BIOLOGY
OF REPRODUCTION
591-598
17,
(1977)
Autorhythmic
Contractions
of the Postnatal
Capsule and its Response to Prostaglandins,
Acetyicholine
MARK
A.
MITCHELL
and
ROD
Department
of Biology,
Rabbit Testicular
Epinephrine
and
R.
SEELEY
Idaho
State
University,
Pocatello,
Idaho
83209
ABSTRACT
Autorhythmic
contractions
of the rabbit
preparations
from animals 2 to 18 weeks
prostaghandin
(PG)F,
PGE1,
Epinephrine,
dose-response
in vivo
and
curves
plotted.
in vitro
throughout
The
data
testicular
capsule were measured in vivo and in vitro
of age. The response of the testicular
preparations
and Acetylcholine
that spontaneous
indicate
(ACH)
was
autorhythmic
determined
contractions
in
to
and log
occur
postnatal
development,
that the amplitude
of the contractions
increases while the mass of the testis and the thickness
of the testicular
capsule increases, and that
the relative response to PGF2a, epinephrine
and ACH remains constant
throughout
postnatal
development.
However,
the response of the testicular
capsule to PGE1 became progressively
more inhibitory
at higher concentrations
throughout
postnatal
development,
which may be indicative
of
the development
of adenylcyclase
activity
within the testicular
tissues.
INTRODUCTION
The
tunica
rabbit
albuginea
testicular
of
capsule
the
human,
contains
rat
and
cells
as a major
component
(Davis
et a!.,
1970;
Davis
et a!., 1971).
The
autorhythmic
contractions
generated
by these cells may facili-
sperm
transport
and
of blood
and lymph
al.,
1971;
Langford
neither
the
function
the
circulation
(Davis
et a!., 1970; Davis et
et a!.,
1973).
However,
regulatory
of
testicular
mechanisms
are
contractions
nor
the
have
the
and
generated
neural
muscle.
ergic
sule
conflicting
control
The
pharmacological
data
of testicular
presence
of
nerve terminals
of the
rat has
al.,
1972a),
and
direct
respect
and
to
smooth
cholin-
the testicular
reported
(Bell
McLean,
1973).
In addition,
of nerves
to the testes
of
creased
testicular
capsular
et
with
capsular
adrenergic
within
been
studies
capand
appears
unlikely,
plays
regulation
and
when
muscarinic
stimulated,
amplitude,
or
tonus
demonstrated
(Rikimaru
agents
but
Electrical
contractions
portant
modulation
lar
role
in the
capsular
dogenous
contractions.
in the
regulation
of the
PGF3a,
rabbit
and
Seeley
others
stimulation
(PG’s)
et al.,
exceeded
this
of
1971;
1974).
may
5 ng/ml
contractions
PGE1,
PGE2,
the amplitude,
Hargrove
et
50
ng/ml,
(Seeley
et al., 1974).
Subthreshold
tions
of PG’s also potentiated
the
Accepted
Received
testicular
epinephrine,
June 22, 1977.
March 18, 1977.
591
preparations
ACH,
to other
histamine,
in
in
al.,
PGE1
rabbit
vitro
1973a;
and
less stimulatory
testicular
bathing
and
en-
participate
contractions
in vivo
and
However,
testicu-
respect,
of smooth-muscle
testicular
capsule.
PGF2c
increased
or tonus
preparations
et a!.,
of rabbit
In
prostaglandins
frequency,
testicular
stimulation
not
capsular
local
hormonal
mechanisms
mechanisms
may play an im-
ganglionic
1972b).
of
that
humoral
or
rather
than neural
became
progressively
concentrations
in the
blocking
that
in modulat-
for the rabbit
testicular
capet al., 1972a,
b). It is possible
(Johnson
et al.,
role
cholinergic
receptors
which,
yield
an increased
frequency,
of rabbit
and human
testicular
preparations
elicited
contractions
that were blocked
by some
(Rikimaru
therefore,
a major
ing testicular
capsular
contractions
in rabbits,
but it may be an important
factor
in other species. However,
a predominance
of a-adrenergic
direct
stimulation
dogs resulted
in inmotility
(Rikimaru
electrical
It
neural
was
sule
completely
understood.
