Changes in Nuclear Estradiol Receptor and Cell Structure During Estrous Cycles and Pregnancy in the Oviduct and Uterus of Cats

Abstract

Oviducts and uteri were removed from cats at various intervals during the estrous cycle and pregnancy. Systemic blood was drawn on the day the tissues were removed and plasma estradiol (E2) and progesterone (P) were measured by radioimmunoassay. The amounts of nuclear E2 receptor in the oviducts and uteri were determined with an exchange assay; portions of these same organs were fixed and embedded in Araldite for morphological study.