title: Biological activity of some steroidal compounds in the adult and larval frogs.
abstract: Four steroids were tested for their biological activity, using the sex-steroid-dependent redevelopment of the secondary sex characteristics in adult frogs and gonadal sex differentiation in larval frogs as end points. In adult frogs, 19-norprogesterone and 6-chloro-17alpha-hydroxy-4, 6-pregnadiene-3,20-dione had antiandrogenic and antiestrogenic effects. 2alpha, 17alpha-Dimethyl-DHT and 2alpha-methyl-DHT were potent androgens and effective antiestrogens. In the larval frogs, all four compounds had a masculinizing effect upon the undifferentiated gonads.
mesh_terms: D000818:Animals; D001001:Anura; D001681:Biological Assay; D002715:Chlormadinone Acetate / Q000494:pharmacology; D003534:Cyproterone / Q000494:pharmacology; D013196:Dihydrotestosterone / Q000031:analogs & derivatives / Q000494:pharmacology; D005260:Female; D007814:Larva / Q000187:drug effects / Q000502:physiology; D008297:Male; D009653:Norprogesterones / Q000494:pharmacology; D011893:Rana esculenta; D012727:Sex Characteristics; D012733:Sex Differentiation / Q000187:drug effects*; D013256:Steroids / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D013629:Tamoxifen / Q000494:pharmacology; D013739:Testosterone / Q000494:pharmacology
chemical_list: D009653:Norprogesterones; D013256:Steroids; D013196:Dihydrotestosterone; D013629:Tamoxifen; D002715:Chlormadinone Acetate; D013739:Testosterone; D003534:Cyproterone