Immuno-electron microscopic localization of estradiol receptor in cells of male and female reproductive and non-reproductive organs.

The localization of estradiol receptor (ER) in various tissues and their distribution in sub-cellular compartments were studied by means of immunogold-electron microscopic methods using a site-directed polyclonal antibody developed against a peptide from the DNA binding site of ER. This method was used to determine the presence and localization of ER in tissues and cells of male and female reproductive and non-reproductive organs. In the female reproductive tract, endometrial cells and the cells of the corpus luteum were found to contain ER. In non-reproductive organs of both sexes the following cell types showed significant labeling: hepatocytes, epithelial duodenal cells, striated muscle fibers, cells of the proximal convoluted tubules of the kidney, lymphocytes, neurons, and adipose cells. Alveolar epithelial cells were studied only in female specimens and were labeled by the anti-ER. Prostatic and epididymal epithelial cells were found to be labeled in the male reproductive organs. In all these cells a higher density of label was found in the nucleus, especially in the space between the clumps of compact chromatin, as was previously found in epithelial endometrial cells. These results suggest that estradiol exerts its effects through a common nuclear mechanism in cells of male and female reproductive and non-reproductive organs.