotoxin and ischemic preconditioning: TNF-alpha concentration
and myocardial infarct development in rabbits. Am J Physiol Heart
Circ Physiol 277: H2470 –H2475, 1999.
Bernado NL, D’Angelo M, Okubo S, Joy A, and Kukreja RC.
Delayed ischemic preconditioning is mediated by opening of ATPsensitive potassium channels in rabbit heart. Am J Physiol Heart
Circ Physiol 276: H1323–H1330, 1999.
Billinger M, Fleisch M, Eberli FR, Garachemani A, Meier B,
and Seiler C. Is the development of myocardial tolerance to
repeated ischemia in humans due to preconditioning or to collateral recruitment? J Am Coll Cardiol 33: 1027–1035, 1999.
Birincioglu M, Yang X-M, Critz SD, Cohen MV, and Downey
JM. S-T segment voltage during sequential coronary occlusions is
an unreliable marker of preconditioning. Am J Physiol Heart Circ
Physiol 277: H2435–H2441, 1999.
Bluhm WF, Martin JL, Mestril R, and Dillmann WH. Specific
heat shock proteins protect microtubules during simulated ischemia in cardiac myocytes. Am J Physiol Heart Circ Physiol 275:
H2243–H2249, 1998.
Bogoyevitch M, Gillespie-Brown J, Ketterman A, Fuller S,
Ben-Levy R, Ashworth A, Marshall C, and Sugden P. Stimulation of the stress-activated mitogen-activated protein kinase subfamilies in perfused heart. Circ Res 79: 162–173, 1996.
Bolli R. The late phase of preconditioning. Circ Res 87: 972–983,
2000.
Bolli R, Bhatti ZA, Tang X-L, Qiu Y, Zhang Q, Guo Y, and
Jadoon AK. Evidence that late preconditioning against myocardial
stunning in conscious rabbits is triggered by the generation of nitric
oxide. Circ Res 81: 42–52, 1997.
Bolli R, Dawn B, Tang X-L, Qiu Y, Ping P, Xuan Y-T, Jones WK,
Takano H, Guo Y, and Zhang J. The nitric oxide hypothesis of
late preconditioning. Basic Res Cardiol 93: 325–338, 1998.
Bolli R, Manchikalapudi S, Tang X-L, Takano H, Qiu Y, Guo Y,
Zhang Q, and Jadoon AK. The protective effect of late preconditioning against myocardial stunning in conscious rabbits is mediated by nitric oxide synthase. Circ Res 81: 1094 –1107, 1997.
Bolli R and Marbán E. Molecular and cellular mechanisms of
myocardial stunning. Physiol Rev 79: 609 – 634, 1999.
Bonventre JV. Kidney ischemic preconditioning. Curr Opin
Nephrol Hypertens 11: 43– 48, 2002.
Borsch-Haubold AG, Pasquet S, and Watson SP. Direct inhibition of cyclooxygenase-1 and -2 by the kinase inhibitors SB 203580
and PD 98059: SB 203580 also inhibits thromboxane synthase.
J Biol Chem 273: 28766 –28772, 1998.
Brown JM, Terada LS, Grosso MA, Whitmann GJ, Velasco SE,
Patt A, Harken AH, and Repine JE. Xanthine oxidase produces
hydrogen peroxide which contributes to reperfusion injury of ischemic, isolated, perfused rat hearts. J Clin Invest 81: 1297–1301,
1988.
Burckhartt B, Yang X-M, Tsuchida A, Mullane KM, Downey
JM, and Cohen MV. Acadesine extends the window of protection
afforded by ischaemic preconditioning in conscious rabbits. Cardiovasc Res 29: 653– 657, 1995.
Burns PG, Krukenkamp IB, Caldarone CA, Gaudette GR,
Bukhari EA, and Levitsky S. Does cardiopulmonary bypass
alone elicit myoprotective preconditioning. Circulation 92: 447–
451, 1995.
Camitta MG, Gabel SA, Chulada P, Bradbury JA, Langenbach
R, Zeldin DC, and Murphy E. Cyclooxygenase-1 and -2 knockout
mice demonstrate increased cardiac ischemia/reperfusion injury
but are protected by acute preconditioning. Circulation 104: 2453–
2458, 2001.
Carmitta MGW, Gabel SA, Chulada P, Bradbury JA, LangenPhysiol Rev • VOL
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
67.
68.
69.
70.
71.
72.
73.
74.
bach R, Zeldin DC, and Murphy E. Cylooxygenase 1 and 2
knockout mice demonstrate increased cardiac ischemia/reperfusion injury but are protected by acute preconditioning. Circulation
104: 2453–2458, 2001.
Carr CS, Grover GJ, Pugsley WB, and Yellon DM. Comparison
of the protective effects of a highly selective ATP-sensitive potassium channel opener and ischaemic preconditioning in iolsated
human atrial muscle. Cardiovasc Drugs Ther 11: 473– 478, 1997.
Carr CS, Hill RJ, Masamune H, Kennedy SP, Knight DR,
Tracey WR, and Yellon DM. Evidence for a role for both the
adenosine A1 and A3 receptors in protection of isolated human
atrial muscle against simulated ischaemia. Cardiovasc Res 36: 52–
59, 1997.
Carr CS and Yellon DM. A highly selective ATP-dependent potassium channel opener mimics ischaemic preconditioning protection in isolated human atrium. Med Sci Res 24: 651– 654, 1996.
Carr CS and Yellon DM. Ischaemic preconditioning may abolish
the protection afforded by ATP-sensitive potassium channel openers in isolated human atrial muscle. Basic Res Cardiol 92: 252–260,
1997.
Carroll R, Gant VA, and Yellon DM. Mitochondrial KATP channel
opening protects a human atrial-derived cell line by a mechanism
involving free radical generation. Cardiovasc Res 51: 691–700,
2001.
Cave AC and Hearse DJ. Ischaemic preconditioning and contractile function: studies with normothermic and hypothermic global
ischaemia. J Mol Cell Cardiol 24: 1113–1123, 1992.
Chambers DJ, Baimbridge MV, and Hearse DJ. Free radicals
and cardioplegia: allopurinol and oxypurinol reduce myocardial
injury following ischemic arrest. Ann Thorac Surg 44: 291–297,
1987.
Chandrasekar B, Smith JB, and Freeman GL. Ischemia-reperfusion of rat myocardium activates nuclear factor-KappaB and
induces neutrophil infiltration via lipopolysaccharide-induced CXC
chemokine. Circulation 103: 2296 –2302, 2001.
Charlat ML, O’Neill PG, Egan JM, Abernethy DR, Michael LH,
Myers ML, Roberts R, and Bolli R. Evidence for a pathogenetic
role of xanthine oxidase in the “stunned” myocardium. Am J
Physiol Heart Circ Physiol 252: H566 –H577, 1987.
Chien GL, Wolff RA, Davis RF, and Vanwinkle DM. “Normothermic-range” temperature affects myocardial infarct size. Cardiovasc Res 28: 1014 –1017, 1994.
Claeys MJ, Vrints CJ, Bosmans JM, Conraads VM, and Snoeck
JP. Aminophylline inhibits adaptation to ischaemia during coronary angioplasty. Eur Heart J 17: 539 –544, 1996.
Clerk A, Fuller SJ, Michael A, and Sugden PH. Stimulation of
“stress-regulated” mitogen-activated protein kinases (stress-activated protein kinases/c-Jun N-terminal kinases and p38-mitogenactivated protein kinases) in perfused rat hearts by oxidative and
other stresses. J Biol Chem 273: 7228 –7234, 1998.
Clerk A and Sugden PH. The p38-MAPK inhibitor, SB203580,
inhibits cardiac stress-activated protein kinases/c-Jun N-terminal
kinases (SAPKs/JNKs). FEBS Lett 426: 93–96, 1998.
Cleveland JC, Meldrum DR, Cain BS, Banerjee A, and Harken
AH. Oral sulphonylurea hypoglyccemic agents prevent ischemic
preconditionig in human myocardium. Circulation 96: 29 –32, 1997.
Cleveland JC Jr, Meldrum DR, Rowland RT, Banerjee A, and
Harken AH. Adenosine preconditioning of human myocardium is
dependent upon the ATP-sensitive K⫹ channel. J Mol Cell Cardiol
29: 175–182, 1997.
Cohen MV, Baines CP, and Downey JM. Ischemic preconditioning: from adenosine receptor to KATP channel. Annu Rev Physiol
62: 79 –109, 2000.
Cohen MV, Liu GS, and Downey JM. Preconditioning causes
improved wall motion as well as smaller infarcts after transient
coronary occlusion in rabbits. Circulation 84: 341–349, 1991.
Cohen MV, Yang X-M, and Downey JM. Conscious rabbits become tolerant to multiple episodes of ischemic preconditioning.
Circ Res 74: 998 –1004, 1994.
Cohen MV, Yang X-M, and Downey JM. Attenuation of S-T
segment elevation during repetitive coronary occlusions truly reflects the protection of ischemic preconditioning and is not an
epiphenomenon. Basic Res Cardiol 92: 426 – 434, 1997.
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
41.
DEREK M. YELLON AND JAMES M. DOWNEY
MYOCARDIAL PRECONDITIONING
Physiol Rev • VOL
95.
96.
97.
98.
99.
100.
101.
102.
103.
104.
105.
106.
107.
108.
109.
110.
111.
112.
113.
114.
a cardiac mRNA coding for a protein with migration characteristics
similar to heat-shock/stress protein 71. Circ Res 59: 110 –114, 1986.
Dos Santos P, Kowaltowski AJ, Laclau MN, Seetharaman S,
Paucek P, Boudina S, Tariosse L, and Garlid KD. Mechanisms
by which opening the mitochondrial ATP-sensitive K(⫹) channel
protects the ischemic heart. Am J Physiol Heart Circ Physiol 283:
H284 –H295, 2002.
Downey JM. Free radicals and their involvement during long-term
myocardial ischemia and reperfusion. Annu Rev Physiol 52: 487–
504, 1990.
Downey JM, Hearse DJ, and Yellon DM. The role of xanthine
oxidase during myocardial ischemia in several species including
man. J Mol Cell Cardiol 20 Suppl II: 55– 63, 1988.
Dröge W. Free radicals in the physiological control of cell function. Physiol Rev 82: 47–95, 2002.
Dupouy P, Geschwind H, Pelle G, Apteacr E, Hittinger L, El
Ghalid A, and Dubois-Randej L. Repeated coronary artery occlusions during routine balloon angioplasty do not induce myocardial preconditioning in humans. J Am Coll Cardiol 27: 1374 –1380,
1996.
Eaton P, Awad WI, Miller JIA, Hearse DJ, and Shattock MJ.
Ischemic preconditioning: a potential role for constitutive low
molecular weight stress protein translocation and phosphorylation? J Mol Cell Cardiol 32: 961–971, 2000.
Ebrahim Z, Yellon DM, and Baxter GF. Bradkinin induces delayed cardioprotection in rat heart via a nitric oxide dependent
mechanism. Am J Physiol Heart Circ Physiol 281: H1458 –H1464,
2001.
Edwards G and Weston AH. Katp-fact or artefact? New thoughts
on the mode of action of the potassium channel openers. Cardiovasc Res 28: 735–737, 1994.
Eltchaninoff H, Cribier A, Tron C, Derumeaux G, Koning R,
Hecketsweiller B, and Letac B. Adaptation to myocardial ischemia during coronary angioplasty demonstrated by clinical, electrocardiographic, echocardiographic, and metabolic parameters.
Am Heart J 133: 490 –506, 1997.
Engler RL and Yellon DM. Sulphonylurea KATP blockade in type
II diabetes and preconditioning in cardiovascular disease. Time for
reconsideration. Circulation 95: 2297–2301, 1996.
Eyers PA, Van Den Ijssel P, Quinlan RA, Goedert M, and
Cohen P. Use of a drug-resistant mutant of stress-activated protein
kinase 2a/p38 to validate the in vivo specificity of SB 203580. FEBS
Lett 21: 191–196, 1999.
