Control of follicle-stimulating hormone secretion by steroid-free bovine follicular fluid in the ovariectomized rat.
The effects of steroid-free bovine follicular fluid (bFF) and sodium phenobarbitone on spontaneous LH releasing hormone (LHRH)-induced secretion of FSH and LH were studied in ovariectomized rats. Luteinizing hormone releasing hormone was administered by infusion to rats anaesthetized with phenobarbitone. Bovine follicular fluid reduced FSH release and synthesis. Luteinizing hormone release remained unaffected after bFF treatment. Phenobarbitone reduced both FSH and LH release. The observed suppressive effects of bFF and phenobarbitone on FSH secretion were additive, suggesting that the basal release of FSH has an LHRH-dependent and an LHRH-independent component. Furthermore, bFF did not affect pituitary responsiveness of LH secretion to LHRH and reduced the responsiveness of FSH secretion only when administered some time before the LHRH challenge. The present observations support the view that in the ovariectomized rat the pituitary gland is the only site of action of inhibin-like activity as present in bFF.
D000818:Animals; D001826:Body Fluids / Q000378:metabolism; D002369:Castration; D002417:Cattle; D003864:Depression, Chemical; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood / Q000378:metabolism*; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects / Q000378:metabolism*; D007986:Luteinizing Hormone / Q000097:blood; D006080:Ovarian Follicle / Q000378:metabolism*; D010634:Phenobarbital / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D010634:Phenobarbital