Effects of quercetin on uterine fluid volume and aquaporin (AQP) expression in the uterus were investigated. Estradiol (E) or estradiol followed by progesterone (E+P) were given to ovariectomised rats with or without quercetin (10, 50 or 100mg/kg/day) treatment. Uteri were harvested and its inner/outer circumference ratio was determined. AQP-1, 2, 5 and 7 mRNA and protein levels in uterus were quantified by Real-time PCR and Western blotting respectively. Protein distribution was observed by immunohistochemistry. Administration of quercetin in E-treated rats decreased the uterine fluid volume and uterine AQP-2 expression. In E+P-treated rats, administration of 100mg/kg/day quercetin increased uterine fluid volume, AQP-1 and 2 expression but decreased AQP-7 expression in uterus. AQP-1 was distributed in stromal blood vessels while AQP-2, 5 and 7 were distributed in uterine epithelium.
CONCLUSIONS: Quercetin-induced changes in uterine fluid volume and AQP subunits expression in uterus could affect the uterine reproductive functions under different sex-steroid influence.