Dissociation kinetics of the uterine estrogen receptor-estradiol complex are unaltered in aging C57BL/6 mice.

Several, though not all, estrogen-dependent phenomena show reduced responsiveness to estradiol (E2) during aging. One factor contributing to this reduced sensitivity could be an increase in the dissociation rate of the estrogen receptor-hormone complex. We therefore studied the effect of aging on the dissociation rate of 3HE2 from the uterine cytosolic estrogen receptor (ER) of C57BL/6 mice that had been ovariectomized 48 h earlier.

Up-regulation of the uterine estrogen receptor and its messenger ribonucleic acid during the mouse estrous cycle: the role of estradiol.

Uterine estrogen receptor (ER) and ER mRNA were measured in cycling and ovariectomized (OVX) estrogen-treated mice to probe the physiological regulation of the intracellular distribution and biosynthesis of ER. On proestrus, when plasma estradiol (E2) levels are highest, the cell nuclear ER concentration was 2.4-fold greater than on metestrus.