Antifertility Activities of Two Diphenyl-Dihydronaphthalene Derivatives

Abstract

U-10520A and U-11100A, derivatives of 1,2-diphenyl-3,4-dihydronaphthalene, possess oral antifertility activity in rats, guinea pigs, and rabbits. Efficacy, following daily doses as low as 5 μg, is restricted to first 4 days of pregnancy. Antifertility activity has not been observed in hamsters. These compounds cause minimal uterotropic stimulation and also inhibit estradiol-induced uterine weight increases. Gonadotropin inhibiting activity is not observed at therapeutic doses. In contrast to many compounds reported to effectively inhibit pregnancy, both U-10520A and U-11100A possess very favorable therapeutic ratios.