PMID- 1646041
OWN - NLM
STAT- MEDLINE
DCOM- 19910715
LR  - 20190510
IS  - 0006-3363 (Print)
IS  - 0006-3363 (Linking)
VI  - 44
IP  - 4
DP  - 1991 Apr
TI  - Regulation of gonadotropin secretion and number of gonadotropin-releasing hormone 
      receptors by inhibin, activin-A, and estradiol.
PG  - 725-32
AB  - Primary cultures of ovine pituitary cells were used to characterize the effects 
      of inhibin and activin on the secretion of gonadotropins and on the regulation of 
      number of GnRH receptors in the presence or absence of estradiol. Number of GnRH 
      receptors was determined by the specific binding of a saturating dose of 
      [125I]des-Gly10-D-Trp6-GnRH-ethylamide (GnRH-A). Recombinant human inhibin-A 
      (rh-inhibin-A) or inhibin in porcine and bovine follicular fluid (pFF and bFF, 
      respectively) decreased secretion of FSH in a dose-dependent manner, with maximum 
      inhibition at an inhibin concentration of approximately 0.1 nM. Neither pFF or 
      bFF affected secretion of LH, although rh-inhibin-A caused a modest decrease (p 
      less than 0.05) in secretion of LH. Treatment of cells with rh-inhibin-A, bFF, or 
      pFF approximately doubled the number of GnRH receptors. Scatchard analysis 
      indicated that increases in GnRH-A binding were due to an increase in receptor 
      number rather than a change in affinity. Additionally, rh-inhibin-A, at a dose 
      that doubled numbers of GnRH receptors, increased GnRH-induced LH release above 
      that caused by GnRH alone, indicating that the increase in receptor number leads 
      to increased responsiveness to GnRH. Recombinant human activin-A (rh-activin-A) 
      increased secretion of FSH but did not affect secretion of LH. Number of GnRH 
      receptors was not affected by lower concentrations of rh-activin-A but was 
      decreased (p less than 0.05) by 3.0 nM activin.(ABSTRACT TRUNCATED AT 250 WORDS)
FAU - Gregg, D W
AU  - Gregg DW
AD  - Department of Physiology, Colorado State University, Fort Collins 80523.
FAU - Schwall, R H
AU  - Schwall RH
FAU - Nett, T M
AU  - Nett TM
LA  - eng
GR  - HD 07841/HD/NICHD NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Biol Reprod
JT  - Biology of reproduction
JID - 0207224
RN  - 0 (Receptors, LHRH)
RN  - 104625-48-1 (Activins)
RN  - 4TI98Z838E (Estradiol)
RN  - 57285-09-3 (Inhibins)
RN  - 9002-67-9 (Luteinizing Hormone)
RN  - 9002-68-0 (Follicle Stimulating Hormone)
SB  - IM
MH  - Activins
MH  - Animals
MH  - Cells, Cultured
MH  - Estradiol/pharmacology
MH  - Follicle Stimulating Hormone/*metabolism
MH  - Inhibins/pharmacology
MH  - Luteinizing Hormone/*metabolism
MH  - Pituitary Gland, Anterior/drug effects/metabolism
MH  - Receptors, LHRH/drug effects/*metabolism
EDAT- 1991/04/01 00:00
MHDA- 1991/04/01 00:01
CRDT- 1991/04/01 00:00
PHST- 1991/04/01 00:00 [pubmed]
PHST- 1991/04/01 00:01 [medline]
PHST- 1991/04/01 00:00 [entrez]
AID - 10.1095/biolreprod44.4.725 [doi]
PST - ppublish
SO  - Biol Reprod. 1991 Apr;44(4):725-32. doi: 10.1095/biolreprod44.4.725.