植物雌激素染料木素抗去卵巢大鼠海马血管内β-淀粉样蛋白沉积研究

Effects of Genistein on Deposition of Beta-amyloid Protein in Blood Capillaries of Ovariectomized Rat Brain

目的观察雌激素缺乏大鼠海马血管内β-淀粉样蛋白(beta-amyloid protein,Aβ)沉积的变化,并比较研究植物雌激素染料木素干预对Aβ沉积的影响。方法本研究采用双侧卵巢切除术建立SD雌鼠的去势模型,将50只大鼠随机分为五组:正常对照基线组(Baseline组)、假手术组(Sham组)、去卵巢组(Ovx组)、染料木素干预组(Gen组)和小剂量17β-雌二醇干预组(Est组)。所有大鼠均在术后15周处死,取海马结构切片进行免疫组织化学技术观察Aβ沉积。通过Aβ阳性细胞计数和染色图像灰度分析法观察Aβ沉积的变化。结果Ovx组大鼠海马血管内Aβ阳性细胞计数和Aβ沉积的免疫组化图像灰度校正数据显著高于Baseline组、Sham组、Est组和Gen组(P<0.01);而Est组、Gen组、Sham组和Baseline组的细胞计数和图像灰度校正数据之间无显著差异(P>0.05)。结论长期内源性雌激素的缺乏可以导致脑内毛细血管内Aβ的沉积增加;染料木素或17β-雌二醇补充治疗均可以拮抗这一过程,且二者之间的效果相似。

Objective To investigate and compare the effects of 17 beta - estradiol or genistein on the deposition of Aβ in the blood capillaries of the estrogen - deficient rat brain. Methods Long - term endogenous - estrogen - deficiency models of SD rat were established by bilateral ovariectomy. Fiftly healthy SD rats were randomly divided into 5 groups： normal control group （Baseline）, sham - operated group （Sham）, ovariectomized group （Ovx）, Ovx with genistein intervention group （Gen） and Ovx with 17beta - estradiol intervention group （Est）. The rats of the 5 groups were sacrified at the 15^thweek after operation. The expressions of Aβ were showed by the application of the immunohistochemical technique, and investigated by the cell counting and imaging system analysis. Results The numbers and gray scale of the deposition of Aβ- posi- tive cells in the blood capillaries of the hippocampuses in the Ovx group were higher than those in the other four groups, i.e. Baseline, Sham, Gen and Est groups （P〈 0.01）, But the numbers and gray scale of Est group, Gen group, Sham group and Baseline group showed no statistical difference （P〉0.05）. Conclusions A long- term deficiency of the endogenous estrogen can lead to a significant increase of Aβ deposition in brain blood capillary, whereas both the 17beta- estradiol inter- vention and the genistein intervention can prevent it, and the effects of the two interventions are similar.