Possible role of prolactin in the induction of hypogonadism by chronic alcohol treatment in the male rat.

Treatment of adult male rats with ethanol for a period of six weeks resulted in a numerical but not significant increase in plasma prolactin levels together with a reduction in plasma luteinizing hormone (LH) levels. Although basal plasma testosterone (T) levels were not affected in ethanol-treated animals, testicular weight was reduced and seminiferous tubules exhibited signs of atrophy. The responses of LH to luteinizing hormone releasing hormone (LHRH) and T to hCG were significantly impaired in ethanol-treated rats (p less than 0.01). Treatment with bromocriptine (1 mg/kg body weight/day), resulted in the expected decrease in plasma levels of prolactin and an increase in basal plasma LH levels to the levels found in control groups. Basal plasma T levels were not affected by bromocriptine. However, both plasma LH responses to LHRH and plasma T responses to hCG were significantly improved by bromocriptine treatment in alcoholic rats and became similar to the responses measured in control animals. The results suggest that bromocriptine-induced suppression of prolactin release has a beneficial effect on ethanol-induced hypogonadism.