Steroid secretion by the prepubertal human testis.

It has been demonstrated that the human testis secretes testosterone and, to a smaller extent and less constantly, also androstenedione. Testosterone, progesterone, 17 alpha-hydroxyprogesterone and 20 alpha-dihydroprogesterone have been measured in the spermatic and peripheral venous blood of prepubertal boys undergoing surgery for undescended testis or inguinal hernia repair. The spermatic plasma levels of testosterone and progesterone were significantly higher than peripheral levels. A significant spermatic-peripheral gradient was not found for 17 alpha-hydroxyprogesterone and 20 alpha-dihydroprogesterone. These studies demonstrate that the secretory pattern of the human prepubertal testis is different from that of the adults.