雌二醇对大鼠脑缺血/再灌注损伤脑组织bcl-2、caspase-3表达的影响

Effects of estradiol on expression of bcl-2,caspase-3 in ischemia-reperfusion brain tissue in rats

目的:观察雌二醇对大鼠脑缺血/再灌注损伤脑组织bcl-2、capase-3表达的影响。方法:Wistar大鼠72 只,随机分为假手术组、局灶性脑缺血2h/再灌注3h、6h、12h、24h组及雌二醇治疗(100μg/kg)+脑缺血2h/再 灌注3h、6h、12h、24h组,每时间点8只,假手术组8只。采用线栓法建立大鼠局灶性脑缺血/再灌注损伤模型,采 用连续切片免疫组化技术检测脑组织中bcl-2、caspase-3表达部位及数量。结果:雌二醇治疗组皮层bcl-2免疫阳性 细胞数与脑缺血/再灌注及假手术组比较,在再灌注后12h、24h增高,而纹状体bcl-2免疫阳性细胞数与脑缺血/ 再灌注组及假手术组比较差异无统计学意义。假手术组无caspase-3表达,雌二醇治疗组caspase-3阳性细胞数,在 皮层12h、24h明显减少,纹状体区caspase-3阳性细胞数治疗组各时间点稍减少,但与脑缺血/再灌注组比较无统 计学意义。结论:雌二醇治疗可以诱导皮层bcl-2表达及下调caspase-3活性。

Aim: To study the effects of estradiol on the expression of bcl-2 and caspase-3 in cerebral ischemia-reperfusion brain tissue in rats. Methods: Rat cerebral ischemia-reperfusion injury model was established with the middle cerebral artery occlusion by reversible inserting a nylon thread method. The expression and location of bcl-2 and caspase-3 were detected by immunohistochemistry. Results: The expression of bcl-2 in cerebral cortex in estradiol treatment group at 12 h and 24 h were significantly higher compared with sham operation group and ischemia-reperfusion group.The number of bcl-2 positive cells in corpus stratum of the 3 groups had no difference at different time points. In sham operation group, cerebral cortex and corpus striatum did not express caspase-3. The number of caspase-3 positive cells in cerebral cortex of estradiol treatment group decreased at 12 h and 24 h compared with ischemia-reperfusion group. Conclusion: It is demonstrated that pretreatment with estradiol could induce expression of bcl-2 and suppress the activity of caspase-3 in neurons within the cerebral cortex.