229 Effects of peroxisome proliferator activated receptors- and - agonists on estradiol-induced proliferation and hyperplasia formation in the mouse uterus A G Gunin, A D Bitter, A B Demakov, E N Vasilieva and N V Suslonova Department of Obstetrics and Gynecology, Medical School, Chuvash State University, P.O. Box 86, Cheboksary 428034, Russia (Requests for offprints should be addressed to A G Gunin; Email:
[email protected]) Abstract It is suggested that the action of peroxisome proliferator- animals treated with estradiol and rosiglitazone for 30 days, activated receptors (PPARs) cross-talks with estrogen uterine mass was increased, abnormal uterine glands and signaling in the uterus. However, it is not known how atypical endometrial hyperplasia were found more often PPAR agonists affect estrogen-dependent processes in and levels of estrogen receptors- and -catenin were the uterus, especially proliferation and morphogenetic decreased. In animals treated with estradiol and fenofibrate changes. The effects of agonists of PPAR- and - on for 30 days, uterine mass was decreased, most of the proliferative and morphogenetic reactions in the uterus uterine glands had a normal structure, no cases of atypical under short- and long-term estrogen treatments were hyperplasia were diagnosed, proliferative activity was therefore examined. Ovariectomized mice were treated declined and the levels of estrogen receptors- and with estradiol dipropionate (4 µg/100 g, s.c., once a week) -catenin were markedly higher. Treatment with rosi- or vehicle and rosiglitazone (PPAR- agonist) or fenofi- glitazone or fenofibrate did not affect the serum estradiol brate (PPAR- agonist) or with no additional treatment level in the mice which received estradiol together with for 2 days or for 30 days.