REVERSAL OF ETHANOL-INDUCED TESTOSTERONE SUPPRESSION IN PERIPUBERTAL MALE RATS BY OPIATE BLOCKADE

Teenage drinking is a major problem in the United States, as well as a broad. Besides psychosocial implications, ethanol (EtOH) has detriment al effects on the reproductive system. Clinical problems associated wi th reduced reproductive hormones include osteoporosis, decreased muscl e function, anemia, altered immune function, prostate involution, and decreased reproductive abilities. Education coupled with strategies ai med at preventing these deleterious consequences even in the face of c ontinued EtOH intake is extremely important. We have tested the possib ility that naltrexone, a drug currently used in patients to decrease a lcohol craving, might also prevent the fall in the male hormone, testo sterone, caused by EtOH exposure. Rats aged 35 days old (prepubertal), 45 days old (midpubertal), and 55 days old (late pubertal) were injec ted (intraperitoneally) with either saline, EtOH, naltrexone, or EtOH plus naltrexone. In the two older age groups, EtOH significantly suppr essed testosterone, which was prevented by administration of naltrexon e. In the youngest animals, there was no treatment effect presumably d ue to low basal levels of testosterone. EtOH similarly reduced luteini zing hormone (LH), but this suppression was not prevented by naltrexon e. There was no consistent effect of any treatment on hypothalamic con centration of pro-LH releasing hormone (RH) (LHRH), LHRH, or an steady -state levels of LHRH mRNA. We conclude that, as animals progress thro ugh puberty, EtOH suppresses LH and testosterone. The testosterone dec line can be prevented by opiate blockade with naltrexone, an effect pr imarily seen at gonadal revel. Thus, naltrexone, a drug already used c linically to reduce EtOH intake, also has protective physiological eff ects on the endocrine system.