Short-term response of testosterone, dihydrotestosterone, 5 alpha-androstane-3 beta, 17 beta-diol, testosterone-glucosiduronate and estradiol-17 beta as measured in the spermatic vein of human male subjects after infusion of gonadotropins.

In 8 male subjects with normal testicular function, blood was drawn from the left spermatic vein and from the right cubital vein before and during an infusion of 4,000 IU human chorionic gonadotropin (hCG) (preceded by a bolus of 1,000 IU) or of 500 IU hCG plus human menopausal gonadotropin (hMG), respectively, within 30 min. Testosterone levels in the spermatic vein blood increased rapidly up to 518 or 215%, respectively. An increase of estradiol-17 beta and of 5 alpha-dihydrotestosterone concentrations in spermatic vein blood was observed only in 1 and 2 subjects, respectively. It was shown that the human testicle releases also 5 alpha-androstane-3 alpha, 17 beta-diol and testosterone-glucosiduronate. Both steroids did not respond to the short-term infusion of gonadotropins. The same holds true for all five steroids measured in peripheral vein blood.