The effect of long-term variation in sympathetic activity on testicular morphology in immature rats.

In order to investigate the effect of increased and decreased sympathetic activity on testicular development, immature male rats were injected with isoproterenol or 6-hydroxydopamine from birth up to 49 days of age. Isoproterenol treatment resulted in a marked Leydig cell hypertrophy but the development of the spermatogenic epithelium was unaffected compared to that in saline treated controls. 6-hydroxydopamine treatment in a dose inhibiting the development of the parotid gland did not influence testicular development.