<i>In Vitro</i>Conversion of 7-³H-progesterone to Androgens by the Rat Testis During the Second Half of Fetal Life

Abstract

Testes from rat embryos of 13½-21½ days of age were incubated with 7-3H-progesterone. The radioactive testosterone and androstenedione produced were estimated using the double isotope dilution method. The capacity of the tissue to convert progesterone to androgens increased sharply at 15½ days, that is, at about the time of differentiation of the accessory reproductive system. Conversion was maximal at 18½ days and was maintained at this level through the first postnatal day. The effects of tissue:substrate ratio, TPN and duration of incubation as well as of intrauterine decapitation of the fetus on the production of androgens were also studied. The relationship of the findings to sexual differentiation is discussed. (Endocrinology78: 245, 1966)