The Effect of Injected Ovarian Steroids on Ovarian and Pituitary ...

BIOLOGY

OF

2,

REPRODUCTION

The

63-70

Effect

(1970)

of

Inlected

and

Ovarian

Pituitary

Function

J. N. SHELTON1 Gene

fics

Laboratory,

University

of

Three

experiments,

using

steroids

15 of

the

Ten

on

estrous

cycle

milligrams

fern

score

fern

One of Fifty

of

increased

(50

two

steroids

ovarian

two

Christian daily will inhibit

progestogens

for

500 20.

The

data

mg

of

had

no

of

weight

the

indicate

inhibit

termination extensive

mode

of action

tian,

total

and

Casida

of

of these

(1951)

of

effect

on

(250

.sg

stimulating

1

On

(LH) leave University

in from

of

14

or

increased

of

40

progesterone

the

mg

of

but

did not

20-

(FSH) intact

Sydney,

or

and

of

progesterone. follicle

of

the

largest

mg

of

and

progesterone

but

addition

to fluid

lease

of

observations

is

terone inhibit the

the

weight

of

whereas

(1966)

the

LH.

This that

reported

acetate

ovulation had and inhibited

conclusion

blocked

of

with proges-

at doses does not

follicles 1966).

on pitucyclic re-

agrees

administration

of ovarian

that

which

no effect only the

and other progestogens estrus and ovulation

growth

which inhibit

(Ulberg

et

al.,

1951;

Zimbelman,

estrus results

in cattle with progestogens commonly in poor fertility (Trimberger and

Hansel, to the

1955). failure

inhibit

adequately

function

in the

It

appears

Synchronization

It is possible of progestogen

that

pituitary

of

this is due treatment to and

ovarian

cow. probable

secreted simultaneously Little is known of the 63

the

melengesterol

hydroxyprogesterone Hus-

of

effects,

FSH

Zimbelman

in

Australia.

volume

these and

of

pituitary

the

LH.

of

luteinizing

or

decreased

synthesis

and FSH

pro-

morphology

follicular

itary

of follicle-

Animal

of

estrus

ovariectomized

Sydney,

In

of

complex, from acting

levels

diameter

20 mg

100

day)

doses

Chris-

that

score,

with

ovarian

inhibits

and

and Cole (1957) Meyer, and Casida of a single injection

Department of

cycle

arborization

per

heifers.

compounds

postulated

pituitary

hormone

hormone

bandry,

on

of

with

lutea.

weight

FSH

estrus

Ulberg,

the gonadotropic hormone (LH),

upon the ovary. Nellor and Labhsetwar, Tyler, (1964) found no effect

of progesterone

estrous

diameter given

estradiol

of treatment. investigation

established.

gesterone inhibits mainly luteinizing

effect Day

progesterone.

corpora

that

release

synchronization

unequivocally

the

from

Addition

compared

the when

cattle.

not

the 19.

depressed follicles

Estradiol

decreased

The

22-25

day)

the

progesterone

Casida (1948) reported of 50 mg of progesterone and ovulation in cows until

6 days after has led to

5

of

and activity

palpable

Days

Day

and

together

and injection estrus

that

to This

steroids

per at

together

stroma.

study

daily

1).

15

18

decreased

at with

mg

follicle

of of

estradiol-173 follicles

activity

largest

Day

to

injected

Day

Days

Wisconsin

conducted

when

estrus-inhibiting

number

characters

Progesterone

on

the

were

(estrus from

mucus

milligrams

and of

gonadotropin the

500

palpable these

heifers,

25

Madison,

1969

function

daily

cervical

follicle,

micrograms

number

40

Heifer

CASIDA

Wisconsin,

18,

Ovarian

scores.

and

largest

and

19 or

increased pattern

hundred

the

Day

L. E.

June

pituitary

progesterone of

hydroxyprogesterone reduce

32,

and

to

of

pattern

15,

ovarian

on

in the

AND

Received

ovarian

Steroids

that and role

in

the

estradiol-l

cow

203are

with progesterone. of these steroids

64

SHELTON

in

the

regulation

function This

of

in this paper

designed

to

terone,

pituitary

and

diol-173

three

investigate

on

the

ovarian

effects

in

2 X

estrogen

of

progesestra-

(0

menced

all

pituitary

on

MATERIALS

Experiment weighing

1.

three

equal

mg

progesterone day,

The

the

Day

15 to

the

except

to of by

means

of

Each and

mucus

tion

score and

(1 to Ulberg

Data

were

the

a measure

and

number

of

transformed

to

Experiment heifers

dose day)

and

dose

recorded

Prior

to

into

two

21;

Stage

stage

2 was

the 4

days.

only

groups

were

included

the Day

18, and

21,

in

from the were

made

Forty

Holstein

prior

necessitated

estrous

on

pituitary from each

Day

and

gland, heifer

to the laboratory. were

stored

dissected

from

-1SC

at

to await

content. each

ovary

were

the

largest

in

fluid,

determine

and

the

weight

of

follicle,

weight

total

of

weight

the of

the total

corpus follicular

stroma

of

blotting

was

dry

weight

was

assayed

homogenized by

1961). (0.075,

and

recorded.

was

ovarian

lyophilized,

The

pituitary

ascorbic

acid

LH deple-

Two rats were used for 0.225, 0.675 mg) from

capsules

into

30-day-old

(Bhalla,

rat

received

six subcutaneous

at

12-hour

intervals

HCG

as

the

transported

fluid

of

Memon,

powder

1.

topsied

36

in

ovary

weights

hours

Holtzman

Woody,

after

and

each each

the

female

Casida,

1969).

injections

commencing

implantation.

