Histomorphometric aspects of adult castrated rat endometrium after the use of estrogen, progesterone and tamoxifen.

The aim of this study was to analyse the morphologic and morphometric aspects of endometrium in rats receiving hormone replacement therapy with conjugated equine estrogen (CEE), medroxyprogesterone acetate (MPA) and tamoxifen (TMX). Thirty-five adults rats, 2-3 months of age were ovariectomized four days prior to using the drugs. Rats were divided according to the following treatments for 60 days: CEE (50 microg); CEE/MPA (50 microg/2 mg); MPA (2mg); TMX (250 microg); vehicle (propyleneglycol). Fragments of endometrium were removed and analysed by light microscopy. The endometrium suffered evident morphologic modifications under the action of hormones and TMX. The endometrium was significantly thicker in the CEE, CEE/MPA and TMX group when compared to the control, however the MPA group showed no differences when compared to the control group.