Testosterone Synthesis by the Fetal Rabbit Gonad

Abstract

The synthesis of testosterone from pregnenolone and androstenedione was measured at several intervals during gestation and after parturition. Testosterone synthesis was demonstrated in the fetal testis on the eighteenth day of gestation before Leydig cells could be identified. The extent of conversion of pregnenolone to testosterone increased during gestation and decreased after parturition. At all points, the fetal testis had a greater capacity for testosterone synthesis than did the fetal ovary. (Endocrinology77:273, 1965)