雌激素对脑缺血大鼠的神经保护作用

Neuroprotection effects of estrogn on cerebral ischemia in rats

目的 研究雌激素对脑缺血大鼠的神经保护作用与SOD及Bcl 2蛋白表达的关系。方法 30只雌性SD大鼠随机分成 3组 ,每组 10只。Ⅰ组 (假手术组 )仅打开腹腔而不切除双侧卵巢 ,每日腹腔注射生理盐水 ,连续 2周 ;Ⅱ组 (双侧卵巢切除组 )实验前 2周手术切除双侧卵巢 ,每日腹腔注射生理盐水 ,连续 2周 ;Ⅲ组 (17β E2 治疗组 )卵巢切除后给予 17β 雌二醇 (17β E2 ) 0 .1mg·kg-1,连续 2周。 30只大鼠均采用大鼠大脑中动脉阻断制成局灶性脑缺血模型。在缺血 2h、再灌注 4 8h后立即断头取脑 ,比较 3组大鼠的脑组织凋亡细胞数、SOD含量及Bcl 2蛋白的表达。结果 Ⅱ组与Ⅰ组、Ⅲ组比较 ,动物脑组织凋亡细胞数明显增多 (P <0 .0 5 ) ,SOD含量及Bcl 2蛋白的表达明显减少 (P <0 .0 5 ) ;Ⅰ组与Ⅲ组相比较上述检测指标无显著差异 (P >0 .0 5 )。结论 雌激素上调大鼠脑缺血时脑组织中SOD的含量和Bcl 2蛋白的表达与其神经保护作用有关。

Objective To study the relationship between the neuroprotective effects of estrogen and expression of Bcl-2 and SOD content in cerebral tissue of rat with cerebral ischemic injury.Method Tirty female SD rats were randomly divided into three groups.In group Ⅰ(sham-operated group),only abdominal cavity was opened without abscission of bilateral ovaria,and normal saline was given intraperitoneally for 2 weeks.In the group Ⅱ,bilateral ovariectomized and normal saline injection peritoneally were used. In group Ⅲ,bilateral ovariectomy was used and the 17-β-estradiol (17-β-E_2) was injected peritoneally for 2 weeks.In 30 rats,the local ischemia-reperfusion model were induced by occluson of left middle cerebral artery.The cerebral tissue were removed at 2h after ischemia and at 48h after reperfusion. The number of apoptotic cells,expression of Bcl-2 and SOD content were measured among three groups.Results GroupⅡ had more apoptotic cells and less SOD content and expression of Bcl-2 than that of groupⅠ and groupⅢ( P <0.05).The measured parameters as described above in groupⅢ didn't change significantly compared with those in groupⅠ( P >0.05).Conclusion The neuroprotection of estrogen is related to increased content of SOD and expression of Bcl-2 in cerebral tissue of rat with ischemia reperfusion.