Ethanol inhibits testosterone biosynthesis by direct action on Leydig cells.
Ethanol was found to suppress gonadotropin-stimulated testosterone biosynthesis in sexually mature male rats in vivo and in intact Leydig cells in vitro. A similar ethanol dose-response inhibition curve was also observed when either whole or homogenized cells were stimulated by dibutyryl cyclic AMP. In the presence of pharmacologically relevant ethanol concentrations, added NAD+ restored testosterone production to stimulated control levels. These results demonstrate a direct inhibitory effect of ethanol on testicular testosterone synthesis. The site of inhibition is primarily intracellular and the mechanism is probably through a decrease in the NAD+/NADH ratio caused by ethanol oxidation.
D000818:Animals; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D000431:Ethanol / Q000494:pharmacology*; D066298:In Vitro Techniques; D007985:Leydig Cells / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D009243:NAD / Q000494:pharmacology; D051381:Rats; D013739:Testosterone / Q000096:biosynthesis* / Q000097:blood; D013997:Time Factors
D006063:Chorionic Gonadotropin; D009243:NAD; D000431:Ethanol; D013739:Testosterone