BIOLOGY

OF REPRODUCTION

Oviductal

18, 409-417

(1978)

Motility Amplitude and Ovarian Steroid During Egg Transport in the Rabbit

C. H. SPILMAN’,

A.

Worcester

A.

SHAIKH2

Foundation

for

Shrewsbury,

and

J.

M.

K.

Experimental

Massachusetts

Secretion

HARPER3

Biology, 01545

ABSTRACT New Zealand White rabbits were used to measure oviductal mortiity amplitude in vivo and ovarian vein concentrations of estrone (E,), estradiol (E2), progesterone (P) and 20o-hydroxypregn4-en-3-one (20o-OH-P) at several times before and after the induction of ovulation with human chorionic gonadotropin (hCG). The experiments were designed to determine the relationship between oviductal motility amplitude and ovarian steroid secretion during the time eggs are being transported through the oviducts. Oviductal motility amplitude of the isthmus decreased slightly at 6 h after hCG, then steadily increased to a peak at 36 h and subsequently declined between 36 and 72 h after hCG. E2, P and 20a-OH-P increased to peak concentrations at 6 h after hCG. At 12 h after hCG E, and E2 were at the lowest levels observed in these experiments. E, increased between 12 and 36 h and then declined slowly up to 72 h after hCG. From its nadir at 12 h, E2 increased gradually until 72 h. Both P and 20o-OH-P decreased after their peaks at 6 h. P increased again at 36 h after hCG, but 20o-OH-P remained low from 36 to 72

h. There of

the

were no statistically ovarian

amplitude

through motility

significant

correlations

between

oviductal

motility

the oviduct. The postovulatory increase in progesterone secretion may decrease amplitude thereby allowing the eggs to move through the isthmus into the uterus.

rabbits

was

oviduct

was

not

correlated;

very

oviduct was relatively that these differences differences in ovarian

changed

little

but

increased

during

the

sharply

lar

differences

first

4 h after

hCG,

oviducts

until

10 h after

hCG.

(Coutinho

in in

1970). Hilliard and coworkers 1963, 1964; Hilliard and

activity

2

and

These

investigators

activity

in

left

Accepted

Received ‘Present Company,

in

the

nonovubated

also and

September

20,

Kalamazoo,

Address: and Education,

Texas

78284.

Science Center, Texas 78284.

Address: 7703

next

reported

right

days

One

muscular of

1977.

Research,

Michigan

The Upjohn

49001.

Southwest Foundation for ReP.O. Box 28147, San Antonio, University Floyd Curl

of Drive,

Texas San

(Hilbiard Sawyer,

publication

(Hilliard

Health Antonio,

earlier

Blanco

et al.,

et al., 1961, 1964; Hilliard

Eaton,

1971)

ovarian steroid secrein the rabbit from the implantation. In this experimental observathe interval between

mating (Harper, mating.

and expected ovulation at 9.5-13 h 1961a), or between 4 and 6 days after Observations were made in only 3

animals

(1

mating)

during

sage Harper 409

one

extensive studies rates in rabbits.

and

dealt specifically with the tion changes which occur time of mating through latter study, most of the tions were made during

estrous

reported

Sica

Eaton, 1971) have made of the ovarian steroid secretion

to

rabbits.

that

oviducts

July 1,1977. Address: Fertility

search

2

during

estrous

been

1969;

continued level. Folmuscular

decreased

cases

contrabateral

They suggested be due to local secretion. Simibetween right and left

Between 10 and 24 h isthmic activity to increase gradually to its highest lowing the peak at 24 h, isthmic recorded

the

inactive. might hormone had

Maia,

oviductal

many

while

activity

women

and

in

active

Sabomy and Harper (1971) recorded muscular activity of the oviductal isthmus in rabbits at several times after an ovulation-inducing injection of human chorionic gonadotropin (hCG). The mean amplitude of contractions

bevels

and any

steroid may

INTRODUCTION

then

amplitude

concentrations. Thus, changes in ovarian steroid secretion and changes motility be out of phase; preovulatooy steroid surges may induce delayed changes motility. It is suggested that preovulatory steroid surges induce an increase in the of contractions of the oviductal isthmus which effectively impedes passage of eggs

in oviductal in oviductal

vein

of

at

eggs (1972)

23

h, 1 at 48 h and 1 at 72 h after the time corresponding to pas-

through measured

the

oviducts. several

Shaikh

steroids

and

in right

SPILMAN

410

and

left

ovarian

concurrently

veins and

significant

differences

tion

between

rates

rabbit.

