Effects of C21Steroids on Sex Accessory Organs and Testes of Mature Hypophysectomized Rats1

Adult hypophysectomized male rats were treated with 2 mg/day of testosterone propionate, pregnenolone, 17alpha-hydroxypregnenolone, progesterone or 17alpha-hydroxyprogesterone. The treatment commenced on the day of surgery and was continued for 4 weeks. In all steroid treated animals, spermatogenesis was qualitatively maintained. Sex accessory organs were maintained only in testosterone propionate treated animals. In C21 steroid-treated rats the sex accessory organs showed atrophy similar to untreated hypophysectomized animals suggesting lack of peripheral conversion to androgens. However, administration of 3H-pregnenolone with the last injection of pregnenolone resulted in the isolation of a considerable amount of 3H-testosterone from testicular tissue of the experimental animals. This finding suggests that maintenance of spermatogenesis in pregnenolone treated animals could have been due to testosterone formed in the testes from the exogenously administered pregnenolone.