雌激素及植物雌激素对去卵巢大鼠乳腺组织形态和ERα亚型表达的影响

目的探讨雌激素及植物雌激素对去卵巢大鼠乳腺组织形态和ERα亚型表达的影响,并比较雌激素和植物雌激素作用的异同。方法48只Wistar大鼠随机分为8组,分别为假手术组(Sham)、去卵巢组(Ovx)、17β-雌二醇组(Ovx+Est)、17-β雌二醇+黄体酮组(Ovx+Est+Pro)、黄体酮组(Ovx+Pro)、染料木素组(Ovx+Gen)、白黎芦醇组(Ovx+Res)、根皮素组(Ovx+Phl)。对应组给药21d后处死,取乳腺组织,用蛋白免疫印迹法观察各组大鼠乳腺ERα的表达、并利用免疫组化对其形态学变化进行观察。结果乳腺组织中的ERα主要位于乳腺导管上皮细胞的胞质和胞核内。ERα在8组中均可表达,但表达量却不同。Sham与Ovx比较,Ovx组ERα表达上调(P<0·05);Ovx与Ovx+Est、Ovx+Pro、Ovx+Gen、Ovx+Res、Ovx+Phl比较,后5组ERα表达均下调(P<0·01);Ovx与Ovx+Est+Pro比较则差异无显著性(P>0·05);大鼠卵巢切除后,乳腺明显萎缩。卵巢切除大鼠皮下分别注射Gen和Phl后,乳腺结构仍呈现出卵巢切除后的表现。皮下注射Res乳腺腺泡及其上皮细胞有不同程度的增生。皮下注射Est或Est合并Pro后,乳腺组织密度增加,乳腺上皮细胞明显增生。结论植物雌激素Gen、Phl和Res与雌激素相似,可以下调去卵巢切除大鼠乳腺组织ERα的表达;Res还可促进去卵巢切除大鼠乳腺上皮细胞增生,但作用不如雌激素强。

Effects of estrogen and phytoestrogens on the morphology and ERα expression in breast tissue of ovariectomized rats

Aim To study the effects of estrogen and phytoestrogens on the ERα expression and morphology in breast tissue of ovariectomized rats and to compare the actions of phytoestrogens with that of estradiol. Methods 48 Wistar rats were randomly divided into 8 groups: Sham, Ovariectomized (Ovx), 17β-estradiol (Ovx+Est), 17β-estradiol+Progesterone (Ovx+Est+Pro), Progesterone (Ovx+Pro), Genistein (Ovx+Gen), Resveratro (Ovx+Res), Phloretin (Ovx+Phl). After treated for 21 days, all rats were killed, their breast tissues were removed, the expressions of ERα were examined by the Western blot, and also the morphological changes in breast tissues were observed by immunohistochemical method. Results The ERα in breast tissue mainly sited in cell endochylema and nucleus. ERα was expressed at different level in eightgroups. To compare sham with Ovx group, the expression of ERα was up-regulated in Ovx rats (P<0.05). However, to compare Ovx+Est, Ovx+Pro, Ovx+Gen, Ovx+Res and Ovx+Phl rats with Ovx group respectively, the expressions of ERα were all down-regulated (P<0.01). After bilateral ovariectomy, the rat breast atrophied. After injected Gen and Phl subcutaneously, the Ovx rat breast had no change in morphology, but administration of Res could proliferate the breast alveoli and its epithelial cell. After treatment with Est or Est+Pro, the breast had obvious proliferation and its histological density increased. Conclusion Similarly to Est and Pro, phytoestrogens Gen, Res and Phl can down-regulate the expressions of ERα in Ovx rats, and Res can also change the morphological features of breasts, but its action is weaker than that of Est.