Fenton RA, Dickson EW, Meyer TE, and Dobson GJ Jr. Aging
reduces the cardioprotective effect of ischemic preconditioning in
the rat heart. J Mol Cell Cardiol 32: 1371–1375, 2000.
Ferrari R, Cargnoni A, Bernocchi P, Pasini E, Curello S,
Ceconi C, and Ruigrok TJ. Metabolic adaptation during a sequence of no-flow and low-flow ischemia. A possible trigger for
hibernation. Circulation 94: 2587–2596, 1996.
Forbes RA, Steenbergen C, and Murphy E. Diazoxide-induced
cardioprotection requires signaling through a redox-sensitive
mechanism. Circ Res 88: 802– 809, 2001.
Fryer RM, Hsu AK, Eells JT, Nagase H, and Gross GJ. Opioidinduced second window of cardioprotection: potential role of mitochondrial KATP channels. Circ Res 84: 846 – 851, 1999.
Fryer RM, Hsu AK, and Gross GJ. Erk and p38MAP kinase
activation are components of opioid induced delayed cardioprotection. Basic Res Cardiol 96: 136 –142, 2001.
Fryer RM, Schultz JEJ, Hsu AK, and Gross GJ. Importance of
PKC and tyrosine kinase in single or multiple cycles of preconditioning in rat hearts. Am J Physiol Heart Circ Physiol 276: H1229 –
H1235, 1999.
Ganote CE and Vander Heide RS. Cytoskeletal lesions in anoxic
myocardial injury: a conventional and high voltage electron microscopic and immunofluorescence study. Am J Pathol 129: 327–344,
1987.
Garcia-Dorado D, Ruiz-Meana M, Padilla F, Rjodriguez-Sinovas A, and Mirabet M. Gap-junction mediated intercellular communication in ischemic preconditioning. Cardiovasc Res 55: 456 –
465, 2002.
Garlid KD. Opening mitochondrial KATP in the heart: what hap-
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
75. Cohen MV, Yang X-M, Liu GS, Heusch G, and Downey JM.
Acetylcholine, bradykinin, opioids, and phenylephrine, but not
adenosine, trigger preconditioning by generating free radicals and
opening mitochondrial KATP channels. Circ Res 89: 273–278, 2001.
76. Cohen MV, Yang X-M, Neumann T, Heusch G, and Downey JM.
Favorable remodeling enhances recovery of regional myocardial
function in the weeks after infarction in ischemically preconditioned hearts. Circulation 102: 579 –583, 2000.
77. Cope DK, Impastato WK, Cohen MV, and Downey JM. Volatile
anesthetics protect the ischemic rabbit myocardium from infarction. Anesthesiology 86: 699 –709, 1997.
78. Correa SD and Schlaefer S. Blockade of KATP channels with
glibenclamide does not abolish preconditioning during demand
ischemia. Am J Cardiol 79: 75–78, 1997.
79. Cortina A, Ambrose JA, Prieto-Granada J, Morris C, Simarro
E, Holt J, and Fuster V. Left ventruicular function after myocardial infarction: clinical and angiographic correlations. J Am Coll
Cardiol 5: 619 – 624, 1985.
80. Cribier A, Korsatz L, Koning R, Rath P, Gamra H, Stix G,
Merchant S, Chan C, and Letac B. Improved myocardial ischemic response and enhanced collateral circulation with long repetitive coronary occlusion during angioplasty: a prospective study.
J Am Coll Cardiol 20: 578 –586, 1992.
81. Cuenda A, Rouse J, Doza YN, Meier R, Cohen P, Gallagher TF,
Young PR, and Lee JC. Sb 203580 is a specific inhibitor of a MAP
kinase homologue which is stimulated by cellular stresses and
interleukin-1. FEBS Lett 364: 229 –233, 1995.
82. Cumming DVE, Heads RJ, Brand NJ, Yellon DM, and Latchman DS. The ability of heat stress and metabolic preconditioning
to protect primary rat cardiac myocytes. Basic Res Cardiol 91:
79 – 85, 1996.
83. Cupples LA, Gagnon DR, Wong ND, Ostfeld AM, and Kannel
WB. Pre-existing cardiovascular conditions and long term prognosis after initial myocardial infarction: the Framingham study. Am
Heart J 125: 863– 872, 1993.
84. Dana A, Baxter GF, Walker JM, and Yellon DM. Prolonging the
delayed phase of myocardial protection: repetitive adenosine A1
receptor activation maintains rabbit myocardium in a preconditioned state. J Am Coll Cardiol 31: 1142–1149, 1998.
85. Dana A, Baxter GF, and Yellon DM. Delayed or second window
preconditioning induced by adenosine A1 receptor activation is
independant of early generation of nitric oxide or late induction of
inducible nitric oxide synthase. J Cardiovasc Pharmacol 38: 278 –
287, 2001.
86. Dana A, Jonassen AK, Yamashita N, and Yellon DM. Adenosine
A1 receptor activation induces delayed preconditioning in rats
mediated by manganese superoxide dismutase. Circulation 101:
2841–2848, 2000.
87. Dana A, Skarli M, Papakrivopoulou J, and Yellon DM. Adenosine A1 receptor induced delayed preconditioning in rabbits: induction of p38 mitogen-activated protein kinase activation and
Hsp27 phosphorylation via a tyrosine kinase- and protein kinase
C-dependent mechanism. Circ Res 86: 989 –997, 2000.
88. Dana A and Yellon DM. Cardioprotection by preinfarct angina: is
it ischaemic preconditioning? Eur Heart J 19: 367–369, 1998.
89. Dana A and Yellon DM. ATP dependant K channel: a novel
therapeutic target in unstable angina. Eur Heart J 20: 5, 1999.
90. Datta SR, Brunet A, and Greenburg ME. Cellular survival: a play
in three Akts. Genes Dev 13: 2905–2927, 1999.
91. Dawn B, Xuan Y-T, Qiu Y, Takano H, Tang X-L, Ping P, Banerjee S, Hill M, and Bolli R. Bifunctional role of protein tyrosine
kinases in late preconditioning against myocardial stunning in conscious rabbits. Circ Res 85: 1163, 1999.
92. Deutsch E, Berger M, Kussmaul WG, Hirshfeld JW Jr, Herrmann HC, and Laskey WK. Adaptation to ischemia during percutaneous transluminal coronary angioplasty: clinical, hemodynamic,
and metabolic features. Circulation 82: 2044 –2051, 1990.
93. Diaz RJ, Losito VA, Mao GD, Ford MK, Backx PH, and Wilson
GJ. Chloride channel inhibition blocks the protection of ischemic
preconditioning and hypo-osmotic stress in rabbit ventricular myocardium. Circ Res 84: 763–775, 1999.
94. Dillmann WH, Mehta HB, Barrieux A, Guth BD, Neely WE,
and Ross JJ. Ischemia of the dog heart induces the appearance of
1143
1144
115.
116.
117.
118.
120.
121.
122.
123.
124.
125.
126.
127.
128.
129.
130.
131.
132.
133.
134.
pens, and what does not happen. Basic Res Cardiol 95: 275–279,
2000.
Garlid KD, Paucek P, Yarov-Yarovoy V, Murray HN, Darbenzio RB, D’Alonzo AJ, Lodge NJ, Smith MA, and Grover GJ.
Cardioprotective effect of diazoxide and its interaction with mitochondrial ATP-sensitive K⫹ channels: possible mechanism of cardioprotection. Circ Res 81: 1072–1082, 1997.
Garlid KD, Paucek P, Yarov-Yarovoy V, Sun X, and Schindler
PA. The mitochondrial KATP channel as a receptor for potassium
channel openers. J Biol Chem 271: 8796 – 8799, 1996.
Gelpi RJ, Morales C, Cohen MV, and Downey JM. Xanthine
oxidase contributes to preconditioning’s preservation of left ventricular developed pressure in isolated rat heart: developed pressure may not be an appropriate end-point for studies of preconditioning. Basic Res Cardiol 97: 40 – 46, 2002.
Ghosh S, Standen N, and Galiñanes M. Evidence for mitochondrial KATP channels as effectors of human myocardial preconditioning. Cardiovasc Res 45: 934 –940, 2000.
Ghosh S, Standen N, and Galiñanes M. Preconditioning the
human myocardium by simulated ischemia: studies on the early
and delayed protection. Cardiovasc Res 45: 339 –350, 2000.
Gopalakrishna R and Anderson WB. Ca2⫹ and phospholipidindependent activation of protein kinase C by selective oxidative
modification of the regulatory domain. Proc Natl Acad Sci USA 86:
6758 – 6762, 1989.
Goto M, Cohen MV, Van Wylen DGL, and Downey JM. Attenuated purine production during subsequent ischemia in preconditioned rabbit myocardium is unrelated to the mechanism of protection. J Mol Cell Cardiol 28: 447– 454, 1996.
Goto M, Liu Y, Yang X-M, Ardell JL, Cohen MV, and Downey
JM. Role of bradykinin in protection of ischemic preconditioning
in rabbit hearts. Circ Res 77: 611– 621, 1995.
Gottlieb RA, Burleson KO, Kloner RA, Babior BM, and Engler
RL. Reperfusion injury induces apoptosis in rabbit cardiomyocytes. J Clin Invest 94: 1621–1628, 1994.
Gou Y, Bao W, Wu W-J, Shinmura K, Tang X-L, and Bolli R.
Evidence for an essential role of cyclooxygenase-2 as a mediator of
the late phase of ischaemic preconditioning in mice. Basic Res
Cardiol 95: 479 – 484, 2000.
Gray MO, Karliner JS, and Mochly-Rosen D. A selective ⑀-protein kinase C antagonist inhibits protection of cardiac myocytes
from hypoxia-induced cell death. J Biol Chem 272: 30945–30951,
1997.
Gres P, Heusch G, Skyschally A, and Schulz R. Activation of
ATP-dependent potassium channels is trigger but not mediator of
ischemic preconditioning in pigs (Abstract). Circulation 106: II265, 2002.
Gres P, Schulz R, Jansen J, Umschlag C, and Heusch G. Involvement of endogenous prostaglandins in ischemic preconditioning in pigs. Cardiovasc Res 55: 626 – 632, 2002.
Griffiths EJ and Halestrap AP. Protection by cyclosporin A of
ischemia/reperfusion-induced damage in isolated rat hearts. J Mol
Cell Cardiol 25: 1461–1469, 1993.
Gross GJ and Auchampach JA. Blockade of ATP-sensitive potassium channels prevents myocardial preconditioning in dogs.
Circ Res 70: 223–233, 1992.
Gross GJ and Fryer RM. Sarcolemmal versus mitochondrial ATPsensitive K⫹ channels and myocardial preconditioning. Circ Res 84:
973–979, 1999.
Grover GJ, Sleph PG, and Dzwonczyk S. Role of myocardial
ATP-sensitive potassium channels in mediating preconditioning in
the dog heart and their possible interaction with adenosine A1receptors. Circulation 86: 1310 –1316, 1992.
Guay J, Lambert H, Gingras-Breton G, Lavoie JN, Huot J, and
Landry J. Regulation of actin filament dynamics by p38 map
kinase-mediated phosphorylation of heat shock protein 27. J Cell
Sci 110: 357–368, 1997.
Guo Y, Jones WK, Xuan Y-T,Tang X-L, Bao W, Wu W-J, Han H,
Laubach V, Ping P, Yang Z, Qiu Y, and Bolli R. The late phase of
ischemic preconditioning is abrogated by targeted disruption of the
inducible NO synthase gene. Proc Natl Acad Sci USA 99: 11507–
11512, 1999.
Guo Y, Wu W-J, Qiu Y, Tang X-L, Yang Z, and Bolli R. DemonPhysiol Rev • VOL
135.
136.
137.
138.
139.
140.
141.
142.
143.
144.
145.
146.
147.
148.
149.
150.
151.
152.
153.
stration of an early and a late phase of ischemic preconditioning in
mice. Am J Physiol Heart Circ Physiol 275: H1375–H1387, 1998.
Halestrap AP, Kerr PM, Javadov S, and Woodfield KY. Elucidating the molecular mechanism of the permeability transition
pore and its role in reperfusion injury of the heart. Biochim Biophys Acta 1366: 79 –94, 1998.
