title: Interaction between purified ovine inhibin and steroids on the release of gonadotropins from cultured rat pituitary cells.
abstract: Primary pituitary cell cultures derived from adult male rats were used to explore the interaction between purified 32K ovine inhibin and gonadal steroids on the modulation of basal and GnRH-stimulated secretion of FSH and LH. Purified o-inhibin was a potent inhibitor of basal FSH secretion (IC50 = 3.4 pM) and 10 nM GnRH-stimulated FSH and LH secretion (IC50 = 8.8 and 18.4 pM, respectively). Purified o-inhibin had no effect on basal LH secretion. In this system, the androgens testosterone, 5 alpha-dihydrotestosterone, and androstenedione slightly stimulated basal FSH secretion, and o-inhibin could reverse this stimulatory effect. By contrast, androgens suppress GnRH-stimulated FSH and LH secretion. In combination, androgens and o-inhibin provided greater inhibition of GnRH-mediated gonadotropin secretion than either did alone.
mesh_terms: D000728:Androgens / Q000494:pharmacology*; D000735:Androstenedione / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D013196:Dihydrotestosterone / Q000494:pharmacology; D004958:Estradiol / Q000494:pharmacology; D005640:Follicle Stimulating Hormone / Q000378:metabolism*; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D007265:Inhibins / Q000494:pharmacology*; D007700:Kinetics; D007986:Luteinizing Hormone / Q000378:metabolism*; D008297:Male; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012756:Sheep; D013739:Testosterone / Q000494:pharmacology
chemical_list: D000728:Androgens; D013196:Dihydrotestosterone; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D000735:Androstenedione; D004958:Estradiol; D007265:Inhibins; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone