Medical Research Sociefy
69. GASTRIC
INHIBITORY POLYPEPTIDE, C-PEPTIDE AND INSULIN: SECRETORY RESPONSES O F
HEALTHY VOLUNTEERS T O STANDARD CARBOHYDRATE LOADS
s. SYKES, L. M. MORGAN,s. M. HAMPTONAND V. MARKS
Division of Clinical Biochemisfry, Deparfment of Biochemistry,
Universify of Surrey, Guildford, Surrey .
The role of gastric inhibitory polypeptide (GIP) as an intestinal
augmenter of insulin release is now well recognized. There is
evidence from animal experiments that a number of carbohydrates apart from glucose can release GIP.
Five healthy, fasting, human subjects (21-31 years old) took
part in experiments to determine plasma GIP responses to
standard oral loads of glucose, galactose, fructose (50 g) and
sucrose (100 9). Peripheral plasma immunoreactive GIP
(IRGIP), insulin (IRI) and C-peptide (IRCP) were measured
before and 15, 30, 45, 60, 90 and 120 min after carbohydrate
ingestion on each of four occasions.
There was no significant change from basal levels in any of
the hormones measured after fructose (basal IRGIP, R = 193
pg/ml, s m = 13.2, n = 43; basal insulin, f = 8.1 munits/l,
SEM = 0.7, n = 38; basal IRCP, R = 1.88 ng/ml, SeM = 0.11,
n = 46). Each of the other three sugars produced rises in all of
the measured hormones and their time courses differed sign%cantly. Glucose and galactose produced the steepest rises in
IRGIP (Fig. 1) with highly significant changes from basal levels
at 45 min (respective values: R = 964 pg/ml, SEM = 116; x =
766 pg/ml, SEM = 182). Oral glucose, unlike galactose, produced
a sustained rise in plasma GIP (mean maximum value 1150
pg/ml & SEM 99); individual responses were, however, predominantly biphasic. The IRGIP responses to galactose were
monophasic with a peak at 30 min. IRGIP levels at 45,60,90
and 120 min after galactose were significantly lower than at
corresponding times after glucose. Compared with glucose,
sucrose-stimulated GIP release was delayed and IRGIP levels
were significantly lower at 15, 30 and 45 min. By 90 min,
however, peak IRGIP levels were similar to those produced
by glucose (R = 1116 pg/ml, SEM = 179 vs 1052 & 177).
Plasma insulin levels were not significantly different after oral
sucrose and glucose and both peaks were higher ( P < 0.025)
than after galactose. The IRCP response to all three stimulatory
carbohydrates showed a broad peak (plateau) between 30 and
90 min. Up to 30 min after ingestion there was no significant
difference between the IRCP responses to any carbohydrate. By
60 rnin through to 120 min the IRCP response to galactose was
less than to glucose (P < 0.05) but it was only after 120 min
that a significant difference was observed between galactose and
sucrose.
The data indicate that, in man, oral glucose, galactose and
sucrose, but not fructose, stimulate GIP, insulin and C-peptide
release. Since galactose intravenously does not stimulate insulin
1400
6oo 200 01
70. MEASUREMENT OF TRYPSIN CONCENTRATION
IN DUODENAL JUICE WITH A RADIOIMMUNOASSAY
c. E. RUBIOAND J. A.
G. LAKE-BAKAAR,S. MCKAVANAGH,
SUMMEWIELD
Department of Medicine, Royal Free Hospital, London
Trypsin output in duodenal aspirate after pancreatic stimulation
with either a Lundh meal or cholecystokinin-pancreozymin
(CCK-PZ) and secretin remains a standard test of pancreatic
function. However, the usual method of trypsin estimation,
based on enzymatic hydrolysis of the substrate p-tosyl-Larginine methyl ester/HCI (TAME) has several disadvantages,
including autodegradation of the enzyme, which precludes
storage before estimation.
A radioimmunoassay (RIA) has been described for the
estimation of trypsin even in the presence of inhibitors such as
Trasylol. The trypsin concentration in duodenal aspirate has
been determined by RIA in a total of 25 estimations and
compared with the enzymatic method. The effect of Trasylol on
the stability of trypsin in duodenal aspirate stored at -70°C was
also studied.
Enzymatic activity correlated well with the mass of frypsin
obtained by RIA (P < 0.005, Student's t-test). N o crossreactivity was shown with Trasylol. Storage of duodenal
aspirate led to rapid loss of trypsin (mean 9.9%, range 6.3-19%
at 4 weeks). This was completely prevented by the addition of
Trasylol (P < 0.05, Student's paired I-test).
