title: Alterations of 20 alpha-hydroxysteroid dehydrogenase activity in cultured rat granulosa cells by follicle-stimulating hormone and testosterone.
abstract: The effect of follicle-stimulating hormone (FSH) and testosterone (T) on rat granulosa cell progestin metabolism was investigated by incubation of the cells for 24 h with FSH and/or T and subsequent reincubation with an appropriate rabiolabeled steroid for 3 h. Exposure to varying concentrations of FSH (8-1000 ng/ml) and T (4-500 nM) decreased overall 4-[14C] progesterone utilization and accumulation of 20 alpha-reduced metabolites of progesterone in a dose-related manner. The accumulation of 5 alpha-reduced metabolites was not markedly changed by FSH and T treatments. Treatments with FSH and/or T decreased utilization of all progestins studied: progesterone by 30-50%, 20 alpha-hydroxy-4-pregnen-3-one by 23-31%, 3 alpha-hydroxy-5 alpha-pregnan-20-one by 41-64%, and 5 alpha-pregnane-3 alpha,20 alpha-diol by 26-34%. The greatest effects were observed following FSH + T treatments. Decreased utilization of substrates was associated with the decrease of 20 alpha-hydroxy-steroid dehydrogenase activity; the conversion of progesterone to 20 alpha-hydroxy-4-pregnen-3-one was decreased by 44-62%, the conversion of 20 alpha-hydroxy-4-pregnen-3-one to progesterone was decreased by 41-61%, the conversion of 3 alpha-hydroxy-5 alpha-pregnan-20-one to 5 alpha-pregnane-3 alpha,20 alpha-diol was decreased by 42-69%, and the conversion of 5 alpha-pregnane-3 alpha,20 alpha-diol to 3 alpha-hydroxy-5 alpha-pregnan-20-one was decreased by 53-60%. The incubation of granulosa cells with cyanoketone (10(-6)M), an inhibitor of delta 5,3 beta-hydroxysteroid dehydrogenase, virtually eliminated de novo progesterone production but did not alter the inhibitory effect of FSH and T on radiolabeled progesterone utilization and accumulation of 20 alpha-reduced metabolites, indicating that the observed effects are not influenced by endogenous production of progesterone. It was concluded from these studies that both FSH and testosterone inhibit the 20 alpha-hydroxysteroid dehydrogenase activity and consequently decrease progesterone catabolism by granulosa cells.
mesh_terms: D015089:20-Hydroxysteroid Dehydrogenases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004092:20-alpha-Dihydroprogesterone / Q000378:metabolism; D043607:20-alpha-Hydroxysteroid Dehydrogenase; D000818:Animals; D002478:Cells, Cultured; D003489:Cyanoketone / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000378:metabolism; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D006107:Granulosa Cells / Q000201:enzymology*; D011276:Pregnanediol / Q000378:metabolism; D011280:Pregnanolone / Q000378:metabolism; D011284:Pregnenolone / Q000378:metabolism; D011374:Progesterone / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013237:Stereoisomerism; D013739:Testosterone / Q000494:pharmacology*
chemical_list: D004092:20-alpha-Dihydroprogesterone; D013739:Testosterone; D003489:Cyanoketone; D011374:Progesterone; D004958:Estradiol; D011284:Pregnenolone; D005640:Follicle Stimulating Hormone; D011280:Pregnanolone; D015089:20-Hydroxysteroid Dehydrogenases; D043607:20-alpha-Hydroxysteroid Dehydrogenase; D011276:Pregnanediol