Abstract: Objective To study the effects of Norethindrone on biological features of estrogen receptor(ER), progesterone receptor(PR)and proliferative cell nuclear antigen(PCNA) in patients with simple endometrial hyperplasia(EH).Methods Thirty cases diagnosed by curettage and pathological examination were given Norethindrone 5 mg everyday for 22 days from the 5 day after curettage and 5th days from onset of second and third mentrual periods. The pathology of endometrium was examined at the 25～28 days of the third periad. ER, PR, PCNA expressions were examined with immunohistochemical methods pre-and after-treament by Norethindrone for 3 monthes.Results After three periods of treatment by Norethindrone, the menstrual durations were shortened obviously, the amount of flow and clots were decreased. The expressions of ER, PR and PCNA in simple endometrial hyperplasia before treatment were 3.33±1.92, 4.13±1.55 and 4.40±1.54 respectively. After three periods of treatment, expressions of ER, PR and PCNA were 1.97±1.87, 1.80±1.75 and 1.83±1.00 respectively, which were significantly lower than those of the pretreatment ones(P<0.05).Conclusion Norethindrone is effective in the treatment of simple endometrial hyperplasia.

Key words: endometrial hyperplasia, progesterone receptor, estrogen receptor, proliferative cell nuclear antigen, Norethindrone