Differential inhibition of progesterone synthesis in bovine luteal cells by estrogens and androgens.
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.
Guo
I C
IC
Department of Veterinary Medicine, National Taiwan University, Taipei, Republic of China.
Wu
L S
LS
Lin
J H
JH
Chung
B C
BC
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*
D004791:Enzyme Inhibitors; D015124:8-Bromo Cyclic Adenosine Monophosphate; D013739:Testosterone; D011374:Progesterone; D004958:Estradiol; D006913:Hydroxysteroid Dehydrogenases; D002786:Cholesterol Side-Chain Cleavage Enzyme