Аннотация:The concentration of receptors to E2 decreased in the uterine cytoplasm of rat uterus and increased in the nuclei during sexual maturation. With ageing this index in the cytoplasm and the nuclei of the uterus fell, and failed to alter during pregnancy. After ovariectomy the concentration of the receptors increased in the uterine cytoplasm, but no marked changes in the receptors occurred in the nuclei. No significant changes were revealed in the receptors to E2 in sexual maturation, pregnancy and ovariectomy in the cytoplasm and the nuclei of the kidneys and the liver. Administration to rats of E2 produced a reduction of the concentration of receptors to E2 in the cytoplasm of the uterus, kidneys and the liver and an increase in their content in the nuclei of the uterus and the liver.