We conclude that RIA determination of duodenal juice
trypsin concentration is a useful alternative method to enzymatic analysis and should be performed whenever prior
storage of the enzyme is necessary, since autodegradation can
be completely prevented with Trasylol.
71. THE SOLUBLE PROTEIN CONTENT O F SPUTUM
IN PATIENTS WITH BRONCHITIS
EFFECT O F RECENT INFECTION
AND
THE
M. D. MISTRY,R. A. STOCKLEY,D. BURNEITAND A. R.
BRADWELL
G'uco
T
ac
3
E
secretion it is possible that the rise in both IRI and IRCP after
oral galactose is GIP-mediated. The rise in plasma GIP after
sucrose was delayed when compared with that produced by
glucose, but this was not reflected in the speed and magnitude of
the rises. in plasma IRI and IRCP. This must throw doubt on
the unique importance of GIP as the intestinal mediator of
insulin release. The reason for the delayed plasma GIP response
to sucrose is not known but may be related to the need to
hydrolyse sucrose to glucose and fructose in the intestinal brush
border.
Departmenfs of Immunology (Immunodiagnosfic Research
Laboratory) and Medicine, University of Birmingham, Birmingham
-
1000 -
2 3 ~
,
T
-
T
r
-
Galactose
'Fructose
I
0
I
I
I
30
I
60
Time (min)
FIG1.
I
I
90
I
I
120
There has been much recent interest in the nature and function
of bronchial secretions in the protection of the lung. The sol
phase of these secretions contains many proteins, but their role
and origin is far from clear.
The soluble protein content of normal secretions is low. The
majority is thought to be derived from serum as a result of
capillary transudation, although IgA is probably produced
locally within the lung (Wan, Martin & Sharp, 1977, American
Review of Respiratory Disease, 116,25).
Patients with chronic bronchitis have increased production of
bronchial secretions and expectorate a large proportion as
sputum. There have been few studies of the nature and origin of
the bronchial secretions in these patients. Ryley & Brogan
(1973, Journal of Clinical Pathology, 26, 852) presented
evidence suggesting a local production of q-antichymotrypsin
(a protease inhibitor) as well as IgA although their methods
2 4 ~
Medical Research Society
TABLE1. Sputumlserum protein ratios
Group A = non-infected patients; Group B = patients with
recent infection. Mean values _+ SEM are shown. n = number of
patients studied.
10’ x Mean ratio
Protein
Group A (n = 17) Group B (n = 8)
c,
kA
$-Macroglobulin
1gM
73. TRANSMISSION O F FLOW PULSES THROUGH
THE CANINE LUNG
B. RAJAGOPALAN,
E. HYELLAND G.
DE J.
LEE
Department of Cardiology, The Radclire Infirmary, Oxford
~~
Orosomucoid
a,-Antitrypsin
Albumin
Transferrin
a,-Antichymotrypsin
Caeruloplasmin
Haptoglobin
IgG
remaining myocardium, may also determine left ventricular
function after AMI.
0.521 f 0.065
1.153 ? 0.131
0.831 f 0.832
0.828 t 0.091
3.138 0.615
0.639 f 0.647
0.336 t 0.051
1.154 fO.111
0.985 5 0.137
12.122k 1.627
0.729 f 0,592
1.936 f 0.369
3.887 f 1.633
5.619 1.816
5.878 2.550
5.604 f 2.263
8.018 2 2.238
1.398 f 0.336
2.673 t 0.946
4.779 t 1.563
3.889 f 1.453
17.895 f 3.326
2.359 t 0.914
7.434 f 2.368
+
were inaccurate. A recent study by Tegener (1978, Acta
Otolaryngology, 85,282) failed to confirm this finding in normal
subjects.
We therefore studied the protein content of the sol phase of
sputum and serum in subjects with chronic bronchitis. Seventeen
subjects were studied when well and eight after a chest infection.
The results were expressed as mean sputum to serum ratio for
12 proteins (Table 1).
The sputum to serum ratios in the non-infected group were
higher for IgA, IgM and a,-antichymotrypsin (P < 0.01) than
would be predicted by simple diffusion from serum. This
suggests active transport, local production or local retention of
these proteins to or within the bronchial tree. The remaining
proteins appear to be derived from serum by simple diffusion
and their sputum to serum ratio was higher after recent infection
(P < 0.01), probably as a result of inflammation. The
implications of these findings will be discussed.
72. RELATIONSHIP BETWEEN INFARCT SIZE AND
THE P-WAVE TERMINAL FORCE IN ACUTE MYOCARDIAL INFARCTION
s. POHJOLA, s. YUSUF, R. LOPEZAND A. MADDISON
Department of Cardiovascular Medicine.