Hata K, Whittaker P, Kloner RA, and Przyklenk K. Brief antecedent ischemia attenuates platelet-mediated thrombosis in damaged and stenotic canine coronary arteries: role of adenosine.
Circulation 97: 692–702, 1998.
Hausenloy DJ, Maddock HL, Baxter GF, and Yellon DM. Inhibiting mitochondrial permeability transition pore opening: a new
paradigm in myocardial preconditioning. Cardiovasc Res 55: 534 –
543, 2002.
Heads RJ, Latchman DS, and Yellon DM. Stable high level
expression of a transfected human HSP70 gene protects a heartderived muscle cell line against thermal stress. J Mol Cell Cardiol
26: 695– 699, 1994.
Heusch G. Nitroglycerin and delayed preconditioning in humans:
yet another new mechanism for an old drug? Circulation 103:
2876 –2878, 2001.
Heusch G, Liu GS, Rose J, Cohen MV, and Downey JM. No
confirmation for a causal role of volume-regulated chloride channels in ischemic preconditioning in rabbits. J Mol Cell Cardiol 32:
2279 –2285, 2000.
Holly T, Nakamura S, Yaroshenko Y, Decker RS, Decker ML,
Harris KR, and Klocke FJ. Ischemic preconditioning causes
translocation of constitutive ␣B-crystallin and HSP27 to myofibrils
and/or the cytoskeleton in rabbits (Abstract). FASEB J 13: A1065,
1999.
Holly TA, Drincic A, Byun Y, Nakamura S, Harris K, Klocke
FJ, and Cryns VL. Caspase inhibition reduces myocyte cell death
induced by myocardial ischemia and reperfusion in vivo. J Mol Cell
Cardiol 31: 1709 –1715, 2002.
Holmuhamedov EL, Jovanovic S, Dzeja PP, Jovanovic A, and
Terzic A. Mitochondrial ATP-sensitive K⫹ channels modulate cardiac mitochondrial function. Am J Physiol Heart Circ Physiol 275:
H1567–H1576, 1998.
Holmuhamedov EL, Wang L, and Terzic A. ATP-sensitive K⫹
channel openers prevent Ca2⫹ overload in rat cardiac mitochondria. J Physiol 519: 347–360, 1999.
Hoshida S, Kuzuya T, Fuji H, Yamashita N, Oe H, Hori M,
Suzuki K, Taniguchi N, and Tada M. Sublethal ischemia alters
myocardial antioxidant activity in canine heart. Am J Physiol
Heart Circ Physiol 264: H33–H39, 1993.
Huot J, Houle F, Spitz DR, and Landry J. Hsp27 phosphorylation-mediated resistance against actin fragmentation and cell death
induced by oxidative stress. Cancer Res 56: 273–279, 1996.
Ikonomidis JS, Shirai T, Weisel RD, Derylo B, Rao V, Whiteside CI, Mickle DAG, and Li R-K. Preconditioning cultured human pediatric myocytes requires adenosine and protein kinase C.
Am J Physiol Heart Circ Physiol 272: H1220 –H1230, 1997.
Ikonomidis JS, Tuniati LC, Weisel RD, Mickle DA, and Li RK.
Preconditioning human ventricular cardiomyocytes with brief periods of simulated ischaemia. Cardiovasc Res 28: 1285–1291, 1994.
Iliodromitis EK, Miki T, Liu GS, Downey JM, Cohen MV, and
Kremastinos DT. The PKC activator PMA preconditions rabbit
heart in the presence of adenosine receptor blockade: is 5⬘-nucleotidase important? J Mol Cell Cardiol 30: 2201–2211, 1998.
Illes RW and Sowyer KD. Prospective randomized clinical study
of ischemic preconditioning as an adjunct to intermittant cold
blood cardioplegia. Ann Thor Surg 65: 748 –753, 1998.
Imagawa J, Baxter GF, and Yellon DM. Genistein, a tyrosine
kinase inhibitor, blocks the “second window of protection” 48 h
after ischemic preconditioning in the rabbit. J Mol Cell Cardiol 29:
1885–1893, 1997.
Ishida T, Yarimizu K, Gute DC, and Korthuis RJ. Mechanisms
of ischemic preconditioning. Shock 8: 86 –94, 1997.
Ishihara M, Sato H, Tateishi H, Kawagoe T, Shimatani Y,
Kurisu S, Sakai K, and Ueda K. Implications of prodromal angina
pectoris in anterior wall acute myocardial infarction: acute angiographic findings and long term prognosis. J Am Coll Cardiol 30:
970 –975, 1997.
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
119.
DEREK M. YELLON AND JAMES M. DOWNEY
MYOCARDIAL PRECONDITIONING
Physiol Rev • VOL
173. Kitakaze M, Hori M, Morioka T, Minamino T, Takashima S,
Sato H, Shinozaki Y, Chujo M, Mori H, Inoue M, and Kamada
T. Infarct size-limiting effect of ischemic preconditioning is blunted
by inhibition of 5⬘-nucleotidase activity and attenuation of adenosine release. Circulation 89: 1237–1246, 1994.
174. Klein HH, Puschmann S, Schaper J, and Schaper W. The mechanism of the tetrazolium reaction in identifying experimental myocardial infarction. Virchows Arch 393: 287–297, 1981.
175. Kloner RA, Bolli R, Marban E, Reinlib L, and Braunwald E.
Medical and cellular implications of stunning, hibernation and
preconditioning: an NHLBI workshop. Circulation 97: 1848 –1867,
1998.
176. Kloner RA, Przyklenk K, Shook T, and Cannon CP. Protection
conferred by preinfarct angina is manifest in the aged heart: evidence from the Timi 4 Trial. J Thromb Thrombolysis 6: 89 –92,
1998.
177. Kloner RA, Przyklenk K, and Whittaker P. Deleterious effects
of oxygen radicals in ischemia/reperfusion: resolved and unresolved issues. Circulation 80: 1115–1127, 1989.
178. Kloner RA, Shook T, Antman EM, Cannon CP, Przyklenk K,
Yoo K, Mccabe CH, Braunwald E, and The Timi-9b Investigators. Prospective temporal analysis of the onset of preinfarction
angina versus outcome: an ancillary study in TIMI-9B. Circulation
97: 1042–1045, 1998.
179. Kloner RA, Shook T, Przyklenk K, Davis VG, Junio L, Matthews RV, Burstein S, Gibson CM, Poole WK, Cannon CP,
McCabe CH, and Braunwald E. Previous angina alters in-hospital
outcome in TIMI 4: a clinical correlate to preconditioning? Circulation 91: 37– 45, 1995.
180. Knowlton AA, Brecher P, and Apstein CS. Rapid expression of
heat shock protein in the rabbit after brief cardiac ischemia. J Clin
Invest 87: 139 –147, 1991.
181. Kodani E, Shinmura K, Xuan YT, Takano H, Auchampach JA,
Tang XL, and Bolli R. Cyclooxygenase-2 does not mediate late
preconditioning induced by activation of adenosine A1 or A3 receptors. Am J Physiol Heart Circ Physiol 281: H959 –H668, 2002.
182. Kolocassides KG, Seymour A-ML, Galiñanes M, and Hearse
DJ. Paradoxical effect of ischemic preconditioning on ischemic
contracture? NMR studies of energy metabolism and intracellular
pH in the rat heart. J Mol Cell Cardiol 28: 1045–1057, 1996.
183. Koning MMG, Gho BCG, Vanklaarwater E, Opstal RLJ,
Duncker DJ, and Verdouw PD. Rapid ventricular pacing produces myocardial protection by nonischemic activation of KATP⫹
channels. Circulation 93: 178 –186, 1996.
184. Kostitprapa C, Ockaili RA, and Kukreja RC. Bradykinin B2
receptor is involved in the late phase of preconditioning in rabbit
heart. J Mol Cell Cardiol 33: 1355–1362, 2001.
185. Krenz M, Baines CP, Yang X-M, Heusch G, Cohen MV, and
Downey JM. Acute ethanol exposure fails to elicit preconditioning-like protection in in situ rabbit hearts because of its continued
presence during ischemia. J Am Coll Cardiol 37: 601– 607, 2001.
186. Krenz M, Oldenburg O, Wimpee H, Cohen MV, Garlid KD,
Critz S, Downey JM, and Benoit JN. Opening of ATP-sensitive
potassium channels causes generation of free radicals in vascular
smooth muscle cells. Basic Res Cardiol 97: 365–373, 2002.
187. Kusama Y, Bernier M, and Hearse DJ. Exacerbation of reperfusion arrhythmias by sudden oxidant stress. Circ Res 67: 481– 489,
1990.
188. Kuzuya T, Hoshida S, Yamashita N, Fuji H, Oe H, Hori M,
Kamada T, and Tada M. Delayed effects of sublethal ischemia on
the acquisition of tolerance to ischemia. Circ Res 72: 1293–1299,
1993.
189. Laclau MN, Boudina S, Thambo JB, Tariosse L, Gouverneur
G, Bonoron-Adèle S, Saks VA, Garlid KD, and Dos Santos P.
Cardioprotection by ischemic preconditioning preserves mitochondrial function and functional coupling between adenine nucleotide
translocase and creatine kinase. J Mol Cell Cardiol 33: 947–956,
2001.
190. Landymore RW, Bayes AJ, Murphy JT, and Fris JH. Preconditioning prevents myocardial stunning after cardiac transplantation.
Ann Thorac Surg 66: 1953–1957, 1998.
191. Lasley RD and Mentzer RM. Adenosine improves recovery of
postischemic myocardial function via an adenosine A1 receptor
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
154. Iwasaka T, Nakamura S, Karakawa M, Sugiura T, and Inada
M. Cardioprotective effect of unstable angina prior to acute anterior myocardial infarction. Chest 105: 57– 61, 1994.
155. Jaberansari MT, Baxter GF, Muller CA, Latouf SE, Roth E,
Opie LH, and Yellon DM. Angiotensin-converting enzyme inhibition enhances a subthreshold stimulus to elicit delayed preconditioning in pig myocardium. J Am Coll Cardiol 37: 1996 –2001, 2001.
156. Javadov S, Lim K, Kerr P, Suleiman M, Angelini G, and
Halestrap AP. Protection of hearts from reperfusion injury by
propofol is associated with inhibition of the mitochondrial permeability transition. Cardiovasc Res 45: 360 –369, 2000.
157. Jenkins DP, Pugsley WB, Alkhulaifi AM, Kemp M, Hooper J,
and Yellon DM. Ischaemic preconditioning reduces troponin T
release in patients undergoing coronary artery bypass surgery.
Heart 77: 314 –318, 1997.
158. Jenkins DP, Pugsley WB, and Yellon DM. Ischaemic preconditioning in a model of global ischaemia: infarct size limitation, but
no reduction of stunning. J Mol Cell Cardiol 27: 1623–1632, 1995.
159. Jennings RB and Reimer KA. Factors involved in salvaging ischemic myocardium: effect of reperfusion of arterial blood. Circulation 68 Suppl 1: I-25–I-36, 1983.
160. Jimenez-Navarro M, Gomez-Doblas JJ, Alonso-Briales J, Hernandez Garcia JM, Gomez G, Alcantara AG, Rodriguez-Bailon
I, Barrera A, Espinosacaliani JS, and De Teresa E. Does
angina the week before protect against first myocardial infarction
in elderley patients? Am J Cardiol 87: 11–15, 2001.
161. Johnson JA, Gray MO, Chen C-H, and Mochly-Rosen D. A
protein kinase C translocation inhibitor as an isozyme-selective
antagonist of cardiac function. J Biol Chem 271: 24962–24966, 1996.
162. Jordan JE, Zhao Z-Q, and Vinten-Johansen J. The role of
neutrophils in myocardial ischemia-reperfusion injury. Cardiovasc
Res 43: 860 – 878, 1999.
163. Joyeux M, Godin-Ribuot D, and Ribuot C. Resistance to myocardial infarction induced by heat stress and the effect of ATPsensitive potassium channel blockade in the rat isolated heart. Br J
Pharmacol 125: 1085–1088, 1998.
