NORETHISTERONE OXIME: ESTROGENICITY AND ANTI-IMPLANTATION / 中国药理学通报

ABSTRACT

Several comparative studies on anti-implantation and estrogenicities of noret histerone oxime(NETO)and norethisterone(NET) or ethynyl estradiol (EE2)were carried out in order to clarify their relationships. It was observed that NETO was showed much stronger potency than NET, which the anti-implantation, uterotrophic and vaginal cornifi-cation effect were 25, 26, and 21 times, respectively. The ratio of anti-implantation to vaginal cornification of NETO was 14-fold stronger than that of EE2. These results suggest that the increased antiimplantative activity of NETO is related to its stronger estrogenic activity, but other mechanisms contribute to the anti-implantation besides estragenicity.