Irlfirmary, Ogord
The Radcliffe
A negative P-wave terminal force (PTF) on the ECG (V,) is
always abnormal. It has previously been shown to reflect
quantitatively a rise in left ventricular end diastolic pressure and
reduced long-term survival in patients with acute myocardial
infarction (AMI). In the present study, the PTF on the ECG 2
weeks after infarction was compared with infarct size (IS)
estimated from cumulative MB-CPK over the first 72 h after
pain in 45 patients with AMl.
43 of 45 patients showed a negative PTF on the discharge
ECG (abnormal). The mean PTF in patients with large infarcts
0.1337 ps
(cumulative MB-CPK 2 208 i.u./l) was -0.02231
and was significantly more negative than in patients with smaller
infarcts (MB-CPK < 208 i d l ) , in whom the PTF was -0.1337
+O-0022 (P < 0.02; Student’s I-test). In addition, a PTF -0.03
ps or more negative was found in only two of 21 patients
with small infarcts as compared to 10 of 24 patients with large
infarcts.
Correlation between IS and PTF was also significant when
compared as continuous variables ( r = 0.368; P < 0.05).
In conclusion, the degree of left ventricular failure assessed
non-invasively by the PTF is related to the size of infarction.
However, the weakness of this relationship suggests that factors
other than IS, e.g. previous ischaemia or fibrosis in the
Measurements of transmission of flow or pressure waves are
useful in analysing the properties of vascular beds. We have
measured pulsatile blood flow and pressure in the pulmonary
artery and vein and pulsatile blood flow in the capillaries of
anaesthetized dogs. The Fourier harmonics of the pressure and
flow pulses were computed and the impedance of the lobe was
calculated as the ratio of each harmonic of pressure to that of
flow. The transmission of flow pulses from the pulmonary artery
to the capillaries and from the capillaries to the veins for each
harmonic were calculated as a ratio of the output to the input.
Other experiments (Friend, Lee, Rajagopolan & Stallard,
1977, Journal of Physiology, London, 269,52~)had shown that
the pulsatile waveform of flow in the pulmonary veins was
largely determined by left atrial pressure changes, and components due to transmission of flow from the capillaries could
not be identified in the intact circulation. In order to determine
transmission to the veins, the left lower lobe pulmonary vein
was connected to a constant-pressure reservoir with no change
in mean flow level. The added impedance of the tubing and
reservoir was allowed for by using the techniques described by
Maloney, Bergel, Glazier, Hughes & West (1968, Circulation
Research, 23, 11).
Measurements of transmission from the artery to the veins
were made at transpulmonary pressures (TPP) of 5 , 10 and 15
cm water but capillary blood flow could only be measured at 35 cm water TPP. The transmission of flow from the arteries to
the capillaries was 69% at 1 Hz, falling to 46% at 5 Hz. The
transmission from the capillary to the veins was, however, much
more sensitive to frequency, being 42% at 1 Hz and only 10% at
5 Hz. Thus only 28% of the flow harmonic in the pulmonary
artery at I Hz reached the pulmonary veins and this fell to 46% at 5 Hz. The transmission from the arteries to the veins was
17% at 1 Hz at a TPP of 5 cm water, and this fell to 14% when
the lungs were inflated to 10 cm water TPP and to 8.6% at 15
cm water TPP. Transmission at higher frequencies was also
progressively attenuated. Changes in the outflow venous
pressure produced by altering the height of the reservoir did not
alter the transmission ratios.
Thus only a small fraction of the pulsatile flow from the
pulmonary artery is transmitted to the veins, and this is further
reduced by lung inflation, the attenuation probably occurring
mainly in the small alveolar vessels.
74. INHIBITION BY PHENOLS O F SODIUM-POTASSIUM STIMULATED ADENOSINE TRIPHOSPHATASE
E. N. WARDLE
Department of Medicine, Royal Victoria Irlfirmary, Newcastle
upon Tyne
Free and conjugated phenols and phenolic acids accumulate in
uraemia and hepatic failure and may play a role in the genesis of
coma. We (Turner & Wardle, 1978, Clinical Science and
Molecular Medicine, 55, 3 7 ~ )have described their effect in
depressing cyclic AMP formation in brain. This report concerns
the depressant effect of phenol and its glucuronide, cresol,
phenylacetic acid and mandelic acid on the Na-K-stimulated
ATPase of erythrocyte membranes, brain microsomal fraction
and platelet membranes. Assay of ATPase was performed by a
sensitive colorimetric technique (Muszbeck, 1977, Analytical
Biochemistry, 77, 286) and by radiometric assay (Bais, 1975,
Analytical Biochemistry, 63,27 1).