Temporal and spatial expression of estrogen receptor in the endometrium of patients with endometriosis,adenomyosis or both

Objective: For exploring the etiology of the endometriosis and adenomyosis, the expression patterns of estrogen receptor α and β in different cell types of endometrium in patients with endometriosis, adenomyosis or both during menstruation cycle were compared to the control endometrium. Methods: One hundred and eight endometrial samples were obtained from normal uterus as control, and from patients with endometriosis, adenomyosis or both by laparoscopy or hysterectomy. According to the Noyes’ dating criteria, the actually stages of endometrial samples were determined by HE staining sections. The temporal and spatial expression of estrogen receptor α and β in the epithelial cells, stromal cells and endothelial cells of spiral artery in the eutopic endometrium from endometriosis, adenomyosis or both during menstruation cycle was compared to the normal endometrium by immunohistochemistry.Results: The expression intensity of ERα in endometrium of patients with endometriosis or adenomyosis was mostly parallel with that of normal endometrium. But the ERα positive signal frequency increased evidently either in glandular epithelial cells, or in stromal cells or in the vascular endothelial cells in the endometriosis and adenomyosis. The ERα positive signal occurred even more in the patient’s cytoplasm of glandular epithelial cells. The vascular endothelial cells with positive staining were arising mostly through out the menstrual cycle in the groups with endometriosis or adenomyosis. No significant difference was found in ERβ between the groups of patients and control. Conclusion: The regulatory effects of estrogen may be mediated mainly via ERα rather than ERβ in human endometrium. The elevation of signal frequency in glandular epithelial cells, stromal cells and vascular endothelial cells as well as the widespread expression of ERα in the cytoplasm of glandular epithelium may cause endometriosis and adenomyosis. ERβ might not be involved in the cause of endometriosis and adenomyosis.