Seasonal fluctuations of the testicular androgenic function in rats

Testicular steroid-delta 5-3 beta-ol-dehydrogenase activity and plasma testosterone level in pubertal Wistar rats in spring and summer are 2-4 times higher than in autumn and winter. On the contrary the weight of the ventral prostate and seminal vesicles is lower in summer as compared with that in other seasons. This divergence is probably caused by fluctuations of the glandular secret content.