Estrogen action in the mouse uterus: differential nuclear localization of estradiol in uterine cell types

Autoradiographic studies of labeled steroid uptake in mouse uterine tissue indicated that labeled estradiol was predominantly sequestered in the nuclei of stromal and glandular epithelial cells at 1 h. Luminal epithelial cells did not show appreciable nuclear accumulation of labeled estradiol until 7-8 h after hormone injection. Studies using non-target tissues and unlabeled steroids indicated that the nuclear uptake events were tissue and estrogen steroid specific. The temporal pattern of steroid hormone uptake in the uterus would suggest that an initial interaction in stromal and glandular epithelial cells may be required prior to nuclear stimulation in the luminal epithelial target cell.