戊酸雌二醇对去势大鼠子宫雌激素受体亚型表达的影响

目的　观察雌激素受体亚型在去势大鼠子宫和阴道的表达。　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，其中以子宫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，其中以阴道粘膜上皮细胞中表达最强。去势组子宫、阴道ERα表达水平较正常组及假手术组明显降低(P<0.05)。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（P<0.05）。ERβ在去势大鼠子宫和阴道中未见明显表达（P<0.01）。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(P>0.05)。　结论　大鼠去势后子宫、阴道ER亚型表达明显降低，尤其以ERβ表达下调明显。

Effect of estradiol valerate on the expressions of estrogen receptor subtypes in the uterus of the ovariectomizedrats

Objective 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-αand ER-βin 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-αwas 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-αand βmRNA were observed in the uterus in ovariectomied group (P<0.05). Conclusion It was demonstrated down-regulation of ER-α and ER-β expression 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.