BIOCHEMICAL AND HISTOLOGICAL EFFECTS OF VAGINAL ESTRIOL AND ESTRADIOLAPPLICATIONS ON THE ENDOMETRIUM, MYOMETRIUM AND VAGINA OF POSTMENOPAUSAL WOMEN

Estrogen and progesterone receptors in the cytosol (ERc, PRc) and estr ogen receptors in the nuclear compartment (ERn) were measured in the e ndometrium, myometrium and vagina of 29 postmenopausal women who under went hysterectomy. The effects of vaginal estriol (0.5 mg daily) compa red to 17 beta-estradiol (0.05 mg daily) therapy on these receptor lev els were studied. In addition, the endometrium was examined by light m icroscopy for estrogenic stimulation. We found biochemical and histolo gical signs of estrogenic stimulation in all three tissues after estra diol as well as estriol therapy. In the vagina the effect of both estr ogens on the ERc concentration was different from that in the endometr ium and myometrium. The effects of estradiol and estriol on the ERn we re comparable in all three tissues. The PRc levels increased significa ntly in all tissues after estrogen therapy; in the myometrium it was s ignificantly higher after estriol that after estradiol applications. I n conclusion, there were no clear differences between vaginal estradio l and estriol medication with regard to the effects on receptor levels in vaginal and uterine tissues. In the histological studies at the li ght microscopy level similar signs of estrogen stimulation of the endo metrium were found following estradiol and estriol medication.