164. Kandasamy RA, Yu FH, Harris R, Boucher A, Hanrahan JW,
and Orlowski J. Plasma membrane Na⫹/H⫹ exchanger isoforms
(NHE-1, -2, and -3) are differentially responsive to second messenger agonists of the protein kinase A and C pathways. J Biol Chem
270: 29209 –29216, 1995.
164a.Karck M, Rahmanian P, and Haverick A. Ischemic preconditioning enhances donor heart preservation. Transplantation 62: 17–22,
1996.
165. Karmazyn M and Moffat MP. Role of Na⫹/H⫹ exchange in cardiac physiology and pathophysiology: mediation of myocardial
reperfusion injury by the pH paradox. Cardiovasc Res 27: 915–924,
1993.
166. Karsch M, Baufreton C, Fernandez C, Brunet S, Pasteau F,
Astier A, and Loisance DY. Preconditioning with cromokalim
improves long-term myocardial preservation for heart transplantation. Ann Thorac Surg 66: 417– 424, 1998.
167. Kaukoranta P, Lepojarvi MPK, Ylitalo KV, Kiviluoma KT, and
Peuhkurinen KJ. Normothermic retrograde blood cardioplegia
with or without preceding ischemic preconditioning. Ann Thorac
Surg 63: 1268 –1274, 1997.
168. Kerensky RA, Franco E, Schlaifer JD, Pepine CJ, and Belardinelli L. Effect of theophylline on the warm up phenomenon.
Am J Cardiol 84: 1077–1080, 1999.
169. Kevelaitis E, Peynet J, Mouas C, Launay J-M, and Menasche
P. Opening of potassium channels: the common cardioprotective
link between preconditioning and natural hibernation. Circulation
99: 3079 –3085, 1999.
170. Kim SO, Baines CP, Critz SD, Pelech SL, Katz S, Downey JM,
and Cohen MV. Ischemia induced activation of heat shock protein
27 kinases and casein kinase 2 in the preconditioned rabbit heart.
Biochem Cell Biol 77: 559 –567, 1999.
171. Kirino T. Ischemic tolerance. J Cereb Blood Flow Metab 22: 1283–
1296, 2002.
172. Kirsch GE, Codina J, Birnbaumer L, and Brown AM. Coupling
of ATP-sensitive K⫹ channels to A1 receptors by G proteins in rat
ventricular myocytes. Am J Physiol Heart Circ Physiol 259: H820 –
H826, 1990.
1145
1146
192.
193.
194.
195.
196.
198.
199.
200.
201.
202.
203.
204.
205.
206.
207.
208.
209.
210.
211.
212.
213.
mechanism. Am J Physiol Heart Circ Physiol 263: H1460 –H1465,
1992.
Lawson CS and Downey JM. Preconditioning: state of the art
myocardial protection. Cardiovasc Res 27: 542–550, 1993.
Lee HT, Lafaro RJ, and Reed GE. Pretreatment of human myocardium with adenosine during open heart surgery. J Cardiac Surg
10: 665– 676, 1995.
Lee TM, Su SF, Chou TF, Lee YT, and Tsai CH. Loss of
preconditioning by attenuated activation of myocardial ATP sensitive potassium channels in elderly patients undergoing coronary
angioplasty. Circulation 105: 334 –340, 2002.
Leesar MA, Stoddard M, Ahmed M, Broadbent J, and Bolli R.
Preconditioning of human myocardium with adenosine during coronary angioplasty. Circulation 95: 2500 –2507, 1997.
Leesar MA, Stoddard MF, Dawn B, Jasti VG, Masden R, and
Bolli R. Delayed preconditioning-mimetic action of nitroglycerin in
patients undergoing coronary angioplasty. Circulation 103: 2935–
2941, 2001.
Leesar MA, Stoddard MF, Manchikalapudi S, and Bolli R.
Bradykinin-induced preconditioning in patients undergoing coronary angioplasty. J Am Coll Cardiol 34: 639 – 650, 1999.
Li G, Chen S, Lu E, and Li Y. Ischemic preconditioning improves
preservation with cold blood cardioplegia in valve replacement
patients. Eur J Cardiothoracic Surg 15: 653– 657, 1999.
Li G, Whittaker P, Yao M, Kloner RA, and Przyklenk K. The
gap junction uncoupler heptanol abrogates infarct size reduction
with preconditioning in mouse hearts. Cardiovasc Pathol 11: 158 –
165, 2002.
Li GC, Vasquez JA, Gallagher KP, and Lucchesi BR. Myocardial
protection with preconditioning. Circulation 82: 609 – 619, 1990.
Li Y and Kloner RA. Cardioprotective effects of ischemic preconditioning are not mediated by prostanoids. Cardiovasc Res 26:
226 –231, 1992.
Liang BT and Gross GJ. Direct preconditioning of cardiac myocytes via opioid receptors and KATP channels. Circ Res 84: 1396 –
1400, 1999.
Liu GS, Cohen MV, Mochly-Rosen D, and Downey JM. Protein
kinase C-⑀ is responsible for the protection of preconditioning in
rabbit cardiomyocytes. J Mol Cell Cardiol 31: 1937–1948, 1999.
Liu GS, Richards SC, Olsson RA, Mullane K, Walsh RS, and
Downey JM. Evidence that the adenosine A3 receptor may mediate the protection afforded by preconditioning in the isolated rabbit heart. Cardiovasc Res 28: 1057–1061, 1994.
Liu GS, Stanley AWH, and Downey J. Cyclooxygenase products
are not involved in the protection against myocardial infarction
afforded by preconditioning in rabbit. Am J Cardiovasc Pathol 4:
56 – 63, 1992.
Liu GS, Thornton J, Van Winkle DM, Stanley AWH, Olsson
RA, and Downey JM. Protection against infarction afforded by
preconditioning is mediated by A1 adenosine receptors in rabbit
heart. Circulation 84: 350 –356, 1991.
Liu Y, Ren G, O’Rourke B, Marban E, and Seharaseyon J.
Pharmacological comparison of native mitochondrial KATP channels with molecularly defined surface KATP channels. Mol Pharmacol 59: 225–230, 2001.
Liu Y, Sato T, O’Rourke B, and Marban E. Mitochondrial ATPdependent potassium channels: novel effectors of cardioprotection? Circulation 97: 2463–2469, 1998.
Liu Y, Ytrehus K, and Downey JM. Evidence that translocation
of protein kinase C is a key event during ischemic preconditioning
of rabbit myocardium. J Mol Cell Cardiol 26: 661– 668, 1994.
Lu HR, Remeysen P, and De Clerck F. Does the antiarrhythmic
effect of ischemic preconditioning in rats involve the L-arginine
nitric oxide pathway? J Cardiovasc Pharmacol 25: 524 –530, 1995.
Ma X-L, Kumar S, Gao F, Louden CS, Lopez BL, Christopher
TA, Wang C, Lee JC, Feuerstein GZ, and Yue T-L. Inhibition of
p38 mitogen-activated protein kinase decreases cardiomyocyte apoptosis and improves cardiac function after myocardial ischemia
and reperfusion. Circulation 99: 1685–1691, 1999.
Marber MS, Joy MD, and Yellon DM. Editorial. Warm-up angina:
is it ischaemic preconditioning. Br Heart J 72: 213–215, 1994.
Marber MS, Latchman DS, Walker JM, and Yellon DM. Cardiac
stress protein elevation 24 hours after brief ischemia or heat stress
Physiol Rev • VOL
is associated with resistance to myocardial infarction. Circulation
88: 1264 –1272, 1993.
214. Marber MS, Mestril R, Chi SH, Sayen R, Yellon DM, and
Dillmann WH. Overexpression of rat inducible 70-kD heat stress
protein in a transgenic mouse increases resistance of the heart to
ischaemic injury. J Clin Invest 95: 1446 –1456, 2002.
215. Maroko PR, Kjekshus JK, Sobel BE, Watanabe T, Covell JW,
Ross J Jr, and Braunwald E. Factors influencing infarct size
following experimental coronary artery occlusions. Circulation 43:
67– 82, 1971.
216. Maroko PR, Libby P, Bloor CM, Sobel BE, and Braunwald E.
Reduction by hyaluronidase of myocardial necrosis following coronary artery occlusion. Circulation 46: 430 – 437, 1972.
217. Maroko PR, Libby P, Sobel BE, Bloor CM, Shell WE, Covell
JW, and Braunwald E. Effect of glucose-insulin-potassium infusion on myocardial infarction following experimental coronary
artery occlusion. Circulation 45: 1160 –1175, 1972.
218. Mason MJ, Patel DJ, Paul V, and Ilsley CD. Time course and
extent of collateral vessel recruitment during coronary angioplasty.
Coron Artery Dis 13: 17–23, 2002.
219. Matsuyama N, Leavens JE, McKinnon D, Gaudette GR, Aksehirli TO, and Krukenkamp IB. Ischemic but not pharmacological
preconditioning requires protein synthesis. Circulation 102 Suppl
3: III-312–III-318, 2000.
220. Maulik N, Watanabe M, Zu Y-L, Huang C-K, Cordis GA, Schley
JA, and Das DK. Ischemic preconditioning triggers the activation
of MAP kinases and MAPKAP kinase 2 in rat hearts. FEBS Lett 396:
233–237, 1996.
221. Maulik N, Yoshida T, Zu Y-L, Sato M, Banerjee A, and Das DK.
Ischemic preconditioning triggers tyrosine kinase signaling: a potential role for MAPKAP kinase 2. Am J Physiol Heart Circ Physiol
275: H1857–H1864, 1998.
222. Mei DA, Elliot GT, and Gross GJ. KATP channels mediate late
preconditioning against infarction produced by monophosphory
lipid A. Am J Physiol Heart Circ Physiol 271: H2723–H2729, 1996.
223. Meldrum DR, Cain BS, Cleveland JC Jr, Meng X, Ayala A,
Banerjee A, and Harken AH. Adenosine decreases post-ischaemic cardiac TNF-alpha production: anti-inflammatory implications for preconditioning and transplantation. Immunology 92:
472– 477, 1997.
224. Meng X, Brown JM, Ao L, Banerjee A, and Harken AH. Norepinephrine induces cardiac heat shock protein 70 and delayed
cardioprotection in the rat through ␣1 adrenoceptors. Cardiovasc
Res 32: 374 –383, 1996.
225. Meng X, Shames BD, Pulido EJ, Meldrum DR, Ao L, Joo KS,
Harken AH, and Banerjee A. Adrenergic induction of bimodal
myocardial protection: signal transduction and cardiac gene reprogramming. Am J Physiol Regul Integr Comp Physiol 276: R1525–
R1533, 2002.
226. Michel MC, Li Y, and Heusch G. Mitogen-activated protein kinases in the heart. Naunyn-Schmiedebergs Arch Pharmacol 363:
245–266, 2001.
227. Miki T, Miura T, Shimamoto K, Urabe K, Sakamoto J, and
Iimura O. Do angiotensin converting enzyme inhibitors limit myocardial infarct size. Clin Exp Pharm Physiol 20: 429 – 434, 1993.
227a.Minners J, Van Den Bos EJ, Yellon DM, Schwalb H, Opie LH,
and Sack MN. Dinitrophenol, cyclosporin-A, and trimetazidine
modulate preconditioning in the isolated rat heart: support for a
mitochondrial role in cardioprotection. Cardiovasc Res 47: 68 –73,
2000.
228. Mitchell MB, Meng X, Ao L, Brown JM, Harken AH, and
Banerjee A. Preconditioning of isolated rat heart is mediated by
protein kinase C. Circ Res 76: 73– 81, 1995.
229. Miyawaki H and Ashraf M. Ca2⫹ as a mediator of ischemic
preconditioning. Circ Res 80: 790 –799, 1997.
230. Miyawaki H, Zhou X, and Ashraf M. Calcium preconditioning
elicits strong protection against ischemic injury via protein kinase
C signaling pathway. Circ Res 79: 137–146, 1996.
