Alteration in the normal pattern of serum testosterone and 5 alpha-androstane-3 alpha, 17 beta-diol in the immature male rat following chronic treatment with luteinizing hormone releasing hormone or luteinizing hormone.

A major component of sexual maturation in the male rat is a progressive decline in serum concentrations of 5 alpha-androstane-3 alpha, 17 beta-diol (3 alpha-diol) and a concomitant increase in testicular testosterone biosynthesis and secretion. Chronic administration of synthetic luteinizing hormone releasing hormone (LHRH) or luteinizing hormone (LH)/human chorionic gonadotropin (hCG) to immature male rats has been shown to result in a delay in sexual maturation as evidenced by decreased sex accessory gland weights and altered testicular testosterone production. We have examined the postulate that such treatments may either reverse or retard the normal developmental pattern of serum testosterone and 3 alpha-diol concentrations. Chronic in vivo treatment of 28 day old immature male rats for 2 weeks with daily injections of either 0.5 micrograms of LHRH, 1.0 micrograms of LHRH, or 30 micrograms of LH was found to result in significant reductions in weights of the seminal vesicles and ventral prostate glands and diminutions in serum testosterone concentrations. Serum content of 3 alpha-diol was either unchanged or slightly elevated in the LHRH treated animals and increased significantly in the LH treated animals. These data suggest that either a reversal of or retardation in the normal developmental pattern of serum testosterone and 3 alpha-diol content has been achieved in the immature male rat by chronic LHRH or LH treatment.