卵巢切除对大鼠子宫阴道雌激素受体亚型表达的影响

Effect on the Expression of ER Subtype in the Uterus of the Ovariectomy Rats

目的通过观察雌激素受体亚型在去势大鼠子宫和阴道的表达,研究卵巢切除对大鼠子宫、阴道的影响机制。方法60只成年SD雌性大鼠随机分为正常组、假手术组、去势组,每组20只。8周后处死大鼠,分离摘取子宫、阴道,进行ERα、ERβ免疫组织化学染色和mRNA半定量RT-PCR检测。结果ERα在各组子宫内膜上皮细胞、间质细胞及平滑肌细胞中均有表达,以内膜腔上皮和腺上皮细胞表达最强;ERα在各组阴道粘膜上皮细胞、间质细胞及平滑肌细胞中均有表达,以粘膜上皮细胞中表达最强。去势组子宫、阴道ERα表达水平较其它两组明显降低。ERβ主要在正常组和假手术组子宫内膜腔上皮细胞、腺上皮细胞和阴道粘膜上皮细胞中有表达,但较ERα表达弱。ERβ在去势大鼠子宫和阴道中未见明显表达。正常组和假手术组子宫、阴道雌激素受体亚型的表达强度和分布无明显差异。结论卵巢切除后大鼠子宫、阴道ER亚型表达明显降低,尤其以ERβ表达下调明显。

To investigate differences in the expression and distribution of estrogen receptor-alpha（ER-α） and beta（ER-β） in the uterus and vagina of rats after ovariectomy. Methods A total of 60 adult female SD rats weighing about 340g were randomly allocated into 3 equal groups： unoperated control group （n=20）, sham-operated group （n=20） and ovariectomied group （n=20）. Immunohistochemical methods were used to determine ER-α and ER-β in superficial and deep compartments in the uterus and vagina. The gene expression levels of marker genes of the two isoforms of estrogen receptor were measured by semi-quantitative RT-PCR. Results The expression of ER-α was significantly （P〈0.01） lower in ovariectomied rats in the luminal epithelium, superficial glands, superficial stroma and smooth muscle cell in the uterus, especially in the superficial gland （P〈0.05）. The expression of ER-β was only observed in the superficial glands in both treatments, obtaining the lowest levels in ovariectomied animals （P〈0.01）. There were significant differences in the ER isoforms immunostaining in the uterus and vagina in intact rats. The result of RT-PCR assay showed that ER-α was extensively expressed in uterine and vaginal tissues. Lower levels of both ER-α and ER- β mRNA were observed in the uterus in ovariectomied group （P〈0.05）. Conclusion It was demonstrated that down-regulation of ER-α and ER-β was expressed in the uterine and vaginal tissues and cells after ovariectomy. These findings may reveal a novel selective action of ER agonists and antagonists in different tissues.