Time-dependent effects of alcohol on the hypothalamic-hypophyseal-testicular function in the rat.

Adult male rats were followed throughout ethanol administration, in order to examine the time-dependent effects of ethanol on the hypothalamic-pituitary-gonadal axis. The results indicate that there is an increase in plasma prolactin levels together with a reduction in basal plasma luteinizing hormone (LH) levels, which are evident from the beginning of the intoxication period. An exaggerated response of LH to luteinizing hormone-releasing hormone was also evident from 2nd week on, in ethanol-treated rats. Basal and human chorionic gonadotropin-stimulated plasma testosterone levels were decreased in alcohol-treated as compared to control rats, at all time points studied. In addition, plasma estradiol levels were increased in ethanol-fed rats. These data suggest a direct suppressive effect of ethanol on LH release in the beginning of the intoxication period. Subsequent elevations of plasma estradiol and prolactin levels may have contributed to the maintenance of hypogonadism at the end of the intoxication period.