Ethanol suppresses the postcastration rise in serum luteinizing hormone in male rats

The effects of short-term administration of ethanol on serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) concentrations were studied in castrated male rats. After 5 days of intraperitoneal administration of ethanol, serum LH concentrations were significantly lower than those of the saline-treated controls. Ethanol suppressed the progressive rise in serum LH concentrations that normally occurs after castration. Serum FSH concentrations tended to be higher after ethanol administration, but these differences were not significantly different from those of the saline-treated control animals. Ethanol has a potent and direct inhibitory effect on the hypothalamic-pituitary component of the male reproductive axis even when it is administered for a relatively short period of time.