大豆异黄酮对围绝经期大鼠子宫作用及机制研究

目的:研究不同剂量及大豆异黄酮(SI)对围绝经期大鼠子宫以及子宫雌激素受体亚型ERα、ERβ表达的影响,探讨SI对子宫的作用及机制。方法:设7月龄雌性SD大鼠为正常组,将11月龄雌性SD大鼠随机分为五组:模型组,己烯雌酚组和3个SI给药组(分别灌胃SI30、12、4.6mg/kg·d),35d后,HE染色、扫描电镜观察子宫内膜形态,放射免疫检测血清雌二醇(E2)、卵泡刺激素(FSH)、黄体生成素(LH)、睾酮(T)含量,免疫组化观察SI对子宫ERα,ERβ表达的影响。结果:低剂量SI可提高11月龄大鼠血清雌二醇水平而高剂量SI组雌二醇水平明显低于7月龄正常组动物,各剂量SI均能促进子宫内膜腺体发育和内膜上皮无纤毛细胞上的微绒毛生长,无明显剂量依赖趋势。高剂量SI能明显提高围绝经期雌鼠子宫中降低的ERβ水平而对ERα无显著影响。结论:大豆异黄酮对围绝经期雌鼠子宫有雌激素样作用并且对ERβ表达具有调节作用。

STUDY ON EFFECTS AND MECHANISM OF SOYBEAN ISOFLAVONES ON UTERI IN PERIMENOPAUSAL RATS

Objective:To observe the effects of soybean isoflavones(SI) on uteri and uterine Erα,ERβ expression in perimenopausal rats. Method:Female SD rats in age of 7-month-old were used as control and 11-month-old SD rats were divided into 5 groups,model group,diethylstilbestrol group and 3 test groups exposed to three doses of SI(ig:30,12,4.6 mg/kg·d) respectively for 35 d. Serum concentrations of estradiol(E2) ,testosterone(T) ,follicle-stimulating hormone(FSH) and luteinizing hormone(LH) were determined. Ultrastructure of uterine luminal surface was observed by scanning electron microscopy and hematoxylin-eosin staining. Expression of ERα and ERβ in the uteri were determined by immunohistochemistry. Results:Low dose SI significantly increased serum E2(P<0.05) while it was significantly reduced when exposed to high dose SI(P<0.01) . SI exerted stimulatory effects on uterine glandular development and microvilli growth without dose-dependant effects. Expression of ERβ in the luminal epithelium was significantly up-regulated by high dose SI(P<0.01) . Conclusion:SI exert estrogenic effects on perimenopausal uteri and act as ERβregulator.