231. Mocanu MM, Baxter GF, and Yellon DM. Caspase inhibition and
limitation of myocardial infarct size: protection against lethal
reperfusion injury. Br J Pharmacol 130: 197–200, 2000.
232. Mocanu MM, Baxter GF, Yue Y, Critz SD, and Yellon DM. The
p38 MAPK inhibitor, SB203580, abrogates ischaemic precondition-
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
197.
DEREK M. YELLON AND JAMES M. DOWNEY
MYOCARDIAL PRECONDITIONING
Physiol Rev • VOL
252.
253.
254.
255.
256.
257.
258.
259.
260.
261.
262.
263.
264.
265.
266.
267.
268.
269.
270.
M. Effect of caspase inhibitors on myocardial infarct size and
myocyte DNA fragmentation in the ischemia-reperfused rat heart.
Cardiovasc Res 45: 642– 650, 2000.
Okazaki Y, Kodama. K, Sato H, Kitakaze M, Hirayame A,
Mishima M, Hori M, and Inoue M. Attenuation of increased
regional myocardial oxygen consumption during exercise as a major cause of warm-up. J Am Coll Cardiol 21: 1597–1604, 1993.
Okishige K, Yamashita K, Yoshinaga H, Azegami K, Satoh T,
Goseki Y, Fujii S, Ohira H, and Satake S. Electrophysiologic
effects of ischemic preconditioning on QT dispersion during coronary angioplasty. J Am Coll Cardiol 28: 70 –73, 1996.
Oldenburg O, Qin Q, Sharma AR, Cohen MV, Downey JM, and
Benoit JN. Acetylcholine leads to free radical production dependent on KATP channels, Gi proteins, phosphatidylinositol 3-kinase
and tyrosine kinase. Cardiovasc Res 55: 544 –552, 2002.
Ottani F, Galvani M, Ferrini D, Sorbello F, Limonetti P,
Pantoli D, and Rusticali F. Prodromal angina limits infarct size:
a role for ischemic preconditioning. Circulation 91: 291–297, 1995.
Ovize M, Aupetit J, Rioufol G, Loufoua J, Andre-Fouet X,
Minaire Y, and Fuacon G. Preconditioning reduces infarct size
but accelerates time to ventricular fibrillation in ischemic pig heart.
Am J Physiol Heart Circ Physiol 269: H72–H79, 1995.
Ovize M, Kloner RA, and Przyklenk K. Stretch preconditions
canine myocardium. Am J Physiol Heart Circ Physiol 266: H137–
H146, 1994.
Ovize M, Przyklenk K, Hale SL, and Kloner RA. Preconditioning does not attenuate myocardial stunning. Circulation 85: 2247–
2254, 1992.
Ovunc K. Effects of glibenclamide a KATP channel blocker, on
warm-up phenomenon in type II diabetic patients with chronic
stable angina. Clin Cardiol 23: 535–539, 2000.
Pain T, Yang X-M, Critz SD, Yue Y, Nakano A, Liu GS, Heusch
G, Cohen MV, and Downey JM. Opening of mitochondrial KATP
channels triggers the preconditioned state by generating free radicals. Circ Res 87: 460 – 466, 2000.
Pang CY, Neligan P, Zhong A, He W, Xu H, and Forrest CR.
Effector mechanism of adenosine in acute ischemic preconditioning of skeletal muscle against infarction. Am J Physiol Regul Integr
Comp Physiol 273: R887–R895, 1997.
Pang CY, Yang RZ, Zhong A, Xu N, Boyd B, and Forrest CR.
Acute ischaemic preconditioning protects against skeletal muscle
infarction in the pig. Cardiovasc Res 29: 782–788, 1995.
Parratt JR, Vegh A, Kaszala K, and Papp JG. Protection by
preconditioning and cardiac pacing against ventricular arrhythmias
resulting from ischemia and reperfusion. Ann NY Acad Sci 793:
98 –107, 1996.
Patel DJ, Purcell H, and Fox KM. Cardioprotection by opening
of the KATP channel in unstable angina: is this a clinical manifestation of myocardial preconditioning? Results of a randomised
study with nicorandil CESAR 2 investigation Clinical European
studies in angina and revsacularization. Eur Heart J 20: 51–57,
1999.
Patel HH, Hsu A, Moore J, and Gross GJ. Bw373u86, a delta
opioid agonist, partially mediates delayed cardioprotection via a
free radical mechanism that is independent of opioid receptor
stimulation. J Mol Cell Cardiol 33: 1455–1465, 2001.
Patel HH, Moore J, Hsu AK, and Gross GJ. Cardioprotection at
a distance: mesenteric artery occlusion protects the myocardium
via an opioid sensitive mechanism. J Mol Cell Cardiol 34: 1317–
1323, 2002.
Pell TJ, Yellon DM, Goodwin RW, and Baxter GF. Myocardial
ischemic tolerance following heat stress is abolished by ATP sensitive potassium channel blockade. Cardiovasc Drugs Ther 11:
679 – 686, 2002.
Perrault LP and Menasche P. Preconditioning: can natures shield
be raised against surgical ischemic-reperfusion injury? Ann Thoracic Surg 68: 1988 –1994, 1999.
Perrault LP, Menasché P, Bel A, De Chaumaray T, Peynet J,
Mondry A, Olivero P, Emanoil-Ravier R, and Moalic J-M.
Ischemic preconditioning in cardiac surgery: a word of caution.
J Thoracic Cardiovasc Surg 112: 1378 –1386, 1996.
Ping P and Murphy E. Role of p38 mitogen-activated protein
kinases in preconditioning. Circ Res 86: 921, 2000.
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
ing in rat heart but timing of administration is critical. Basic Res
Cardiol 95: 472– 478, 2000.
233. Mocanu MM, Bell RM, and Yellon DM. PI3 kinase and not
p42/p44 appears to be implicated in the protection conferred by
ischemic preconditioning. J Mol Cell Cardiol 34: 661– 668, 2002.
234. Mocanu MM, Maddock HL, Baxter GF, Lawrence CL, Standen
NB, and Yellon DM. Glimepiride, a novel sulphonyurea, does not
abolish myocardial protection afforded by either ischemic preconditioning or diazoxide. Circulation 103: 3111–3116, 2002.
235. Mockridge JW, Punn A, Latchman DS, Marber MS, and Heads
RJ. PKC-dependent delayed metabolic preconditioning is independent of transient MAPK activation. Am J Physiol Heart Circ
Physiol 279: H492–H501, 2000.
236. Morris SD and Yellon DM. Angiotensin-converting enzyme inhibitors potentiate preconditioning through bradykinin B2 receptor
activation in human heart. J Am Coll Cardiol 29: 1599 –1606, 1997.
237. Murphy E, Glasgow W, Fralix T, and Steenbergen C. Role of
lipoxygenase metabolites in ischemic preconditioning. Circ Res 76:
457– 467, 1995.
238. Murray CJ and Lopez AD. Alternate projections of mortality and
disability by cause 1990 –2020: global burden of disease study.
Lancet 349: 1498 –1504, 1997.
239. Murry CE, Jennings RB, and Reimer KA. Preconditioning with
ischemia: a delay of lethal cell injury in ischemic myocardium.
Circulation 74: 1124 –1136, 1986.
240. Murry CE, Richard VJ, Jennings RB, and Reimer KA. Myocardial protection is lost before contractile function recovers from
ischemic preconditioning. Am J Physiol Heart Circ Physiol 260:
H796 –H804, 1991.
241. Murry CE, Richard VJ, Reimer KA, and Jennings RB. Ischemic
preconditioning slows energy metabolism and delays ultrastructural damage during a sustained ischemic episode. Circ Res 66:
913–931, 1990.
242. Nagarkatti DS and Sha’afi RI. Role of p38 MAP kinase in myocardial stress. J Mol Cell Cardiol 30: 1651–1664, 1998.
243. Nakamura M, Wang NP, Zhao ZQ, Wilcox JN, Thourani VH,
Guyton RA, and Vinten-Johansen J. Preconditioning decreases
Bax expression, PMN accumulation and apoptosis in reperfused rat
heart. Cardiovasc Res 45: 661– 670, 2002.
244. Nakano A, Baines CP, Kim SO, Pelech SL, Downey JM, Cohen
MV, and Critz SD. Ischemic preconditioning activates MAPKAPK2 in the isolated rabbit heart: evidence for involvement of p38
MAPK. Circ Res 86: 144 –151, 2000.
245. Nakano A, Cohen MV, Critz S, and Downey JM. Sb 203580, an
inhibitor of p38 MAPK, abolishes infarct-limiting effect of ischemic
preconditioning in isolated rabbit hearts. Basic Res Cardiol 95:
466 – 471, 2000.
246. Nakano A, Heusch G, Cohen MV, and Downey JM. Preconditioning one myocardial region does not necessarily precondition
the whole rabbit heart. Basic Res Cardiol 97: 35–39, 2001.
247. Nakano A, Liu GS, Heusch G, Downey JM, and Cohen MV.
Exogenous nitric oxide can trigger a preconditioned state through
a free radical mechanism, but endogenous nitric oxide is not a
trigger of classical ischemic preconditioning. J Mol Cell Cardiol 32:
1159 –1167, 2000.
248. Napoli C, Liguori A, Chiariello M, Di Leso N, Condorelli M,
and Ambrosio G. New-onset angina preceding acute myocardial
infarction is associated with improved contractile recovery after
thrombolysis. Eur Heart J 19: 411– 419, 1998.
249. Noma A. ATP-regulated potassium channels in cardiac muscle.
Nature 305: 147–148, 1983.
250. Ockaili R, Emani VR, Okubo S, Brown M, Krottapalli K, and
Kukreja RC. Opening of mitochondrial KATP channel induces early
and delayed cardioprotective effect: role of nitric oxide. Am J
Physiol Heart Circ Physiol 277: H2425–H2434, 1999.
250a.Ohno M, Takemura G, Ohno A, Misao J, Hayakawa Y, Minatoguchi S, Fujiwara T, and Fujiwara H. Apoptotic myocytes
in infarct area in rabbit hearts may be oncotic myocytes with DNA
fragmentation: analysis by immunogold electron microscopy combined with in situ nick end-labeling. Circulation 98: 1422–1430,
1998.
251. Okamura T, Miura T, Takemura G, Fujiwara H, Iwamoto H,
Kawamura S, Kimura M, Ikeda Y, Iwatate M, and Matsuzaki
1147
1148
DEREK M. YELLON AND JAMES M. DOWNEY
Physiol Rev • VOL
289.
290.
291.
292.
293.
294.
295.
296.
297.
298.
299.
300.
301.
302.
303.
304.
305.
306.
307.
T, Moriuchi M, Hibiya K, Tamura Y, and Ozawa Y. Anti-ischemic effects of nicorandil during coronary angioplasty in humans.
Cardiovasc Drugs Ther 9: 257–263, 1995.
Sakai K, Yamagata T, Teragawa H, Matsuura H, and Chayama
K. Nicorandil enhances myocardial tolerance to ischemia without
progressive collateral recruitment during coronary angioplasty.
Circ J 66: 317–322, 2002.
Saltman AE, Aksehirli TO, Valiunas V, Gaudette GR, Matsuyama N, Brink P, and Krukenkamp IB. Gap junction uncoupling
protects the heart against ischemia. J Thoracic Cardiovasc Surg
124: 371–376, 2002.
Sanada S, Kitakaze M, Papst PJ, Hatanaka K, Asanuma H, Aki
T, Shinozaki Y, Ogita H, Node K, Takashima S, Asakura M,
Yamada J, Fukushima T, Ogai A, Kuzuya T, Mori H, Terada N,
Yoshida K, and Hori M. Role of phasic dynamism of p38 mitogenactivated protein kinase activation in ischemic preconditioning of
the canine heart. Circ Res 88: 175–180, 2001.
Sanz E, Garcia-Dorado D, Oliveras J, Barrabes JA, Gonzalez
MA, Ruiz-Meana M, Solares J, Carreras MJ, Garcia-Lafuente
A, and Desco M. Dissociation between anti-infarct effect and
anti-edema effect of ischemic preconditioning. Am J Physiol Heart
Circ Physiol 268: H233–H241, 2002.