This

by

existed

et

ab.

rates

ovaries,

do

but

exist

that

left

Shaikh

by

(1974)

ovarian

and and

oviductal secretion

left

in

and

right not

the

motility during

by with

(1972) and

the

mean

time

eggs

in

point

had

time

transport.

AND

and ovarian during the

METHODS

Briefly, the recording method involves chronic placement of pressure-sensitive silicone micro-balloons in the lumen of the proximal isthmus. Pressure changes within the oviductal lumen were recorded on a Grass

ty

was

Statham

recorded

P-23 20-60

for

AC

transducers.

from

mm

Motili-

4

ovulation

Oviductal

tion

stigmata motility

was recorded

on Grass polygraph

digital information information was

and no older

on

analyzed

as analog

rectilinear

chart

magnetic

tape.

by

corpora

computer

lutea. informa-

paper and as The

digital

program

recording period Each mean value on from 40-100 amplitudes shown left oviduct means

a 10 mm contractions. The oviductal motility in Fig. 1 are an average of right and for each discussion

rabbit of

within groups. the results, the is used as the

In the

and of oviductal of oviductal

presentation

amplitude measure

extraction

of plasma,

as

celite

column

chro-

matography of the extracts and radioimmunoassay of estrone (E,), estradiol (E2) and progesterone (P) were performed as reported by Shaikh and Harper (1972). The 20o-hydroxypregn-4-en-3-one (2Ocx-OH-P) was eluted from the celite columns with 5 ml iso-octane.

This fraction was oxidized to progesterone, subjected to celite column chromatography again and the progesterone fraction collected and assayed as usual. The experimental observations were subjected to the statistical tests indicated in the Results section. RESULTS

Motility

The mean amplitudes of contraction of the left and right proximal isthmi during egg transport are shown in Table 1. There were no

periods

right

significant oviducts

when

left

compared

cant

using

and

Wilcoxon’s hypothesis oviductal

right

the

amplitudes

data

were by

but

active

size

pooled

of the

the

rabbits.

differences of the

time or

by

was

(a was

Thus,

differences

oviducts

in rabbits

do

shortly

differences

were

the

the

abso-

left

evaluated

0.01) detected

estrous rabbits, 2 of 4 rabbits 12h, 1 of7at36h,Oof4at48hand0of7at between

oviducts

Hence,

and using

variation for motility meaerror term. A statistically

significant difference ducts within animals

after

t-test

between

amplitudes

the coefficient surements as

these

across

a paired

whether

within

oviduct

h.

were

t-test, nor were signifileft and right oviducts

analyzed

rabbits,

equally

72

between the the 6 time

of

signed rank test However, the of interest is not whether left activity equals right oviductal activity

between

right

and

between

when

periods

differences at any

a paired

differences

detected

lute

estrous

animals, from 4 animals 6 h after an i.v. injection of 100 L.U. hCG, from 3 animals 12 h after hCG, from 7 animals 36 h after hCG, from 4 animals 48 h after hCG and from 7 animals 72 h after hCG. Immediately after the oviductal motility was recorded, the animals were anesthetized with sodium pentobarbital and right and left ovarian veins were cannulated as reported by Shaikh and Harper (1972). Blood plasma was collected and stored at -20#{176}C for subsequent steroid analysis. After blood was collected, it was confirmed that the ovaries in estrous animals and in animals at 6 h after hCG did not contain corpora lutea and that the ovaries in animals at other experimental times contained

recent

for the entire each oviduct. was based

for interval

for

statistically left and

mature, female New Zealand White rabbits which had been individually caged for at least 3 weeks were used. The animals had a standard rabbit diet and water available ad fib. Muscular activity of the isthmus was recorded in vivo from both right and left oviducts exactly as reported previously (Spilman and Harper, 1973).

using

calculated

Oviductal

Twenty-nine

polygraph

contractions

then

it was second

attempted

oviductal motility in the same animals

MATERIALS

felt the

previously

to measure both steroid secretion egg

et al. mean

ovarian steroid are being trans-

oviducts. We to investigate

no one

reported

Hilliard

ported through the particularly important because

to left and

between

of

was

Steroid

Sabomy

and

relationship

(Spilman and Sutter, 1976). An of oviductal contractions was calcuintervals during the 20-60 mm One average value for the ampli-

motility.

