Changes in the immunolocalization of estrogen and progesterone receptors in the endometrium of the sand rat during the estrous cycle

Abstract

Objective The aim of this work was to characterize the reproductive function of a diurnal rodent, the fat sand rat, considered such as a model for studying several metabolism diseases. Uterine preliminary immunohistological results are presented. Materiel et methods After antigen retrieval, immunohistochemistry method was applied on paraffin embedded uterine. Results At estrus and diestrus, labeling of ERs was in the cytoplasm of all epithelial cells ; in metestrus, labeling became both nuclear and in the cytoplasm with few unlabeled cells, the stroma was slightly labeled ; at proestrus label for ERs and PRs was localized in the nuclear fraction. During estrus, PRs, were localized in the nuclear fraction of epithelial and stroma cells; in the lining epithelium, predominate cells were labeled while glandular cells remained immunonegative; in the stroma, labeled cells predominated. In metestrus, labeled PRs were nuclear and cytoplasmic in epithelial cells and only nuclear in the stroma. At diestrus, lining and glandular epithelial cells were completely immunonegative; labeled PRs persisted in the stroma. At proestrus, two cases were observed : negative staining of epithelial tissue and positive in the nuclear fraction of stroma cells in some female and nuclear positive staining of the epithelial and stroma cells in other females. Conclusion The localization of ERs and PRs varied during the cycle, therefore estradiol and progesterone act at different uterine compartment during the estrous phases. Functional modifications correlated with receptors localization will be presented.