Sato H, Miki T, Vallabhapurapu RP, Wang P, Liu G-S, Cohen
MV, and Downey JM. The mechanism of protection from 5(Nethyl-N-isopropyl) amiloride differs from that of ischemic preconditioning in rabbit heart. Basic Res Cardiol 92: 339 –350, 1997.
Sato M, Cordis GA, Maulik N, and Das DK. Sapks regulation of
ischemic preconditioning. Am J Physiol Heart Circ Physiol 279:
H901–H907, 2000.
Sato T, O’Rourke B, and Marbán E. Modulation of mitochondrial
ATP-dependent K⫹ channels by protein kinase C. Circ Res 83:
110 –114, 1998.
Sato T, Sasaki N, O’Rourke B, and Marban E. Nicorandil, a
potent cardioprotective agent, acts by opening mitochondrial ATPdependent potassium channels. J Am Coll Cardiol 35: 514 –518,
2000.
Sato T, Sasaki N, Seharaseyon J, O’Rourke B, and Marbán E.
Selective pharmacological agents implicate mitochondrial but not
sarcolemmal KATP channels in ischemic cardioprotection. Circulation 101: 2418 –2423, 2000.
Saurin AT, Martin JL, Heads RJ, Foley C, Mockridge JW,
Wright MJ, Wang Y, and Marber MS. The role of differential
activation of p38-mitogen-activated protein kinase in preconditioned ventricular myocytes. FASEB J 14: 2237–2246, 2000.
Schaefer S, Carr LJ, Prussel E, and Ramasamy R. Effects of
glycogen depletion on ischemic injury in isolated rat hearts: insights into preconditioning. Am J Physiol Heart Circ Physiol 268:
H935–H944, 2002.
Schneider S, Chen W, Hou J, Steenbergen C, and Murphy E.
Inhibition of p38 MAPK alpha/beta reduces ischemic injury and
does not block protective effects of preconditioning. Am J Physiol
Heart Circ Physiol 280: H499 –H508, 2002.
Schott RJ, Rohmann S, Braun ER, and Schaper W. Ischemic
preconditioning reduces infarct size in swine myocardium. Circ
Res 66: 1133–1142, 1990.
Schulman D, Latchman DS, and Yellon DM. Effect of aging on
the ability of preconditioning to protect rat hearts from ischemiareperfusion injury. Am J Physiol 281: H1630 –H1636, 2001.
Schulz R, Post H, Sakka S, Wallbridge DR, and Heusch G.
Intraischemic preconditioning: increased tolerance to sustained
low-flow ischemia by a brief episode of no-flow ischemia without
intermittent reperfusion. Circ Res 76: 942–950, 1995.
Schulz R, Post H, Vahlhaus C, and Heusch G. Ischemic preconditioning in pigs: a graded phenomenon. Its relation to adenosine
and bradykinin. Circulation 98: 1022–1029, 1998.
Schulz R, Rose J, and Heusch G. Involvement of activation of
ATP-dependent potassium channels in ischemic preconditioning in
swine. Am J Physiol Heart Circ Physiol 267: H1341–H1352, 1994.
Schwanke U, Konietzka I, Duschin A, Li X, Schulz R, and
Heusch G. No ischemic preconditioning in heterozygous connexin43-deficient mice. Am J Physiol Heart Circ Physiol 283:
H1740 –H1742, 2002.
Sekili S, Jeroudi MO, Tang X-L, Zughaib M, Sun J-Z, and
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
271. Ping P, Takano H, Zhang J, Tang X-L, Qiu Y, Li RCX, Banerjee
S, Dawn B, Balafonova Z, and Bolli R. Isoform-selective activation of protein kinase C by nitric oxide in the heart of conscious
rabbits: a signaling mechanism for both nitric oxide-induced and
ischemia-induced preconditioning. Circ Res 84: 587– 604, 1999.
272. Ping P, Zhang J, Cao X, Li RCX, Kong D, Tang X-L, Qiu Y,
Manchikalapudi S, Auchampach JA, Black RG, and Bolli R.
PKC-dependent activation of p44/p42 MAPKs during myocardial
ischemia-reperfusion in conscious rabbits. Am J Physiol Heart
Circ Physiol 276: H1468 –H1481, 1999.
273. Ping P, Zhang J, Huang S, Cao X, Tang X-L, Li RCX, Zheng Y-T,
Qiu Y, Clerk A, Sugden P, Han J, and Bolli R. PKC-dependent
activation of p46/p54 JNKs during ischemic preconditioning in
conscious rabbits. Am J Physiol Heart Circ Physiol 277: H1771–
H1785, 1999.
274. Ping P, Zhang J, Qiu Y, Tang X-L, Manchikalapudi S, Cao X,
and Bolli R. Ischemic preconditioning induces selective translocation of protein kinase C isoforms ⑀ and ␩ in the heart of conscious rabbits without subcellular redistribution of total protein
kinase C activity. Circ Res 81: 404 – 414, 1997.
275. Ping P, Zhang J, Zheng Y-T, Li RCX, Dawn B, Tang X-L,
Takano H, Balafonova Z, and Bolli R. Demonstration of selective protein kinase C-dependent activation of Src and Lck tyrosine
kinases during ischemic preconditioning in conscious rabbits. Circ
Res 85: 542–550, 1999.
276. Piot C, Martini J-F, Bui S, and Wolfe CL. Ischemic preconditioning attenuates ischemia/reperfusion-induced activation of
caspases and subsequent cleavage of poly (ADP-ribose) polymerase in rat hearts in vivo. Cardiovasc Res 44: 536 –542, 1999.
277. Post H, Schulz R, Behrends M, Gres P, Umschlag C, and
Heusch G. No involvement of endogenous nitric oxide in classical
ischemic preconditioning in swine. J Mol Cell Cardiol 32: 725–733,
2000.
278. Przyklenk K, Bauer B, Ovize M, Kloner RA, and Whittaker P.
Regional ischemic “preconditioning” protects remote virgin myocardium from subsequent sustained coronary occlusion. Circulation 87: 893– 899, 1993.
279. Przyklenk K, Hata K, and Kloner RA. Is calcium a mediator of
infarct size reduction with preconditioning in canine myocardium?
Circulation 96: 1305–1312, 1997.
280. Przyklenk K and Whittaker P. Brief antecedent ischemia enhances recombinant tissue plasminogen activator-induced coronary thrombolysis by adenosine-mediated mechanism. Circulation
102: 88 –95, 2000.
281. Qian YZ, Bernado NL, Nayeem MA, Chelliah J, and Kukreja
RA. Introduction of 72-kDa heat shock protein does not produce
second window of ischaemic precondionting in rat heart. Am J
Physiol Heart Circ Physiol 276: H224 –H234, 2002.
282. Qin Q, Downey JM, and Cohen MV. Acetylcholine but not adenosine triggers preconditioning through PI3-kinase and a tyrosine
kinase. Am J Physiol Heart Circ Physiol 284: H727–H734, 2003.
283. Qiu Y, Ping P, Tang X-L, Manchikalapudi S, Rizvi A, Zhang J,
Takano H, Wu W-J, Teschner S, and Bolli R. Direct evidence
that protein kinase C plays an essential role in the development of
late preconditioning against myocardial stunning in conscious rabbits and that ⑀ is the isoform involved. J Clin Invest 101: 2182–2198,
1998.
284. Reimer KA and Jennings RB. The “wavefront phenomenon” of
myocardial ischemic cell death. II. Transmural progression of necrosis within the framework of ischemic bed size (myocardium at
risk) and collateral flow. Lab Invest 40: 633– 644, 1979.
285. Reimer KA, Murry CE, and Richard VJ. The role of neutrophils
and free radicals in the ischemic-reperfused heart: why the confusion and controversy? J Mol Cell Cardiol 21: 1225–1239, 1989.
286. Rinaldi CA, Masani MD, Linka AZ, and Hall RJ. Effect of
repetitive episodes of exercise induced myocardial ischaemia on
left ventricular function in patients with chronic stable angina:
evidence for cumulative stunning or ischaemic preconditioning.
Heart 81: 404 – 411, 1999.
287. Sack S, Mohri M, Arras M, Schwarz ER, and Schaper W.
Ischemic preconditioning: time course of renewal in the pig. Cardiovasc Res 27: 551–555, 1993.
288. Saito S, Mizumura T, Takayama T, Honye J, Fukui T, Kamata
MYOCARDIAL PRECONDITIONING
308.
309.
310.
311.
312.
314.
315.
316.
317.
318.
319.
320.
321.
322.
323.
324.
325.
326.
327.
Physiol Rev • VOL
328.
329.
330.
331.
332.
333.
334.
335.
336.
337.
338.
339.
340.
341.
342.
343.
344.
345.
346.
Bhattacharya S, and Auchampach JA. A1 or A3 adenosine receptors induce late preconditioning against infarction in conscious
rabbits by different mechanisms. Circ Res 88: 520 –528, 2001.
Takano H, Manchikalapudi S, Tang X-L, Qiu Y, Rizvi A, Jadoon AK, Zhang Q, and Bolli R. Nitric oxide synthase is the
mediator of late preconditioning against myocardial infarction in
conscious rabbits. Circulation 98: 441– 449, 1998.
Takano H, Tang X-L, Qiu Y, Guo Y, French BA, and Bolli R.
Nitric oxide donors induce late preconditioning against myocardial
stunning and infarction in conscious rabbits via an antioxidantsensitive mechanism. Circ Res 83: 73– 84, 1998.
Takano H, Tang X-L, and Bolli R. Differential roles of KATP
channels in late preconditioning against myocardial stunning and
infarction in rabbits. Am J Physiol Heart Circ Physiol 279: H2350 –
H2359, 2000.
Takashi E, Wang Y, and Ashraf M. Activation of mitochondrial
KATP channel elicits late preconditioning against myocardial infarction via protein kinase C signaling pathway. Circ Res 85: 1146 –
1153, 1999.
Tamura K, Tsuji H, Nishiue T, Tokunaga S, and Iwasaka T.
Association of preceding angina with in-hospital life threating ventricular tacharrhythmias and late potentials in patients with a first
acute myocardial infarction. Am Heart J 133: 297–301, 1997.
Tanaka M, Fujiwara H, Yamasaki K, Miyamae M, Yokota R,
Hasegawa K, Fujiwara T, and Sasayama S. Ischemic preconditioning elevates cardiac stress protein but does not limit infarct size
24 or 48 h later in rabbits. Am J Physiol Heart Circ Physiol 267:
H1476 –H1482, 1994.
Tang X, Qiu Y, Park S, Sun J, Kalya A, and Bolli R. Time course
of late preconditioning against myocardial stunning in conscious
pigs. Circ Res 79: 423– 434, 1996.
Tang X-L, Qiu Y, Turrens JF, Sun JZ, and Bolli R. Late preconditioning against stunning is not mediated by increased antioxidant
defenses in conscious pigs. Am J Physiol Heart Circ Physiol 273:
H1652–H1657, 2002.
Tanno M, Tsuchida A, Nozawa Y, Matsumoto T, Hasegawa T,
Miura T, and Shimamoto K. Roles of tyrosine kinase and protein
kinase C in infarct size limitation by repetitive ischemic preconditioning in the rat. J Cardiovasc Pharmacol 35: 345–352, 2000.
Teoh LKK, Grant R, Hulf JA, Pugsley WB, and Yellon DM. A
comparison between ischemic preconditioning, intermittant crossclamp fibrillation and cold crystalloid cardioplegia for myocardial
protection during coronary artery bypass graft surgery. Cardiovasc
Surgery 10: 251–255, 2002.
Teoh LKK, Grant R, Hulf JA, Pugslry WB, and Yellon DM. The
effect of preconditioning (ischaemic and pharmacological) on myocardial necrosis following coronary artery bypass surgery. Cardiovasc Res 53: 175–180, 2002.
The Iona Study Group. Effect of nicorandil on coronary events in
patients with stable angina: the impact of nicorandil in angina
(IONA) randomised trial. Lancet 359: 1269 –1275, 2002.