Histochemical
testicular
nerves
in rabbits,
however,
no observable
response
(Hargrove
et al.,
1976).
smooth-mus-
cle
tate
of the
yielded
PGE2
as their
medium
respectively
concentraresponse
of
agonists
such as
and
serotonin
MITCHELL
592
(Hargrove
and may,
the
like
et a!., 1973a;
Hargrove
et a!., 1975)
therefore,
modulate
the response
of
capsule
to
compounds
nates
of
rat
other
agonists.
were extracted
and
rabbit
taneously
contracting
In
et al.,
bathing
in vivo
smooth
muscle
mature
have
domestic
velopment
of rabbit
poorly
understood,
mental
characteristics
tive
system
reported
creased
have
et al., 1973b).
of rabbit
testic-
been
performed
rabbits.
of
age; sexual
de-
contractility
is
other
developrabbit
reproduc-
investigated.
maturity
on
Postnatal
It has been
that
the
mean
testicular
from
0.24 g at 6 weeks
to
weeks
(Car-
rabbit
in vitro
and
testicular
although
of the
been
tissue
1971;
Seeley
et
media of spon-
testicular
preparations
(Hargrove
Essentially
all investigations
sexually
addition,
PGfrom
homoge-
testicular
penter
1971;
Carpenter
al., 1973)
and from
the
ular
AND
weight
in2.42 g at 18
as defined
by tes-
ticular,
seminal
vesicular,
and epididymal
sperm
counts
was attained
by 23 weeks of age; and total androgen
secretion
for the perfused
testis
and
epididymis
weeks
of age
reached
a maximum
at 18
(Chubb
et a!., 1976).
These data
indicate
that the rabbit
testis attains
adult functions between
18 and 23 weeks of age.
Measurements
of testicular
capsular
contractions
throughout
postnatal
development
may
generate
data that allow greater
insight
into the
function
and regulation
of testicular
capsular
smooth
muscle.
The purpose
vestigation
is to determine
testicular
out
age),
the
frequency
testicular
teristics
exists
and
postnatal
infor
through-
(2-18
weeks
changes
occur
amplitude
of
of
in
contractions
development,
to compare
contractions
with
histological
of the testicular
capsule,
and
characto deter-
if log dose-response
(LDR)
curves
generin response
to PGE1,
PGF2a,
ACH,
and
epinephrine
action
contractions
postnatal
development
to determine
if obvious
throughout
mine
ated
capsular
of the present
if the potential
suggest
a constant
throughout
postnatal
MATERIALS
AND
mechanism
of
development.
METHODS
Domestic
rabbits (Oryctolagus
cuniculus)
of mixed
breeds were obtained
from a local source and raised to
the desired age in a small animal laboratory.
The rabbits were exposed
to the natural
photoperiod
and a
temperature
range of 20 to 30#{176}C.
Rabbit chow (Purina
Co.) and water were provided ad libitum.
One testis was excised from each of 5 animals
from
each of the following
age groups:
2, 4, 6, 8, 10, 12,
14, 16, 18, and 20 weeks of age. The testes were fixed
in Baker’s formalin,
dehydrated,
embedded
in parsplast plus (Sherwood
Medical
Industries),
and pre-
SEELEY
pared for light microscopic
examination
using standard histological
techniques.
All sections
were 7 i
thick
and the slides were stained with hematoxylin
and eosin, Verhoff’s
elastin,
or Masson’s
trichrome
stain (Humason,
1972). Observations
included
measuring the thickness
of the testicular
capsule (tunics vaginalis viscera + tunics albuginea),
the diameter
of the
seminiferous
tubules,
and the number
of spermatids
exhibiting
condensed,
elongated
nuclei
and flagella
(maturation
phase spermatids)
within the seminiferous
tubules.
Five slides were examined
from each testis and
measurements
of 5 separate sections for anterior
and
lateral capsular thickness
using a calibrated
ocular micrometer
were made on each slide. The diameter
of 5
seminiferous
tubules from each section examined
was
also determined.
Only those tubules
that were obviously not oblique
sections were included
in the measurements
of the seminiferous
tubule
diameter.
All
sections examined
were inspected
for the presence of
maturation
phase spermatids
within
the seminiferous
tubules.
When they were present,
the number
was
counted
in 5 seminiferous
tubules from each section
examined.
In vivo
testicular
capsular contractions
were measured by anesthetizing
the rabbits with sodium pentobarbital
(Sigma
Chem.
Co., 30 to 45 mg/kg)
administered intravenously
or urethane
(Nutritional
Biochem.
Co., 2 to 4 g/kg) administered
intraperitoneally.
The
anesthetics
were
dissolved
in Tyrode’s
solution.
Surgi-
cal preparation
and recording
of in vivo testicular
preparations
were performed
according
to a modified
method of Seeley et al. (1973).
