Impact and reversibility of chronic ethanol feeding on the reproductive axis in the peripubertal male rat

Teenage drinking continues to be a major problem in the United States as we ll as abroad. A significant depression in serum testosterone in adolescents who consume EtOH has been well described. In the male rodent model, a simi lar fall in testosterone has been reported, and prevention with the opiate blocker naltrexone has been demonstrated. To explore further the impact of chronic EtOH exposure on the reproductive axis in peripubertal rats, we des igned this study specifically to define whether or not there was recovery a fter abstinence by examining reproductive hormones and their genes during a nd after EtOH exposure. Peripubertal male rats 35 d old were fed an EtOH-co ntaining diet or a calorically matched control diet for 60 d, A third group was fed the control liquid diet ab libitum. EtOH was then withdrawn and al l animals were fed standard rat chow and water ad libitum for an additional 3 mo, The EtOH-imbibing animals were found consistently to weigh less than their pair-fed mates and liquid diet ad libitum animals. Serum testosteron e levels and testicular weights were significantly decreased by EtOH wherea s serum estradiol levels were higher, suggesting enhanced peripheral conver sion by EtOH, Spermatogenesis, assessed by histological parameters, was una ltered by EtOH, Serum luteinizing hormone levels were not different among t he groups. Hypothalamic luteinizing hormone-releasing hormone mRNA levels w ere unaffected by EtOH. During the 3-mo recovery period, all the changes re versed, with a significant increase noted in testosterone. All other parame ters remained the same among the groups. Thus, although chronic EtOH exposu re in the peripubertal age period results in significant reproductive alter ations, there is complete recovery on withdrawal.