Estradiol Secretion by Tadpole Ovaries Masculinized by Implanted Capsules of Cyanoketone: (cyanoketone/estradiol secretion/Δ -3β-HSD activity/masculinized ovary/Rana tadpole).

Female tadpoles of Rana catesbeiana were laparotomized at metamorphic stages XI-XIII and an empty capsule or one containing cyanoketone (CK), which is an inhibitor of Δ -3β-hydroxysteroid dehydrogenase (Δ -3β-HSD), was implanted intraperitoneally. Ovarian activity of Δ -3β-HSD was examined histochemically 2 months later, estradiol-17β (E ) secretion by the ovaries was measured by RIA 4 months later and histological changes of the ovaries were examined 6 months later. The Δ -3β-HSD activity of the CK-treated ovaries was much lower than that of controls.