The anesthetized
animals were restrained
in a supine position,
an incision
was made in the wall of the scrotal sac to expose the
testis. Silk thread (5-0, Ethicon,
Inc.) was ligated to
the inferior
and superior
poles of the testis, the testis
was drawn
through
an opening
approximately
the
diameter
of the testis in the center of a rectangular
plastic
membrane,
and then through
a tube and cork
assembly which was affixed to a water-jacketed
muscle
warmer.
The
scrotal
sac and plastic-membrane
were
pulled
upward
around
the tubular
portion
of the
muscle warmer
and tied with copper wire. The silk
thread
attached
to the inferior
pole of the testis was
anchored
to the base of the muscle warmer
and the
silk thread attached
to the superior
pole of the testis
was connected
to a microdisplacement
myograph
transducer
(Model
F-SO, Narco Biosystem,
Inc.) or a
force displacement
transducer
(Model
FR1OC, Grass
Instrument
Co.).
Sufficient
tension
(0.5-1.Og)
was
applied
to each testes in order to suspend
it in the
muscle warmer and was constant
throughout
the experimental
period.
Isometric
contractions
were recorded using a physiograph
(Mode!
DMP-4B,
Narco
Biosystems,
Inc.) or an ink writing oscillograph
(Model
H925-P, Grass Instrument
Co.).
The testes were suspended in Tyrode’s
solution
maintained
at 35#{176}C
and
agonists were added directly to the bathing medium.
In vitro
testicular
capsular
contractions
were recorded by excising the contralateral
testis of animals
used for in vivo experiments.
The epididymides
were
removed and the testes were then suspended
in oxygenated
Tyrode’s
solution
maintained
at 35#{176}C.Silk
thread was ligated to either pole of the testis and recordings were made as described above.
Spontaneous
contractions
were
monitored
for
20
POSTNATAL
DEVELOPMENT
OF
TESTICULAR
CAPSULAR
MOTILITY
593
TABLE
1. Mean maximum
amplitude
of spontaneous
contractions
for in vivo and in vitro
preparations
rabbit testes ages 2 to 18 weeks and mean testicular
weight of rabbit testes 2 to 20 weeks of age.
In vivo
(N=5)
gram force
contraction
Age
(weeks)
2
4
.
of
In vitro
(N=5)
Testicular
gram force
contraction
SEM)
(Mean
±
SEM)
weight
(grams)
(Mean
0.011
0.006
0.026
0.021
±
0.008
0.42
±
0.003
±
±
0.018
0.57
±
0.007
(12)
(8)
(Mean
±
0.049
0.03 1
±
SEM)
±
0.035
±
0.031
0.137
±
0.032
0.66
±
0.04
(10)
8
10
0.082
0.126
±
0024
0.085
±
0.018
±
0.014
(13)
±
0.145
±
0.032
±
0.054
(13)
12
0.381
±
0.349
±
0.135
1.00
±
0.075
14
0.101
±
0.036
0.288
0.064
0.53
0.78
0.290
±
0.138
0.97
±
0.08
16
0.101
±
0.019
0.210
±
0.245
1.66
±
0.105
(12)
(9)
(11)
18
20
0.294
±
0.109
0.503
±
0.075
±
..
.
2.23
2.83
0.123
0.248
(14)
(8)
6
.
aNumber
..
in parentheses
.
denotes
number
..
.
.
.
±
of testes.
mm prior to experimentation.
The amplitude
of spontaneous and induced contractions
were determined
by
measuring
deviations
from the established
baseline.
The
maximum
response
generated
within
a 5 min
period
was routinely
measured.
The agonists
(PGE1
and PGF,
Upjohn
Co.; acethylcholine
chloride,
Baker Chem. Co.; and L-epinephrine,
Sigma Chem. Co.)
were administered
directly
to the bathing medium
of
in vivo and in vitro
preparations.
All preparations
were
washed
with
prewarmed
Tyrode’s
solution
a minimum
of 2 times
before
the addition
of the first test compound
and between
the application
of each test compound.
Tyrode’s
solution
was the vehicle
for ACH
and
Epinephrine
and 100 percent
ethanol
was the vehicle
for the PG’s previously
described
(Seeley
et al., 1973).
LDR
curves were developed
for the response of the
in vitro
testicular
preparations
to PGE1, PGF20, ACH
and epinephrine
for the following
age groups:
2-4,
6-
8, 10-12,14-16,
and 18 weeks.
Analysis
of variance
coupled
with Student
Newman-Keul’s
test were used for statistical
analysis of in
vivo and in vitro
spontaneous
autorhythmic
contractions and the Group
comparison
“t”
test was used for
statistical
analysis of LDR
data (Sokal
et a!., 1969).
Significance
was accepted
with P<0.05.
sections
of seminiferous
16 weeks
of age and
tween
16 and
tubules
increased
18 weeks
Spontaneous
of age
in
from
animals
number
be-
(Fig.
