OBJECTIVETo observe the statuses of estrogen receptor (ER) alpha and beta in the pelvic floor and its relation with stress urinary incontinence (SUI).

METHODSThe ERa and ERP in levator ani muscle and pelvic floor structure of premenopausal and postmenopausal SUI patients were detected by immunohistochemical staining and Western blot.

RESULTSThe positive biopsy rates in the premenopausal and postmenopausal SUI groups were 11% and 0, and the corresponding results in the control group were 35% and 33%. No ERalpha and ERbeta expression was detected in the levator ani muscle. ERalpha and ERbeta located in pelvic fasia tissue around the levator ani muscle. ERbeta was negatively stained in some segments of pelvic fasia tissue. The positive expression rates of ERbeta in the pelvic fasia tissue of premenopausal and postmenopausal SUI group were 57% and 33%, which were significantly lower than those in the control groups (P < 0.05). The positive expression rate of ERP in the pelvic fascia was significantly lower in postmenopausal group than in the premenopausal group (P < 0.05). The positive expression rates of ERa in the pelvic fasia tissue in the premenopausal and postmenopausal SUI groups were (4.43 +/- 2.64)% and (5.14 +/- 1.79)%, which were significantly lower than (9.61 +/- 5.48)% and (10.88 +/- 2.90)% in control group (P < 0.05). Western blot showed that ERbeta expression in pelvic fasia tissue was less than the expressions of ERalpha, ERalpha and ERbeta in the SUI group was also lower than that of the control group.

CONCLUSIONERalpha and ERbeta do not express in the levator ani muscle of women. Pathogenesis of premenopausal SUI correlates with lower serum estrodiol level and the expression of ER correlates SUI.