The

assay

last

injection

of 4 IU

at

rats of

the

time

were

au-

HCG

and

recorded.

divided 19, 20, and For

each

the

data

animals

in to

of between

the

(10

mg

1.

per

The

day)

effects

and

Stage treat-

2.

lengths

of

(40

the

Table

1. This

estrus

in

progesterone

only

estrous dose one and

of progesterone

progesterone

hydroxyprogesterone six

weighing

RESULTS Experiment

exhibit

remaining

heifers

This

removed

rats

per

stage. 3.

estrous

FSH activity was assayed by HCG-synergism in rats (Steelman and Pohley, 1953). This was a twopoint assay using doses of 35 and 70 mg of pituitary powder. When the amount of powder permitted, two rats were treated with each dose of each gland. The powder was implanted subcutaneously in No. 5

sg Expt.

of

analysis

(controls)

not

was

Animals

was

began the

of

gland

activity

Each

made,

25.

means

progesterone

data

comparisons

Experiment

were after

zero

23,

estrogen

glands

for

ovarian

the

mg

50 in

25,

no were

and

19,

20.

was weighed after multiple the tissue, and this weight plus the weight of the corpus luteum was subtracted from the gross weight of the ovary. On the completion of slaughtering each anterior

500

transformed

24,

Shortly

and

Day

Days

Thus,

within

were 18 to

of com-

Day

Day

slaughter

were

follicular

and

gelatin

studied

and

those

1 was

estrus,

ments

to

22,

receiving

randomly

factors

(0

Days

groups

Holstein

100,

Stage analyzed

data

Orthogonal

data Day

heifer

observations

similar

the

interval,

stages.

20,

treatment,

were

analysis

1. The

(0,

of

dose

gland. of

per

allotted

The

on

on

of slaughter. animal that

gonadotropin

tion (Parlow, of three doses

to give

nulliparous

of estradiol-1713

of

a

after

cubed

the

and

to logarithms.

lb. were

dose

and

Treatment

time

weighed,

To

pituitary

a slide,

diameters

follicles

4 >( 2 design,

duration

data

for

Thirty-two of

inseminaon

1.

of progesterone

The

Expt.

+

a

each

variance

transformed palpable

‘/x

treatdays

Patterson,

were

if they

recorded

slicing

using

of

heifer

600-800

experiment

day). and

2.

weighing

were per

in each

of

Alliston,

analysis

and

only

pituitary

of

fluid

daily,

an

Estimated

volume,

were

an

of

progesterone

experiment

were

day)

terminated

on ice until

volume

weight

arborization

that

to

of

on

to

to

the

Data

to spread

and

slaughtered

after

ovary, luteum.

from

was

for

1)

the

same

fitted

14

uterus

for

Data

indicative

aspirated

sample

day).

tissue,

ob-

start

the

per

anterior

were as

the

.sg

of one

stored

using

conducted

On

250

designated

bioassay corn

Day

=

heifers

from was

evaluated

follicle

of estrus

behavior

transformations.

largest

in

heifers

and

and

other

a control.

a syringe

subjected

appropriate

The

as

estrus.

6) similar (1958).

and

10

was

mucus

tube. air-dried,

heifer

10

The

17,

of

cervical

with with

other

and

16 onset

treated

estrous

per

no

ovaries,

treated

subcutaneously

palpation

Days the

sample

estrus.

mg

Immediately

to

was

(day

of

for

heifers

random

was served

25

standing

at

20-hydroxyprogesterone

group

for

Ovarian for

ment

mg

Day

daily

of

estrus.

one

injected

onset

twice

criterion

40

third were

until

group

50

an

considered

19.

Holstein

assigned

day,

and

and

served of

One per

steroids

oil from

were

and

reassignment

METHODS

nulliparous

lb.

groups,

progesterone

or

Fifteen

600-800

mg per

AND

(0

slaughtered

to the

to

factors

were

receiving

randomly

The

Day

heifers

were

heifers.

allotted

2 design.

progesterone

and and

lb. were

650-800

experiments

response

levels

ovarian

CASIDA

of

species. describes

203-hydroxyprogesterone,

gonadotropin

AND

mg

cycles

of of

plus day)

on

are

shown

in

progesterone five

20-

per

heifers

203-hydroxyprogesterone

inhibited whereas

OVARIAN

TABLE THE

EFFECT

OF

mg

PLUS

day)

per

I (10

PROGESTERONE

PROGESTERONE

STEROIDS

mg

per

day)

AND

(40

2013-HYDROXYPROGESTERONE

ON

ESTROUS

CYCLES

IN

IN

istered

of heifers Mean

and

length

Treated

inhibited

Progesterone

5

Progesterone

1

that

of

5

23.5

4

significantly greater and progesterone-treated

in control

(p

estrus

resulted

in

heifers

receiving

the

many

Day

analyzed of the

21,

on in

jected

heifers

fern

Days

the

largest

five

heifers

( .025) groups.

gesterone.

heifers.

cycle

were to

pattern

score. 19 were

heifers

the

(Table

follicle

nor

on the

number

2.

In

statistical

Expt.

the

size

of

the

of follicles. analysis

orthogonal

2

There

2).

on

mg

given

100

and

this

stage,

mg

of progesterone

mean

diameter

follicles

(p