Thornton J, Striplin S, Liu GS, Swafford A, Stanley AWH, Van
Winkle DM, and Downey JM. Inhibition of protein synthesis does
not block myocardial protection afforded by preconditioning. Am J
Physiol Heart Circ Physiol 259: H1822–H1825, 1990.
Tiefenbrunn AJ and Sobel BE. Timing of coronary recanalization. Circulation 85: 2311–2315, 1992.
Toller WG, Gross ER, Kersten JR, Pagel PS, Gross GJ, and
Warltier DC. Sarcolemmal and mitochondrial adenosine triphosphate-dependent potassium channels: mechanism of desfluraneinduced cardioprotection. Anesthesiology 92: 1731–1739, 2000.
Tomai F. Warm up phenomenon and preconditioning in clinical
practice. Heart 87: 99 –100, 2002.
Tomai F, Crea F, Chiariello L, and Gioffrè PA. Ischemic preconditioning in humans: models, mediators, and clinical relevance.
Circulation 100: 559 –563, 1999.
Tomai F, Crea F, Danesi A, Perino M, Gaspardone A, Ghini
AS, Cascarona MT, Chiariello L, and Gioffre PA. Mechanisms
of the warm-up phenomenon. Eur Heart J 17: 1022–1027, 1996.
Tomai F, Crea F, Gaspardone A, Versaci F, De Paulis R, Penta
De Peppo A, Chiariello L, and Gioffrè PA. Ischemic preconditioning during coronary angioplasty is prevented by glibenclamide,
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
313.
Bolli R. Effect of adenosine on myocardial stunning in the dog.
Circ Res 76: 82–94, 1995.
Shattock MJ, Lawson CS, Hearse DJ, and Downey JM. Electrophysiological characteristics of repetitive ischemic preconditioning in the pig heart. J Mol Cell Cardiol 28: 1339 –1347, 1996.
Shen YT, Fallon JT, Iwase M, and Vatner SF. Innate protection
of baboon myocardium: effects of coronary artery occlusion and
reperfusion. Am J Physiol Heart Circ Physiol 270: H1812–H1818,
1996.
Shiki K and Hearse DJ. Preconditioning of ischemic myocardium: reperfusion-induced arrhythmias. Am J Physiol Heart Circ
Physiol 253: H1470 –H1476, 1987.
Shimizu N, Yoshiyama M, Omura T, Hanatani A, Kim S,
Takeuchi K, Iwao H, and Yoshikawa J. Activation of mitogenactivated protein kinases and activator protein-1 in myocardial
infarction in rats. Cardiovasc Res 38: 116 –124, 1998.
Shinmura A, Tang X-L, Xuan Y-T, Wang Y, Xuan YT, Liu SQ,
Takano H, Bhatnagar A, and Bolli R. Cyclooxygenase-2 mediates the cardioprotective effect of the late phase of ischemic preconditioning in conscious rabbits. Proc Natl Acad Sci USA 97:
10197–10202, 2000.
Shinmura K, Xuan YT, Tang XL, Kodani E, Han H, Zhu Y, and
Bolli R. Inducible nitric oxide synthase modulates cyclooxygenase-2 activity in the heart of conscious rabbits during the late phase
of ischemic preconditioning. Circ Res 90: 602– 608, 2002.
Shirai T, Rao V, Weisel RD, Ikonomidis JS, Li R-K, Tumiati
LC, Merante F, and Mickle DA. Preconditioning human cardiomyocytes and endothelial cells. J Thoracic Cardiovasc Surg 115:
210 –219, 1998.
Silva PH, Dillon D, and Van Wylen DGL. Adenosine deaminase
inhibition augments interstitial adenosine but does not attenuate
myocardial infarction. Cardiovasc Res 29: 616 – 623, 1995.
Smith RM, Suleman N, McCarthy J, and Sack MN. Classic
ischemic but not pharmacologic preconditioning is abrogated following genetic ablation of the TNFalpha gene. Cardiovasc Res 55:
553–560, 2002.
Speechly-Dick ME, Grover GJ, and Yellon DM. Does ischemic
preconditioning in the human involve protein kinase C and the
ATP-dependent K⫹ channel? Studies of contractile function after
simulated ischemia in an atrial in vitro model. Circ Res 77: 1030 –
1035, 1995.
Steenbergen C, Perlman ME, London RE, and Murphy E.
Mechanism of preconditioning: ionic alterations. Circ Res 72: 112–
125, 1993.
Steeves G, Singh N, and Singal PK. Preconditioning and antioxidant defense against reperfusion injury. Ann NY Acad Sci 723:
116 –127, 1994.
Stewart RA, Simmonds MB, and Williams MJ. Time course of
warm-up in stable angina. Am J Cardiol 76: 70 –73, 1995.
Strohm C, Barancik T, Bruhl ML, Kilian SA, and Schaper W.
Inhibition of the ER-kinase cascade by PD98059 and UO126 counteracts ischemic preconditioning in pig myocardium. J Cardiovasc
Pharmacol 36: 218 –229, 2002.
Sumeray MS and Yellon DM. Ischaemic preconditioning reduces
infarct size following global ischaemia in the murine myocardium.
Basic Res Cardiol 93: 384 –390, 1998.
Sun J-Z, Tang X-L, Knowlton AA, Park S-W, Qiu Y, and Bolli
R. Late preconditioning against myocardial stunning: an endogenous protective mechanism that confers resistance to postischemic
dysfunction 24 h after brief ischemia in conscious pigs. J Clin
Invest 95: 388 – 403, 1995.
Sun J-Z, Tang X-L, Park S-W, Qiu Y, Turrens JF, and Bolli R.
Evidence for an essential role of reactive oxygen species in the
genesis of late preconditioning against myocardial stunning in conscious pigs. J Clin Invest 97: 562–576, 1996.
Suzuki M, Sasaki N, Miki T, Sakamoto N, Ohmoto-Sekine Y,
Tamagawa M, Seino S, Marban E, and Nakaya H. Role of
sarcolemmal K(ATP) channels in cardioprotection against ischemia/reperfusion injury in mice. J Clin Invest 109: 509 –516, 2002.
Szekeres L, Balint Z, Karescu S, Tosaki A, and Udvary E. On
the 7-oxo-PG12 induced late appearing long lasting cytoprotective
effect. Prog Clin Biol Res 301: 143–147, 1989.
Takano H, Bolli R, Black RG Jr, Kodani E, Tang X-L, Yang Z,
1149
1150
347.
348.
349.
350.
352.
353.
354.
355.
356.
357.
358.
359.
360.
361.
362.
363.
364.
365.
366.
a selective ATP-sensitive K⫹ channel blocker. Circulation 90: 700 –
705, 1994.
Tomai F, Crea F, Gaspardone A, Versaci F, De Paulis R,
Polisca P, Chiariello L, and Gioffrè PA. Effects of A1 adenosine
receptor blockade by bamiphylline on ischaemic preconditioning
during coronary angioplasty. Eur Heart J 17: 846 – 853, 1996.
Tomai F, Crea F, Gaspardone A, Versaci F, Ghini AS, De
Paulis R, Chiariello L, and Gioffre PA. Phentolamine prevents
adaptation to ischaemia during coronary angioplasty: role of alpha
adrenergic receptors in ischemic preconditioning. Circulation 96:
2171–2177, 1997.
Tomai F, Crea F, Gaspardone A, Versaci F, Ghini C, Desideri
G, Chiariello L, and Gioffre PA. Effects of naloxone on myocardial ischemic preconditioning in humans. J Am Coll Cardiol 33:
1863–1869, 1999.
Tomai F, Danesi A, Ghini AS, Crea F, Perino M, Gaspardone
A, Ruggeri G, Chiarello L, and Gioffre PA. Effects of KATP
channel blockade. Eur Heart J 20: 196 –202, 1999.
Tomai F, Depaulis R, Pento De Pepo A, Colagrande L, Caprara E, Polisca P, Dematteis G, Ghini AS, Forlani S, Collela
D, and Chiariello L. Beneficial impact of isoflurane during coronary artery bypass surgery on troponin I release. Int J Cardiol 9:
1007–1014, 1999.
Tong H, Chen W, Steenbergen C, and Murphy E. Ischemic
preconditioning activates phosphatidylinositol-3-kinase upstream
of protein kinase C. Circ Res 87: 309 –315, 2000.
Topol EJ. Acute myocardial infarction: thrombolysis. Heart 83:
122–126, 2000.
Tritto I, D’Andrea D, Eramo N, Scognamiglio A, De Simone C,
Violante A, Esposito A, Chiariello M, and Ambrosio G. Oxygen
radicals can induce preconditioning in rabbit hearts. Circ Res 80:
743–748, 1997.
Tsuchida A, Thompson R, Olsson RA, and Downey JM. The
anti-infarct effect of an adenosine A1-selective agonist is diminished after prolonged infusion as is the cardioprotective effect of
ischaemic preconditioning in rabbit heart. J Mol Cell Cardiol 26:
303–311, 1994.
Turrens JF, Thornton J, Barnard ML, Snyder S, Liu G, and
Downey JM. Protection from reperfusion injury by preconditioning hearts does not involve increased antioxidant defenses. Am J
Physiol Heart Circ Physiol 262: H585–H589, 1992.
Tzivoni D and Maybaum S. Attenuation of severity of myocardial
ischemia during repeated daily ischemic episodes. J Am Coll Cardiol 30: 119 –124, 1997.
Vahlhaus C, Schulz R, Post H, Rose J, and Heusch G. Prevention of ischemic preconditioning only by combined inhibition of
protein kinase C and protein tyrosine kinase in pigs. J Mol Cell
Cardiol 30: 197–209, 1998.
Vanden Hoek TL, Becker Z-H, Shao C-Q, Li LB, and Schumacker PT. Preconditioning in cardiomyocytes protects by attenuating oxidant stress at reperfusion. Circ Res 86: 541–548, 2000.
Vanderheide R and Ganote C. Increased myocyte fragility following anoxic injury. J Mol Cell Cardiol 19: 1085–1103, 1987.
Vane JR, Bakhle YS, and Blotting RM. Cyclooxygnase 1 and 2.
Annu Rev Pharmacol Toxicol 38: 97–120, 1998.
Van Winkle DM, Chien GL, Wolff RA, Soifer BE, Kuzume K,
and Davis RF. Cardioprotection provided by adenosine receptor
activation is abolished by blockade of the KATP channel. Am J
Physiol Heart Circ Physiol 266: H829 –H839, 1994.
Van Winkle DM, Thornton JD, Downey DM, and Downey JM.
The natural history of preconditioning: cardioprotection depends
on duration of transient ischemia and time to subsequent ischemia.
Coronary Artery Dis 2: 613– 619, 1991.
Van Wylen DGL. Effect of ischemic preconditioning on interstitial
purine metabolite and lactate accumulation during myocardial
ischemia. Circulation 89: 2283–2289, 1994.
Vegh A, Komori S, Szekeres L, and Parratt JR. Antiarrhythmic
effects of preconditioning in anaesthetised dogs and rats. Cardiovasc Res 26: 487– 495, 1992.
Vegh A, Papp JG, and Parratt JR. Prevention by dexamethasone
of the marked antiarrhythmic effects of preconditioning induced
20 h after rapid cardiac pacing. Br J Pharmacol 113: 1081–1082,
1994.
Physiol Rev • VOL
367. Vegh A, Szekeres L, and Parratt JR. Protective effects of preconditioning of the ischaemic myocardium involve cyclo-oxygenase products. Cardiovasc Res 24: 1020 –1023, 1990.
368. Verdouw PD, Gho BC, Koning MM, Schoemaker RG, and
Duncker DJ. Cardioprotection by ischemic and nonischemic myocardial stress and ischemia in remote organs. Implications for the
concept of ischemic preconditioning. Ann NY Acad Sci 793: 27– 42,
1996.
369. Von Ruecker AA, Han-Jeon B-G, Wild M, and Bidlingmaier F.
Protein kinase C involvement in lipid peroxidation and cell membrane damage induced by oxygen-based radicals in hepatocytes.
Biochem Biophys Res Commun 163: 836 – 842, 1989.
