of Pituitary-Testicular Function in Rats Is Reversed

BIOLOGY

44, 413-419

OF REPRODUCTION

(1991)

Starvation-Induced Suppression of Pituitary-Testicular Function in Rats by Pulsatile Gonadotropin-Releasing Hormone Substitution1 BERGENDAHL,2

M.

Department

A. PERHEENTUPA,

of Physiology,

Universiy

and

Is Reversed

I. HUHTANIEMI

of Turku,

20520

Turku,

Finland

ABSTRACT study

This

was

Carried

of reproductive

functions

injected

during

this

by 30%

during

the

pituitary

0.05

for

Out

time

(p

both),

but

the

of the

up-regulation

UI

by 84%

ng/kg

dose

treatment

To elucidate with

whether

a GnRH

BW

once

daily).

in accessory

No

sex

starvation

results

starvation

on

(p per

was

only

42%

(p

sting,

were

but effects

the

gonadotropins

observed

from

decreased

functions

of

the

at the

pituitary

T was

the

reduction

hypothalamic

of or

and

Inadequate

nutrient

intake

model

to identify

the

has

impairs axis been

effects

function

of the

hyan-

deficiencies

processes. Although there are some conflictmost investigators agree that the synthesis and of gonadotropins and other anterior pituitary

hormones suggested responsible

are reduced during that reduced release for the gonadotropin

examples, Bronson could To

in starved evidence

see Badger et al. [16], Bergendahl [18]). Moreover, it is also possible

the

short-term and gene

starvation expression

in starved

bility

effects

male

of direct

of pulsatile

Hormone

on gonadotropin and on testicular

rats.

Furthermore,

suppression

to

of testicular

treatment

ani(for

Received ‘These land The

and Sigrid

June studies

The

secretion, function

delineate

the

iuselius

Kiinamyllynkatu

and

by research

Pension

Insurance

contracts

from

Companies,

The Academy

during

Ui/kg

of T, or

short-term

effects

direct

of

(Rome,

Gene

(Pregnesin;

and

lU/mg

Hormone

Bucks.,

from

lunsalo, The

Foundation.

of

mone 413

U.K.)

and

common

Pituitary

for

from the gene

rat

FSH (hFSH; donated by

(Frankfurt am Main, Ac-D-pCl-Phe-D-Trp-Ser(Org.

30276),

Netherlands). (PRL) were

RIA resupplied

Program

NIADDK

antiserum Chemistry,

Nat125H]iodide Centre (Amersham [‘251]-T

Cen-

Partially by Ares-

Norway). A partially 150 lU/mg) was preparation used

CH3COOH

and

a-subunit

MD). donated

AG.

Testosterone (T) (Dept. of Clinical

Finland). cDNA probe

by The

purified human by bioassay) was

Torjesen (Aker Hospital, Oslo, preparation of hFSH (Metrodin, by Ares-Serono. The GnRH

MD). R Vihko

by bioassay)

supplied

(NIH, Bethesda, 3000 lU/mg) was

Italy). Highly 7000 lU/mg

69/104;

Probes 13500

(CR-121;

treatment

METHODS

R Canfield

Research

by the National

of Fin-

University

AND

antagonist

was donated by Organon (Oss, The agents for rat LH, FSH, and prolactin

em-

and by a grant

Dr. Maui Bergendahl, Department of Physiology, 10, 20520 Turku, Finland. FAX: 358-21-502610.

(75

levels

GnRH

Tyr-D-Arg-Leu-Arg-Pro-D-Ala-NH2

possiwe

Serono

hCG

hCG

Oulu, Oulu, Finland). The Radiochemical

supported

rats

(Ctyptocur) was donated by Hoechst F.RG.). The GnRH antagonist used,

1990.

Life

500-

treatment.

hFSH

by

and

by Dr.

Population

Dr. PA purified donated

14, 1990. were

Finnish

2Correspondence:

Turku,

3,

October

male

accompanied

serum

the

by treatment

and

model with replacements.

purified

ter for purified

(Bethesda, by Prof. Accepted

GnRH