1).
autorhythmic
contractions
were
generated
by some
in vivo
preparations
from
each age group
percentage
2,4,6,8,
that
80,
exhibited
50, 60,
The
60,
spontaneous
40, 100
of
in
8,
10,
percentage
animals
of
of in vivo preparations
10, 12, 14, 16, and
2,
age
100,
4,
that
25,
6,
exhibited
80,
and in
tested.
from
animals
18 weeks
of age
motility
and
was 29, 75,
respectively.
100
vitro
57,
80,
from
preparations
12,
14,
16
and
spontaneous
83,
vitro
The
80,
18
weeks
motility
100
and
was
100,
re-
spectively.
025
Zcr.ao’
,h606.,,
0
thICk,t
CIO
020
(ait.tIal
11,06,1)
t1221,
324
sptc,lozoa/06it
->,
dI*
126
RESULTS
w.,mot,zoo/5bM
-.
015
A gradual
increase
in testicular
weight
from
a mean of 0.42 g at 2 weeks of age to a mean of
0.97
id
g at 14 weeks
was followed
increase
from
14 weeks
to
at 20
lar
weeks
thickness
and
increased
The
of age (Table
during
increased
appeared
plasia
mass
Mature
of
of
same
be
due
of
to
connective
the
cells
tissue
were
of
(Fig.
testicular
within
first
g
diameter
period
and
lihhhhHHfl
rap-
2.83
capsu-
tubule
time
hypertrophy
smooth-muscle
spermatozoa
a more
Testicular
seminiferous
the
thickness
to
1).
by
a mean
2
1).
4
6
8
10
12
4
6
8
20
206
capsule
and
an
the
observed
hyper-
increased
capsule.
in cross
FIG. 1. Mean capsular
thickness,
seminiferous
tubule diameter,
and presence of mature spermatozoa
in
seminiferous
tubules in testes from animals between 2
and 20 weeks of age. Each mean represent
25 observations
from
each
of
5 animals
for
each
age group.
MITCHELL
594
TABLE
2.
from
animals
Mean
frequency
2 to 18 weeks
of spontaneous
of age. (Mean
contractions
SEM).
±
In
AND
SEELEY
for
in
and
vivo
preparations
in vitro
of rabbit
testes
In vitro
vivo
Frequency
of
spontaneous
Frequency
of
spontaneous
Age
(weeks)
contractionsa
(Mean
± SEM)
contractionsa
(Mean
± SEM)
2
4
6
8
10
0.43
1.50
2.20
1.00
2.60
2.00
2.20
3.20
3.00
12
14
16
18
aNumber
per
bNumber
in parentheses
The
ated
each
mean
0.298
0.50
(7)b
3.25
1.00
±
(4)
±
1.113
(5)
4.20
±
±
0.510
(6)
±
1.077
0.836
(5)
(5)
1.355
0.201
0.219
(5)
(5)
(7)
2.50
2.86
2.60
2.60
3.50
4.00
±
±
±
±
±
±
in
denotes
frequency
the
of
number
mean
contractions
frequency
cause
tions,
of the large
the validity
variation
of the
tioned.
cy of
No obvious
contractions
trends
were
preparations
from
Large
variations
gener-
of
contractions
between
trend
may
preparabe ques-
was
possible,
tension
exact.
the
in
by
from
from
weeks
mean
of age
maximum
exceeds
other
that
age
tude
of
from
animals
significantly
of
g
contractions
2,
4,
(P<0.05)
the
of age. However,
tions
from
animals
age
did
The
erated
in
by
g to
mean
maximum
neous
differ
(7)
0.872
(5)
±
0.872
(5)
±
0.343
(6)
±
0.800
(9)
amplitude
testicular
18
g,
of
age
from
increased
respectively
from
(Table
amplitude
contractions
gen-
preparations
weeks
0.503
significantly
maximum
vitro
2 and
0.026
not
mean
in
of
generated
1).
vitro
by
animals
mean
in
6 weeks
testicular
8, 10,
12
all
ampli-
preparations
vivo
of
animals
age
10 weeks
(P<0.05)
from
ated
in
The
sponta-
preparations
the
following
16,
and
capsule
PGF2,
18
weeks
differed
12 weeks
capsular
contrac12, 14, 16 and
18
3.4
i
LDR
and
ACH
has
and
LDR
were
1.45
for
,u M,
the
was
ACH
were
PGF2a,
sigepi-
2.8 u M and
Although
(P<0.5)
14-
of
curves
ED5O’s
for
10-12,
response
each
its characteristic
difference
(Figs.
