Fundamental differences in the action of estrogens and antiestrogens on the uterus: comparison between compounds with similar duration of action.

摘要: In order to understand differences in the mechanism of action estrogens and antiestrogens, it is essential make comparisons between compounds with similar duration action. Hence, these studies, we compare a longacting estrogen (17α-ethinyl estriol-3-cyclopentyl ether, EE3CPE) long-acting antiestrogen (U-ll,100A, UA) on immature rat uterus analyze different dosage regimens (single multiple injections) studying effects uterine receptor growth sensitivity estradiol. During first 24 h, UA (50 μg) EE3CPE (5 evoke remarkably distribution patterns wet weight increase; however, pronounced are seen longterm, injection (every 12 or h for 72 h). Such treatment results maintenance high nuclear levels very low cytoplasmic (ca. 10% total), but no further increase weight, DNA p...