The effects of ethanol at several points in the hypothalamic-pituitary-gonadal axis were examined in the male rat. After an acute injection of ethanol, both LH and testosterone levels declined in a parallel fashion. The percent decrease in serum LH levels was greater than the decrease in serum testosterone levels up to 60 min after the injection, but at all time intervals thereafter changes in testosterone seemed to be of the same magnitude as changes in LH. Ethanol (2.5 g/kg) also markedly depressed the increase in serum LH levels induced by castration in the male rat. The blockade of castration-induced increases in LH levels by ethanol was completely reversed by systemically administered luteinizing hormone-releasing hormone, indicating that ethanol was acting at the level of the hypothalamus rather than at the pituitary. Testicular steroidogenesis, stimulated in vivo by systemically administered human chorionic gonadotropin, was also markedly attenuated by ethanol. The inhibition of human chorionic gonadotropin-induced steroidogenesis by ethanol appeared to be noncompetitive in nature. The results of these studies suggest that ethanol exerts multiple effects on the hypothalamic-pituitary-gonadal axis in the male.
|Number of pages||6|
|Journal||Journal of Pharmacology and Experimental Therapeutics|
|State||Published - Jan 1 1979|