2-4).
agonists
may,
The
(PGF2a,
therefore,
constant
be
throughout
Changes
rations
the
The
in
ACH
set
form,
existed
of
no sigbetween
on the LDR
curves for the same concenof each agonist
among
the age groups
tested
the
and
The
gener-
measured
6-8,
age.
respectively.
curves
points
tration
2-4,
of
and
2, 4,
tonus
were
epinephrine,
shape.
M,
nificant
capsular
epinephrine,
PGF2a,
gener-
animals
age differed
significantly
18 weeks of age.
groups:
in
from
preparations
to
to
contractions
testicular
in vitro
by
of
animals
Increases
nephrine,
with
a
g which
from
maximum
6, 8, and
moid
of 2 to 18
from
of spontaneous
vitro preparations
in
dose-dependent,
g in preparaages
by preparations
from
not
amplitude
contractions
of 0.381
of
and
was
contractions
0.294
to
exhibited
amplitude
The
of
(P<0.05).
response
a constant
maximum
1). Preparations
generated
between
warmers
preparations
between
groups.
ranged
muscle
spontaneous
0.049
(Table
all
mean
vivo
animals
weeks
0.858
±
amplitude
ated by
application
to
However,
increased
tions
and
(0.5-1.Og)
generated
±
2 to 18 weeks of age.
amplitude
of contrac-
animals
in the
all testes,
which
2.83
g, within
the
g and
(5)
(6)
in the mean frequenexhibited
by in vitro
for
not
1.238
0.343
from
animals
2 and 4 weeks
old differed
significantly
(P<0.05)
from
preparations
from
animals 12 weeks of age. Also, the mean maximum
within
and between
the age
groups
in
vivo
and
in vitro.
Some
variability
may be the product
of the recording
technique;
establishment
of the same three dimensional
ar0.42
weeks
animals
occurred
rangement
±
of animals.
exhibits
by in vivo preparations
from
animals
2
to 18 weeks
of age may be noted.
However,
be-
tions
(8)
(4)
minute.
by in vivo
and
in vitro
preparations
for
age group
is presented
in Table
2. An in-
crease
0.163
1.00
±
from
in
tonus
rabbits
LDR
curves
for
epinephrine,
considered
to
postnatal
of
2-4,
in
and
be
each
ACH)
essentially
development.
vitro
testicular
6-8,
10-12,
prepa14-16,
of
POSTNATAL
DEVELOPMENT
OF
TESTICULAR
CAPSULAR
595
MOTILITY
I00#{149}
tOo
U)
0
D
1,)
0
a
a
50’
I-J
0.
4
4
a
2-4
WEEKS
6-8 WEEKS
10-12 WEEKS----14-16 WEEKS
I8WEEKS---#{149}--
0
>6
4
a
a
a
-
0
is
-50
-100
O2%jM
2jM
CONCENTRATION
OF
2iM
and 18 weeks
of age in response
to PGE1,
plotted
as LDR
curves
(Fig.
5). At 0.029
the
response
groups
tested.
and
more
inhibitory
indicating
were
.u M
was an increase
in tonus
in all
A general
decrease
in tonus
was
with
increasing
concentrations
of
j.z M PGE1
became
progressively
as the animals
increased
in age
29
a trend
in the
response
68pM
68jiM
OF ACETYLCHOUNE
OO68jIt
O68,M
CONCENTRATION
PGF2
FIG. 2. LDR curves for PGF20
on in vitro
rabbit
testicular
preparations
from animals 2-4,
6-8,
1012, 14-16,
and 18 weeks of age. The mean % maximum amplitude
is plotted
and N
5 for each age
group.
PGE1,
-so
WEEKS---------WEEKS
WEEKS--WE EKS
WEEKS---
-100
.
0.029pM
observed
2-4
6-8
10-12
14-16
8
a
of the in vitro
FIG.
4.
curves
for acetylcholmne
on in vitro
preparations
from animals 2-4, 6-8,
and
18 weeks of age. The mean %
amplitude
is plotted
and N = 5 for each age
LDR
rabbit testicular
10-12,
14-16,
maximum
group.
testicular
capsule
to 29 j.tM PGE1.
generated
by in vitro
preparations
2-4
weeks
of age to 29 .tM PGE1
nificantly
age.
(P<0.05)
The
response
10-12
weeks
fered
significantly
other
age
00
from
of
of
to
animals
differed
from
sig-
18 weeks
from
0.029
(P<0.05)
response
from
animals
preparations
age
The
.tM
of
animals
PGE1
animals
difof all
groups.
00
/
/
-..
