The effect of hypophysectomy on inhibin production by adult rat ovaries: changes in ovarian inhibin gene expression and serum inhibin.
We have investigated the effect of hypophysectomy on adult rat ovarian inhibin alpha- and beta A-subunit mRNA, serum inhibin, and circulating gonadotrophin levels. Immediate declines in ovarian inhibin gene expression and serum inhibin were observed following hypophysectomy, with a nadir on day 4. However, inhibin synthesis determined by these parameters was still apparent at 16 days post-hypophysectomy. Gonadotropin levels were suppressed following hypophysectomy and the fall in inhibin production was highly correlated with disappearance of FSH from the circulation. This study demonstrates that removal of pituitary gonadotropin stimulation results in diminished ovarian inhibin synthesis and provides further evidence indicating that FSH stimulates granulosa cell inhibin synthesis by enhancing inhibin gene transcription.
Davis
S R
SR
Monash Medical Centre, Melbourne, Australia.
Carson
R S
RS
Krozowski
Z
Z
Burger
H G
HG
D000818:Animals; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D005796:Genes; D007016:Hypophysectomy; D007265:Inhibins / Q000096:biosynthesis / Q000097:blood / Q000235:genetics*; D007700:Kinetics; D007986:Luteinizing Hormone / Q000097:blood; D046911:Macromolecular Substances; D010053:Ovary / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics* / Q000302:isolation & purification; D051381:Rats; D012016:Reference Values; D014158:Transcription, Genetic
D046911:Macromolecular Substances; D012333:RNA, Messenger; D007265:Inhibins; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone