title: Differential inhibition of progesterone synthesis in bovine luteal cells by estrogens and androgens.
abstract: We investigated the roles of estrogens and androgens in the progesterone biosynthesis of bovine luteal cells. The responsiveness of primary luteal cells to the stimulation of tropic agents was observed in a dose-dependent manner. Estrogens and androgens significantly inhibited tropic agent-induced progesterone secretions, but glucocorticoids did not, which indicated the inhibitions were specific. The failure of exogenous 8-Br-cAMP to prevent these inhibitions suggested that took place at the post-cAMP steps. The immunoblot showed that testosterone remarkably decreased the amount of induced P450scc protein after 6-hour treatment, yet 17beta-estradiol did not. The 3beta-HSD activity assays demonstrated that both 17beta-estradiol and testosterone efficiently blocked induced 3beta-HSD activities. Both inhibitory effects of E2 and T on progesterone synthesis were observed one hour after treatment and accompanied with suppressed 3beta-HSD activities. This study presents that estrogens and androgens specifically inhibit bovine luteal function through different mechanisms.
authors: Department of Veterinary Medicine, National Taiwan University, Taipei, Republic of China.
authors: I C
authors: IC
authors: Guo
authors: L S
authors: LS
authors: Wu
authors: J H
authors: JH
authors: Lin
authors: B C
authors: BC
authors: Chung
mesh_terms: D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D002417:Cattle; D002478:Cells, Cultured / Q000378:metabolism; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000037:antagonists & inhibitors / Q000378:metabolism; D003338:Corpus Luteum / Q000187:drug effects* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D006913:Hydroxysteroid Dehydrogenases / Q000037:antagonists & inhibitors / Q000378:metabolism; D015151:Immunoblotting; D011374:Progesterone / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D013739:Testosterone / Q000494:pharmacology*
chemical_list: D004791:Enzyme Inhibitors; D015124:8-Bromo Cyclic Adenosine Monophosphate; D013739:Testosterone; D011374:Progesterone; D004958:Estradiol; D006913:Hydroxysteroid Dehydrogenases; D002786:Cholesterol Side-Chain Cleavage Enzyme