Comparative estrogenicity of cis and trans isomers of glomiphene citrate in rats undergoing delayed implantation

Abstract

The effects of cis̲ or trans̲ isomsrs of clomiphene citrate or estradiol-17β on uterine weight, uterine glycogen and liver glycogen were studied in rats undergoing delayed implantation. Comparative estrogenicity of the cis̲ or trans̲ isomers with estradiol-17β was assessed with reference to changes in uterine glycogen and liver glycogen in response (a) to different doses of the isomers i.e. 150, 300 or 1SOO gmg/kg and (b) to a small dose (150 gmg/kg) of the compound at different time intervals (6, 18 and 48 hours). High doses of cis̲ clomiphene increased uterine weights more than trans̲ clomiphene. Neither of the two isomers, in small doses, caused any change in uterine weights at any of the time intervals studied. Trans̲ clomiphene caused an increase in glycogen concentration in the uterus and liver 18 hours after the administration of the drug whereas a similar increase was not seen with the highest dose (1800 gmg/kg) of the cis̲ isomer administered. It is concluded that the trans̲ isomer of clomiuhene citrate is more estrogenic than the cis̲ isomer using glycogen as an estrogen sensitive parameter, whereas clomiphene is more uterotropic than the trans̲ isomer at higher doses.