differences

secretion

tude

contractions

investigators

were designed in right and

steroid

Harper

2)

of tubal

of

are

latter

motility reported (1971) are correlated

and

results

differences The

same

criticized

differences

between

The present experiments determine: 1) if the differences

right

secre-

the

whose

earlier amplitude lated for 10 mm recording sessions. average

ovaries within rabbits respond to circulating gonadotropins.

synchronously

oviductal Harper

of

that

these

significant.

concluded

steroid

sharply

(1974),

that

statistically

in

showed

described

cannulated statistically

ovaries was

experiments

secretion

were that

the

conclusion

Hilliard

similar

which

concluded

ET AL

after

oviductal

in

estrous

hCG

tend

at 6 h, 2 of

in exist

between ovifor 3 of 4

motility rabbits

administration,

to

3 at

disappear

and

but by

36

was

sepa-

ovarian

vein

hCG. Oviductal

rated steroid

on

motility

the levels

within

basis

of

for

each

high

animals

and

of the

low

4 steroids

assayed.

h

OVIDUCTAL

MOTILITY

AND

OVARIAN

STEROIDS

Oviductal

motility

ipsilaterab or bower

+4 -41 N

time

coxon’s

period lower

‘

for E1,

on

ovarian veins concentrations

periods

signed

in Table 2. ences among o.

amplitudes

to the steroid

within

*

411

and

rank

test.

the

sides

having the higher were grouped

analyzed

These

using

data

Wil-

are shown

There were no significant differthe mean amplitudes at any time

any hormone. P and 20a-OH-P

to somewhat

higher

In estrous animals the levels corresponded

amplitudes

whereas

estradi-

ob showed the opposite trend. At 36 h, when mean oviductal activity was at its peak, the high estrogen concentrations were associated with higher oviductal amplitude while the high progestin er

concentrations oviductal

existed, not

-H

their temporal

right

a -

N

.-

‘r

change

for

There

6 h after N

with

low-

these

significance,

trends

if

any,

is

,

of the

50

36 and

48

gradual

decline

This

isthmus

proximal

transport are

is shown

means

animals

all

is a slight

hCG.

steady increase 36 h. An abrupt

in

tubal egg presented

oviducts

interval.

‘5

biological

activity during Fig. 1. The data

‘.#{176}

associated

Although

clear. The

N

-

were

activity.

at

decrease

decrease

of

in

left

each

and

time

in activity

is followed

at by

a

in isthmic activity to a peak at decline in the muscular activity

proximal

isthmus

h after up

was

observed

between

hCG. to

There was then a more 72 h. The bevel of activity

at 72 h after hCG, when eggs are moving the uterus, was 27% of that at estrous and 17% of the peak value at 36 h.

into only

.

1*

0

6

12

36

72

46

HOURS AFTER hCG

5

FIG.

,..

isthmus ‘5

Z

1.

in

Mean

New

motility

Zealand

during

injection

Vertical

bars represent

of

amplitude

rabbits

after

human chorionic standard errors

of

the

oviductal

an ovulation-ingonadotropin.

of the mean.

412

SPILMAN

ET AL

v --

,

‘

--

--

--

.e

11+4

-41+4

+411

N N

N

1111

“ N

N

N

N

N

N

N

0

.9

9

‘5

V

-u

#{176}-

U

C) ‘5

2

I-’

8

L1

fi N

‘5

OVIDUCTAL

Ovarian

Steroid

Secretion

The

ovarian

vein

tions using ence

12 h after The secretion

steroid

animals

decreased

of

steroids

was for

dictive oviduct

between

20a-OH-P

at

each

time

period.

12 h after

50%

hCG

of

36 h estrone rose to the highest measured in these experiments

declined gradually up Ovarian vein estradiob hCG, a peak concentration

concentraand then

to 72 h after hCG. rose sharply following being measured at 6

h. Ovarian vein also rose to peak

then declined. between 36 and tion at declined

progesterone values at

Progesterone 48 h. After

for

and 6 h and

left

right (N=16, r=0.87,

P