Histochemical Studies of Hydroxysteroid Dehydrogenase Activity in Mammalian Reproductive Tissues12

Abstract

Hydroxysteroid dehydrogenase activity was studied histochemically in the ovary and placenta of the rat, rabbit, guinea pig, cow and human, and in the testis of the rat. Hydroxysteroids with the 3α, 3β, 17α, 17β, 20α and 20β configurations were used. The 3β-hydroxysteroid dehydrogenase activity was observed in the theca interna, corpus luteum and interstitial cells of the ovary, in the Leydig cells of the rat testis, in the syncytial trophoblast of the human placenta, and in the trophoblastic giant cells of the rat and guinea pig. The luteal cells of the rabbit showed less activity than did the interstitial cells except in early pregnancy, when their activities were equal. The cow placenta was negative. Activity with 17β-hydroxysteroids was found only in the ovary of the guinea pig and in the human syncytial trophoblast. No 20α- or 20β-hydroxysteroid dehydrogenase activity was observed. Increasing the alkalinity of the incubation medium to pH 9.5 or substituting TPN for DPN did not alter the results. (Endocrinology78: 667, 1966)