-‘-‘I,
I
,4
50
0
I-
a
4
0’
‘
‘
i
>6
4
..
10-12 WEEKS--14-16 WEEKS
I8WEEKS-
4
a
is
a
2-4 WEEKS
6-8WEEKS
‘‘
-50’
a
a
a
is
-50
6-8
WEEKS
10-12 WEEKS--....
14-16 WEEKS
I8WEEKS-.------
-
I
100
0,056jM
O,56M
CONCENTRATION
5.6iM
OF
3.
O.O29
56pM
EPINEPHRINE
curves for epinephrine
on in vitro
rabbit testicular
preparations
from animals 2-4, 6-8,
10-12,
14-16,
and 18 weeks of age. The mean %
maximum
amplitude
is plotted
and N = 5 for each age
group.
0
‘C
4
-tOO
FIG.
50
0
I-J
a-
Z2’:T.
1a-
a
a
0’
CONCENTRATION
LDR
FIG.
testicular
12,
mum
group.
14-16
5. LDR
curves for
preparations
from
and
amplitude
9pM
O.2jM
18
weeks
is plotted
OF
PGE1
29pM
POE1
on in vitro
rabbit
2-4,
6-8,
10of age. The mean % maxiand N = 5 for each age
animals
MITCHELL
596
AND
DISCUSSION
That
rabbit
tions
under
(Table
capsular
in
2)
capsular
in
and
vivo
suggests
the
when
isotonically
or
Langford,
tractions
from
and
rabbit
the
2
measured
under
in vivo
(Table
1),
thickness
ing
of
the
the
same
creased
tions
during
postnatal
degree,
be
contractile
The
2 and
trends
weeks
the
under
(Table
2).
vivo
in
latory
mechanisms
mides
in
tractions
under
the
that
in
vivo
of
the
large
variability
tions
suggests
vitro
and
due
vivo
indicated
in
vitro
in vitro
presence
intact
influenced
the
frequency
differences
preparations
is
con-
may
simply
be
Spontaneous
the
autorhythmic
rabbit
testicular
and
vivo
mechanism
tions
are
smooth
PGE1,
1974;
epinephrine
However,
with
of
an
contraction
PGE2,
PGF1,
Johnson
et
1973a,
b;
1973a,
b; Rikimaru
Hargrove
the
increase
to
tonus
capsule
epinephrine,
and PGF2a
(Seeley
a!., 1971;
Hargrove
et
eta!.,
al.,
1975;
1972;
Seeley
Hargrove
constant
ampliACH,
et al.,
et al.,
et
al.,
eta!.,
the
response
from
the
the
to
potentiate
b).
that
the
to
addi-
condimediate
to
be
postnatal
of in vitro
ACH,
present
develop-
testicular
prepa-
2 to 18 weeks of age using
and PGF2a
as agonists
rewere
each
of
not
the
the age groups
tested
suggest
that receptors
a response
are
tare
throughout
In
that
which
are
present
as early
mechanisms
other
synthetase
in a reduced
capsule
for
tested
the
to
in vivo
curves
at least
1977).
capsule
LDR
agonists
capsule
testicu-
Dray,
1973a,
testhan
and
different
throughout
These
data
rat
greater
appear
be
PGF1a,
tissue.
In
reported
that
from
throughout
in
or
testicular
testicular
PGF2a
cantly
testicular
in
and
sulted
that
jig
mechanisms
the
of
capsular
these
testicular
physiological
response
contrac-
it is likely
0.14
contraction
under
et al., 1976).
from
animals
epinephrine,
for
testes
to
times
all.,
tescom-
rabbit
shown
et
for
in-
found
been
100
as
of
from
testicular
rations
ACH,
and
the
the
in
under
g of
re-
were
extracted
been
The
conditions,
to
also
ment.
responsible
intrinsic
muscle.
responded
occurred
regulation
extracted
of
contractions
capsule
vitro
in
the
tude
the
and
apparent.
per
(Hargrove
The
in
such
tion,
indomethacin
(a prostaglandin
inhibitor)
pretreatment
resulted
contrac-
between
compounds
(Gerozissis
amplitude
of
tions
(Hargrove
regu-
In this
PGF2a,
were
ter-
testicular
1973).Humoral
recently
levels
agonists
However,
of
PGE1
has
of
nerve
rat
be excluded.
and
levels
have
or
capsule,
the
in the
jig
parenchyma
response
in
extracted
0.27
jig
mo-
epinephrine
cholinergic
1973a)
capsule
regu-
It
and
been
to
cap-
that are responsible
contractions.
