Study on Estrogen Receptors in Uterine Ligaments of Premenopausal and Postmenopausal Patients With Normal Pelvic Floor

Abstract

In Brief Objective: To explore the impact of menopause on estrogen receptors α and β (ER α and ER β) in the cardinal and uterosacral ligaments in both premenopausal and postmenopausal patients with clinically normal pelvic floor support. Methods: Cardinal and uterosacral ligament tissue samples were obtained from 12 premenopausal and 8 postmenopausal patients undergoing hysterectomy. No patients had symptoms of pelvic floor disorders as determined through medical history, gynecologic examination, stress test, and urodynamic examination. They had normal menses before menopause and did not take any hormones in the 3 months prior to the study. The ER α and ER β in cardinal and uterosacral ligaments were measured by immunohistochemical staining and Western blotting. Results: ER α stained positively in both cardinal and uterosacral ligaments of all premenopausal and postmenopausal patients with normal pelvic floor. There was no significant difference in ER α positive staining in the cardinal and uterosacral ligament between premenopausal and postmenopausal women (P > 0.05). ER β stained negatively in some part of the cardinal and uterosacral ligaments. Positive staining rate of ER β in the uterine ligament is significantly lower in postmenopausal women than in premenopausal women (P < 0.01). The quantitative positive staining of ER α and ER β in the uterine ligaments is not related to menopausal status. The result of ER α and ER β by Western blotting method was similar to the result of ER α and ER β by immunohistochemical staining. Conclusions: 1) The ER β positive staining in the uterine ligaments is lower than ER α. 2) The positive staining rate of ER β in the uterine ligaments is significantly reduced in postmenopausal women. 3) ER α and ER β show different functional characteristics in uterine ligaments. ER β may play a more important role in occurrence of pelvic floor dysfunction relating to menopause. Estrogen receptor α (ERα) and estrogen receptor β (ERβ) in uterine ligaments are influenced by the patient's menopausal status.