Correlative changes of plasma renin activity and serum testosterone in human internal spermatic vein after single administration of human chorionic gonadotropin.

To study changes in renin secretion from the human testis at various days after hCG treatment, plasma renin activity in the internal spermatic vein (ISV) and cubital vein (CV) was measured at the time of surgical repair of varicocele in 79 patients. Sixty-five of them were given a single administration of hCG (10,000 IU/m2) 1 to 10 days before operation. Although the mean PRA levels in CV in both treated and untreated groups were similar, the mean PRA levels in ISV obtained 1 to 5 days after hCG treatment were significantly higher than that in the untreated group. However, the mean PRA levels in ISV returned to that in the untreated group 6-10 days after treatment. Serum testosterone levels in the same ISV were also much higher 1 to 6 days after hCG treatment, compared with those in the untreated group. On the basis of these results it is concluded that (a) the secretion of renin from the testis into ISV can be demonstrated for 5 days after hCG treatment; (b) the parallel increases in PRA with testosterone in ISV seem to suggest a possible influence of androgen on renin production in Leydig cells of human testis.