PG-like
a!.,
it
influ-
epididy-
capsule.
the
lar
under
the
et
PG’s
conditions.
of
have
(Seeley
auto-
testicular
produced
prostaglandin
and
the
pounds
that
capsular
to
rabbit
be important
0.038
elecin rab-
testicular
regulating
identified
mechanisms
capsular
ticular
conclude
and McLean,
however,
prostaglandin
is
the
been
locally
and
the
and
nerve
rabbit
relative
adrenergic
addition,
pos-
prepara-
to
remained
testicular
in
A
autonomic
preparations
that
in
in
or
which
no
2).
exist
at
have
trinsic
ticular
or
in
contractility
in
data
may
involved
testicular
one may
of the
involved
equivalent
of contractions
be
humoral
not
indicates
between
may
developing
in vivo
but
also possible
age
conditions
difference
preparations
of
a
contracanimals
(Table
development
vivo
The
of
frequency
postnatal
tions
ence
to
mass
capsular
from
levels
PG’s
contrac-
increased
ACH
spect,
in-
may,
an
preparations
in
increase
throughout
in
18
in in vitro
sible
of
of testicular
by preparations
generated
between
The
capsuler
Little
to
One
in no observable
change
in testicu(Hargrove
et al., 1976).
Based
capsule
(Bell
lation
cannot,
the
dur-
elements.
frequency
tions
result
in
1).
tility.
minals
occurred
(Fig.
is not
however,
age
conditions
development
the
of
increase
of testicular
large
of
in vitro
an
time
con-
weeks
capsule
of
amplitude
18
and
testicular
1976).
testicular
to
while
period
Ellis,
and
sular
be
or
capsular
contractions.
with
reserpine
did not
of the
on these
data,
nomic
regulation
isometrically,
neural,
function
contractility.
may
capsular
bits resulted
lar contractility
the
ex-
(Davis
of
increased
factors
testicular
of rabbits
testicular
by
may
of
stimulation
is supported
preparations
humoral,
capsular
these
trical
measured
animals
of
affect
Hargrove
amplitude
more
testicular
suggest
mechanisms
testicular
con-
intratesticularly
1970;
The
conditions
regulation
Pretreatment
physiological
der physiological
conditions
report
that
rabbit
testicular
contractions
adulthood
contrac-
regulate
of
data
hormonal
life
of male
rabbits.
contractions
exist
un-
under
throughout
the
testicular
capsular
hibit
vitro
existence
These
local
preparations
of age until
autorhythmic
contractions
ditions
That
1976).
testicular
from
animals
2 weeks
generated
spontaneous
SEELEY
(Figs.
2-4).
for each of
in
the
as 2 weeks
responsible
signifiagonists
for
testicular
of
age and
mediating
functional
and constant
the age groups
tested
in na(Gold-
POSTNATAL
stein
et al.,
1969).
DEVELOPMENT
In contrast,
LDR
OF
curves
erated
using PGE1 as an agonist
are not
in
preparations
throughout
the
age
tested.
for
A change
generating
ticular
capsule
sponse
of
became
of
in the
mechanisms
a response
to
is, therefore,
the
testicular
less
animals
more
inhibitory
exceeded
4 weeks.
clic
adenosine
3’,S’
cyclic
contractions
reported
AMP
in testicular
cyclic
testis,
and
aiding
testis
(Davis
et
The
and
be
in
amplitude
of
of
not
confirm
testicular
the
any
capsular
de-
the
begins,
contractions
must
other
than
greatest
occurs
be
sperm
increase
just
that
the
potential
for
contractions
is
present
throughout
development
of
rabbits;
that
the
prior
to
amplitude
of
contractions
is related
at least in part,
to the
mass of contractile
elements,
and, therefore,
increases
throughout
maturation;
that the relative
response
and
of
PGF2a
turation;
the
and
the
capsule
tion
may
that
to
be
adenylcyclase
genic
capsule
remain
enzyme
to
the
PGE1
in the
during
postnatal
of
activity
and
in
ACH,
throughout
change
indicative
activity
epinephrine,
constant
the
ma-
response
of
matura-
development
possibly
testicular
of
steroidotissues.
work
was supported
Idaho
State University
Research
Dr. John
E. Pike of the Upjohn
of prostaglandins
by a grant
Committee.
Company
used in this study.
funded
Ewing,
L. and
of the Rat Testis.
Irby,
D. (1975).
The Onto(T), DHT,
3a-DIOL
and 3(3-
Perfused
DIOL
didymides.
Rabbit
Testis-Epi-
8th Annual
Meeting
of the Soc. for the
Study of Reprod.
p. 44. (Abstr.)
