Tissue and intracellular distribution of estradiol receptors in the uterine endometrium.

A study of the tissue and intracellular distribution of estradiol receptors was made of the uterine endometrium of the rat, using an immunofluorescence technique. It was found that nearly all cells of the uterine gland have a uniform distribution of receptors, which does not change throughout the sexual cycle from proestrus to estrus. In contrast, a dense pattern of distribution of estradiol receptors was seen in the endometrial stroma during proestrus, whereas a diffuse pattern was seen during estrus. Intracellularly, the transition from the cytoplasm to the nucleus of estradiol reacting to receptors was found to be positively correlated with the incubation temperature and the length of incubation.