| Abstract: | Centchroman (3,4-trans-2,2-dimethyl-3-phenyl-4-p-(beta-pyrrolidinoethoxy) -phenyl-7-methoxychroman), a nonsteroidal contraceptive developed by the Central Drug Research Institute, Lucknow, India, was administered orally (1.25 mg/kg) to rats in a state of experimentally delayed implantation both during the progesterone treatment (preattachment stage) and in conjunction with the addition of estradiol (attachment stage). When given during preattachment, centchroman did not change the characteristic ultrastructure of the uterine epithelium significantly, except that there was an increase in the size and number of secondary lysosomes. Thus, no definite estrogenic or antiprogestational potency of centchroman was observed in this test system. However, when administered simultaneously with, before, or after estrogen during attachment, centchroman both abolished the estradiol-induced attachment reaction and produced or potentiated some changes of an estrogen type. Thus, no typical antiestrogen action but the sign of an estrogen action was observed in this test system. Further, the drug also produced certain specific changes in the lysosomal system of the epithelial cells during attachment. It is suggested that, in addition to some estrogenic effects, centchroman also possesses specific cellular effects, probably of a nonhormonal nature. |