Davis,
J. R. and Langford,
G. A. (1970).
Pharmacolog-
on the Testicular
Transport,
Adv.
Capsule in Relation
Med. Biol. 10,
Exptl.
Free,
j. J. and Jaffe,
R. A. (1972).
Effect
of Prostaglandins
on Blood
Flow
and Pressure
in the Testis
of the Conscious
Rat. Prostaglandins
1,483-498.
Gerozissis,
K. and Dray,
F. (1977).
Prostaglandins
in
the Isolated
Testicular
Capsule
of the Immature
and
Young
Adult
Rats.
Prostaglandins
13, 777783.
Goldstein,
A., Aronow,
L. and Kalmon,
S. M. (1969).
Principles
of Drug Action.
Harper and Row, New
p. 77-88.
J.
Hargrove,
Nerves
and
L.
Versus
Rabbit
and
Ellis,
L.
C.
Prostaglandins
Testicular
(1976).
Autonomic
in the Control
Capsular
of Rat
Contractions
in
and in vitro.
Biol. Reprod.
14, 651-657.
J. L., Seeley, R. R. and Ellis, L. C. (1973).
Contractions
of Rabbit Testes in vitro:
Permissive
Role of Prostaglandins
for the Action of Calcium
and Some
Smooth-Muscle
Stimulating
Agents.
vivo
Hargrove,
Hargrove,
3, 469-480.
J. L.,
Seeley,
R.
R. and
Rabbit
Testicular
Contractions:
tions of Prostag!andin
E1 with
Ellis,
L.
C. (1975).
Bimodal
Interacother Agonists.
Am.
J. M. and Ellis,
L. C. (1973).
Prostaglandin-like
Substances:
Initiation and Maintenance
of Rabbit
Testicular
Contractions
in vitro.
Proc. Soc. Exp. Biol. Med. 142,
205-209.
Heindel,
J. j., Robinson,
G. A. and Steinberger,
A.
(1975).
LH and FSH Stimulation
of Cyclic AMP in
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Humason,
G. L. (1972).
Animal
Tissue
Techniques
(erd Ed.), Freeman and Company,
San Francisco,
p. 3-197.
Johnson,
J. M.,
Prostaglandin
Testicular
Biol. Med.
ACKNOWLEDGMENT
This
In-
J. Reprod.
J. Physiol.
228, 810-814.
Hargrove,
J. L., Seeley, R. R., Johnson,
capsular
postnatal
the
Prostaglandins
of Testosterone
Secretion
by
Prostaglandins
in
spermatogenesis.
conclude
C.,
geny
York,
a!.,
postnatal
process
contractions
beginning
from
et
spermatogenesis
that
However,
flow
throughout
some
transport.
do
rein-
transport
from
blood
through
Langford
Since
before
argued
involved
We
capsule
functions
lymphatic
data
occur
velopment
1975).
capsule
mechanisms.
1971;
function.
contractions
the
the
a!.,
present
hypothesized
may
anabolic
Autonomic
Capsule.
Davis, J. R. and Langford,
G. A. (1970). Comparative
Responses
of the Isolated
Testicular
Capsule and
Parenchyma
to Autonomic
Drugs.
Reprod.
Fert.
26, 241-245.
cyclic
et a!.,
The
Testicular
Carpenter,
M. P., Manning,
L. and Wiseman, B. (1971).
Prostaglandin
Synthesis
in the Rat Testis. Fed.
Proc. 30, 1081.
to Sperm
49 5-5 14.
FSH)
of
testicular
enhancement
of sperm
aiding
circulation
of
the
it
the
of the testicular
Hypothesized
the
1973).
and
synthesis
(Heindel
of
AMP
function
unknown.
clude the
the testis,
the
597
J. R. (1973).
M. (1971).
Proc. 29:7.
Fed.
ical Studies
1974).
between
2 to 18 weeks
of age to
may be indicative
of the develop-
of the
The
mains
tissue,
al.,
et
Carpenter,
Chubb,
age
capsular
(LH
initiate
response
from
rabbits
29 pM PGE1
their
testicular
(Seeley
tissues
the
age
became
testicular
gonadotropins
to
Therefore,
rabbit
rabbits
the
were
as
inhibited
in
Moreover,
ment
in
AMP
and
PGE’s
may
increase
cymonophosphate
(cyclic
accumulation
and
re-
PGE1
as the
5)
(Fig.
C. and McLean,
nervation
of the Rat
Fert.
32, 25 3-258.
tes-
The
to 29 pM
stimulatory
increased
progressively
AMP)
suggested.
capsule
progressively
the
the
MOTILITY
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of Rabbit
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R. R., Hargrove,
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