The effects of human chorionic gonadotrophin on normal testicular tissue of rats: dose-dependence and reversibility.

OBJECTIVE To investigate the effect of human chorionic gonadotrophin (hCG) on rat testicular tissue, and its reversibility and dose dependence. MATERIALS AND METHODS Male Wistar rats were assigned to groups (10 rats/group) receiving 10, 30 or 50 IU/kg hCG subcutaneously once daily for 15 days; 10 controls received subcutaneous isotonic saline. At 1 and 3 months later, five rats in each group were killed and their testes removed. The testes were examined histologically to measure seminiferous tubular diameter and germinal membrane thickness. RESULTS At 1 month after hCG administration, the mean germinal membrane thickness in the testicular tissues of the hCG-treated rats was significantly less than in control rats, and was also significantly different between all of the hCG-treated groups (P < 0.05). However, at 3 months after hCG administration, all histological variables were similar to those in control rats (P > 0.05), and the mean germinal membrane thickness at 3 months after hCG administration was larger than that at 1 month (P < 0.05). There were no significant differences in the mean seminiferous tubular diameter between hCG-treated rats and control rats. CONCLUSION hCG impairs seminiferous tubule histology in the 'normal' descended testes of rats. This effect was dose-dependent, and the changes were reversed at 3 months after treatment. Thus, although hCG therapy might affect the seminiferous tubules of contralateral descended testes in cryptorchid boys, these effects might be reversible.