Prostaglandins masculinize the mouse genital tract

The masculinizing effects of prostaglandins (PGS) PGE2 and PGF2 alpha on mouse fetal genital tract differentiation were studied both in vivo and in vitro. Prenatal exposure to PGE2 and PGF2 alpha on days 11-17 of gestation (the critical period of the differentiation) increased the anogenital distance of the female fetuses in a dose-dependent manner. PGE2 also increased the anogenital distance of male fetuses in the presence of an inhibitor of testosterone synthesis, namely estradiol (2 mg/kg.day), and in the androgen-insensitive Tfmy males. Internally, PGE2 induced the epididymal duct in the females, estrogen-exposed males, and Tfmy males. However, no other changes were noticed in the internal genital tract of these fetuses. To avoid the problems associated with the placental transfer of any external agent, we also studied the effect of PGE2 in an in vitro system. Female genital ducts on day 13 of gestation were cultured in the presence and absence of different concentrations of PGE2 for a total of 6 days. PGE2 at doses 0.2 and 1 microgram/ml induced and stimulated the Wolffian and epididymal ducts. Thus, PGs appear to have a masculinizing role in androgen-induced sexual differentiation.