Delayed pubertal development of the male reproductive tract associated with chronic ethanol ingestion

Little is known concerning the sensitivity of the reproductive tract to ethanol as a function of development. The present study was conducted to evaluate the action of chronic ethanol ingestion on sexual maturation of the male. Mice were given free access to liquid diets containing 5% (v/v) ethanol for either 29 or 43 days, starting at age 20 days. Controls were given liquid diets in which isocaloric sucrose replaced the ethanol. Daily diet consumption and peak blood ethanol levels were highest during the first 2 weeks of treatment, dropping thereafter to adult levels of approximately 680 ml/kg body weight and 160 mg/dl respectively. Plasma testosterone levels were depressed by ethanol throughout treatment, the reduction being somewhat greater when measured during week 6 of treatment (average = 74% inhibition) as compared to either week 2 (36%) or week 4 (25%). Average weights of testes, epididymides and seminal vesicles were depressed by 24% (P less than 0.002), 16% (P less than 0.005) and 13% (NS), respectively, after 29 days. Testicular development was also impaired in ethanol-treated animals after 29 days. Tunica albuginea thickness and seminiferous tubule diameter were decreased (by 31%, P less than 0.05; and 16%, P less than 0.01 respectively), whereas desquamation of immature germ cells and inactive tubules were increased (325 and 780% respectively; P less than 0.01). Quality of spermatogenesis was poorer in ethanol-treated animals (P less than 0.05). Also observed were decreased sperm motility (62% inhibition, P less than 0.01) and capacity to fertilize (decreased by 67%, P less than 0.01), and an increase in the incidence of morphologically abnormal spermatozoa (by 163%, P less than 0.001). Semen volume was lower (reduced by 57%, P = 0.05), as was the total number of motile ejaculated spermatozoa (reduced by 81%, P less than 0.05). After 43 days treatment, improvement was noted in all indices of fertility except for the number of motile ejaculated spermatozoa. Significant differences persisted only for dysmorphic spermatozoa and volume and sperm count of electroejaculated semen. These data suggest that ethanol ingestion during pubertal development can delay several aspects of sexual maturation in the male.