370. Wadsworth SA, Cavender DE, Beers SA, Lalan P, Schafer PH,
Malloy EA, Fahmy B, Olini GC, Davis JE, Pellegrino-Gensey
JL, Watcher MP, and Siekierka JJ. Rwj 67657, a potent, orally
active inhibitor of p38 mitogen-activated protein kinase. J Pharmacol Exp Ther 291: 680 – 687, 1999.
371. Walker DM, Marber MS, Walker JM, and Yellon DM. Preconditioning in isolated superfused rabbit papillary muscles. Am J
Physiol Heart Circ Physiol 266: H1534 –H1540, 1994.
372. Walsh RS, Daly JJ, Cohen MV, and Downey JM. Blockade of
both adenosine and alpha-adrenergic receptors is required to prevent hypoxic preconditioning in rabbit hearts (Abstract). J Am Coll
Cardiol 23: 396A, 1994.
373. Wang S, Cone J, and Liu Y. Dual roles of mitochondrial KATP
channels in diazoxide-mediated protection in isolated rabbit hearts.
Am J Physiol Heart Circ Physiol 280: H246 –H255, 2001.
374. Wang Y and Ashraf M. Activation of ␣1-adrenergic receptor during Ca2⫹ preconditioning elicits strong protection against Ca2⫹
overload injury via protein kinase C signaling pathway. J Mol Cell
Cardiol 30: 2423–2435, 1998.
375. Wang Y, Huang S, Sah VP, Ross J Jr, Heller Brown J, Han J,
and Chien KR. Cardiac muscle cell hypertrophy and apoptosis
induced by distinct members of the p38 mitogen-activated protein
kinase family. J Biol Chem 273: 2161–2168, 1998.
376. Wang Y, Takashi E, Xu M, Ayub A, and Ashraf M. Downregulation of protein kinase C inhibits activation of mitochondrial KATP
channels by diazoxide. Circulation 104: 85–90, 2001.
377. Weinbrenner C, Liu G-S, Cohen MV, and Downey JM. Phosphorylation of tyrosine 182 of p38 mitogen-activated protein kinase
correlates with the protection of preconditioning in the rabbit
heart. J Mol Cell Cardiol 29: 2383–2391, 1997.
378. Weinbrenner C, Liu G-S, Downey JM, and Cohen MV. Cyclosporine A limits myocardial infarct size even when administered
after onset of ischemia. Cardiovasc Res 38: 676 – 684, 1998.
379. Weselcouch EO, Baird AJ, Sleph P, and Grover GJ. Inhibition
of nitric oxide synthesis does not affect ischemic preconditioning
in isolated perfused rat hearts. Am J Physiol Heart Circ Physiol
268: H242–H249, 1995.
380. Weselcouch EO, Baird AJ, Sleph PG, Dzwonczyk S, Murray
HN, and Grover GJ. Endogenous catecholamines are not necessary for ischaemic preconditioning in the isolated perfused rat
heart. Cardiovasc Res 29: 126 –132, 1995.
381. Whalen DA Jr, Hamilton DG, Ganote CE, and Jennings RB.
Effect of a transient period of ischemia on myocardial cells. I.
Effects on cell volume regulation. Am J Pathol 74: 381–398, 1974.
382. Williams DO, Bass TA, Gerwirtz H, and Most MA. Adaptation
to the stress of tachycardia in patients with coronary artery disease: insight into the mechanism of the warm-up phenomenon.
Circulation 71: 687– 692, 1985.
383. Wilson S, Song W, Karoly K, Ravingerova T, Vegh A, Papp J,
Tomisawa S, Parratt JR, and Pyne NJ. Delayed cardioprotection
is associated with the sub-cellular relocalisation of ventricular
protein kinase C⑀, but not p42/44MAPK. Mol Cell Biochem 160/161:
225–230, 1996.
384. Woolfson RG, Patel VC, Neild GH, and Yellon DM. Inhibition of
nitric oxide synthesis reduces infarct size by an adenosine-dependent mechanism. Circulation 91: 1545–1551, 1995.
385. Xi L, Jarrett NC, Hess ML, and Kukreja RC. Essential role of
inducible nitric oxide synthase in monophosphoryl lipid A-induced
late cardioprotection. Circulation 99: 2157–2163, 1999.
386. Xiao X-H and Allen DG. Activity of the Na⫹/H⫹ exchanger is
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
351.
DEREK M. YELLON AND JAMES M. DOWNEY
MYOCARDIAL PRECONDITIONING
387.
388.
389.
390.
392.
393.
394.
395.
396.
397.
398.
399.
400.
Physiol Rev • VOL
401.
402.
403.
404.
405.
406.
407.
408.
409.
410.
411.
412.
413.
414.
Becker LB, Head CA, and Schumacker PT. Role of reactive
oxygen species in acetylcholine-induced preconditioning in cardiomyocytes. Am J Physiol Heart Circ Physiol 277: H2504 –H2509,
1999.
Yaoita H, Ogawa K, Maehara K, and Maruyama Y. Attenuation
of ischemia/reperfusion injury in rats by a caspase inhibitor. Circulation 97: 276 –281, 1998.
Yeghiazarians Y, Braunstein JB, Askari A, and Stone PH.
Unstable angina pectoris. N Engl J Med 342: 101–114, 2000.
Yellon DM, Alkhulaifi AM, and Pugsley WB. Preconditioning
the human myocardium. Lancet 342: 276 –277, 1993.
Yellon DM and Baxter GF. A “second window of protection” or
delayed preconditioning phenomenon: future horizons for myocardial protection? J Mol Cell Cardiol 27: 1023–1034, 1995.
Yellon DM and Baxter GF. Reperfusion injury revisited: is there
a role for growth factor signalling in limiting lethal reperfusion
injury. Trends Cardiovasc Med 9: 245–248, 1999.
Yellon DM and Latchman DS. Stress proteins and myocardial
protection. J Mol Cell Cardiol 24: 113–124, 1992.
Yin T, Sandhu G, Wolfgang CD, Burrier A, Webb RL, Rigel DF,
Hai T, and Whelan J. Tissue-specific pattern of stress kinase
activation in ischemic/reperfused heart and kidney. J Biol Chem
272: 19943–19950, 1997.
Ytrehus K, Liu Y, and Downey JM. Preconditioning protects
ischemic rabbit heart by protein kinase C activation. Am J Physiol
Heart Circ Physiol 266: H1145–H1152, 1994.
Ytrehus K, Liu Y, Tsuchida A, Miura T, Liu GS, Yang X-M,
Herbert D, Cohen MV, and Downey JM. Rat and rabbit heart
infarction: effects of anesthesia, perfusate, risk zone, and method
of infarct sizing. Am J Physiol Heart Circ Physiol 267: H2383–
H2390, 1994.
Yusuf S, Sleight P, Pogue J, Bosch J, Davies R, and Dagenais
G. Effects of an angiotensin-converting-enzyme inhibitor, ramipril,
on cardiovascular events in high-risk patients. The Heart Outcomes
Prevention Evaluation Study Investigators. N Engl J Med 342:
145–153, 2000.
Zahn R, Schiele R, Schneider S, Gitt AK, Seidl K, Bossaller C,
Schuler G, Gottwick M, Altmann E, Rosahl W, and Senges J.
The myocardial Registry Study Group. Effects of preinfarction
angina pectoris on outcome in patients with acute myocardial
infarction treated with primary angioplasty (results from the myocardial infarction registry). Am J Cardiol 87: 1– 6, 2001.
Zhao J, Renner O, Wightman L, Sugden PH, Stewart L, Miller
AD, Latchman DS, and Marber MS. The expression of constitutively active isotopes of protein kinase C to investigate preconditioning. J Biol Chem 273: 23072–23079, 1998.
Zhao T, Xi L, Chelliah J, Levasseur JE, and Kukreja RC.
Inducible nitric oxide synthase mediates delayed myocardial protection induced by activation of adenosine A(1) receptors: evidence from gene-knockout mice. Circulation 102: 902–907, 2000.
Zhu L, Fukuda S, Cordis G, Das DK, and Maulik N. Antiapoptotic protein survivin plays a significant role in tubular morphogenesis of human coronary arteriola endothelial cells by hypoxic preconditioning. FEBS Lett 508: 369 –374, 2001.
83 • OCTOBER 2003 •
www.prv.org
Downloaded from http://physrev.physiology.org/ by 10.220.33.4 on July 4, 2017
391.
critical to reperfusion damage and preconditioning in the isolated
rat heart. Cardiovasc Res 48: 244 –253, 2000.
Xuan Y-T, Tang X-L, Banerjee S, Takano H, Li RC, Han H, Qiu
Y, Li JJ, and Bolli R. Nuclear factor kappaB plays an essential
role in the late phase of preconditioning in conscious rabbits. Circ
Res 84: 1095, 1999.
Xuan Y-T, Tang X-L, Qiu Y, and Banerjee S. Biphasic response
of cardiac NO synthase to ischaemic preconditioning in conscious
rabbits. Am J Physiol Heart Circ Physiol 279: H2360 –H2371, 2000.
Yamagishi H, Akioka K, Hirata K, Sakanoue Y, Toda I, Yoshiyama M, Teragaki M, Takeuchi K, Yoshikawa J, and Ocji H.
Effects of preinfarction angina on myocardial injury in patients
with acute myocardial infarction: a study with resting 123I-BMIPP
and 201TI myocardial SPECT. J Nucl Med 41: 830 – 836, 2000.
Yamashita N, Hoshida S, Nishida M, Igarashi J, Taniguchi N,
Tada M, Kuzuya T, and Hori M. Heat shock-induced manganese
superoxide dismutase enhances the tolerance of cardiac myocytes
to hypoxia-reoxygenation injury. J Mol Cell Cardiol 29: 1805–1813,
1997.
Yamashita N, Hoshida S, Otsu K, Asahi M, Kuzuya T, and Hori
M. Involvement of cytokines in the second window of ischaemic
preconditioning. Br J Pharmacol 131: 415– 422, 2000.
Yamashita N, Hoshida S, Otsu K, Asahi M, Kuzuya T, and Hori
M. Exercise provides direct biphasic cardioprotection via manganese superoxide dismutase activation. J Exp Med 189: 1699 –1706,
1999.
Yamashita N, Hoshida S, Otsu K, Taniguchi N, Kuzuya T, and
Hori M. The involvement of cytokines in the second window of
ischaemic preconditioning. Br J Pharmacol 131: 415– 422, 2000.
Yamashita N, Hoshida S, Taniguchi N, Kuzuya T, and Hori M.
A “second window of protection” occurs 24 h after ischemic preconditioning in the rat heart. J Mol Cell Cardiol 30: 1181–1189,
1998.
Yamashita N, Hoshida S, Taniguchi N, Kuzuya T, and Hori M.
Whole-body hyperthermia provides biphasic cardioprotection
against ischemia/reperfusion injury in the rat. Circulation 98:
1414 –1421, 1998.
Yamashita N, Nishida M, Hoshida S, Kuzuya T, Hori M, Taniguchi N, Kamada T, and Tada M. Induction of manganese superoxide dismutase in rat cardiac myocytes increases tolerance to
hypoxia 24 hours after preconditioning. J Clin Invest 94: 2193–
2199, 1994.
Yang X-M, Baxter GF, Heads RJ, Yellon DM, Downey JM, and
Cohen MV. Infarct limitation of the second window of protection
in a conscious rabbit model. Cardiovasc Res 31: 777–783, 1996.
Yang X-M, Sato H, Downey JM, and Cohen MV. Protection of
ischemic preconditioning is dependent upon a critical timing sequence of protein kinase C activation. J Mol Cell Cardiol 29:
991–999, 1997.
Yao Z, McPherson BC, Liu H, Shao Z, Li C, Qin Y, Vanden Hoek
TL, Becker LB, and Schumacker PT. Signal transduction of
flumazenil-induced preconditioning in myocytes. Am J Physiol
Heart Circ Physiol 280: H1249 –H1255, 2001.
Yao Z, Tong J, Tan X, Li C, Shao Z, Kim WC, Vanden Hoek TL,
1151