观察肢体缺血后处理对急性脑梗死大鼠血脑屏障的保护效应及其机制的探讨

Research on the effects and mechanisms of limb ischemia postconditioning on acute cerebral ischemia BBB in rats

目的探讨肢体缺血后处理对大鼠急性脑梗死后血脑屏障的保护效应及其机制。方法按实验计划建立大鼠大脑中动脉闭塞(MCAO)模型2 h后,再灌注组和肢体缺血后处理组连续5 d进行肢体缺血后处理。比较脑梗死侧的含水量、伊文思蓝(EB)的含量,应用免疫组化方法检测Eph A2、β-淀粉样蛋白(beta amyloid protein,Aβ)的表达。结果再灌注72 h、5 d右侧脑组织含水量均明显高于同时间肢体缺血后处理组;肢体缺血后处理72 h、5 d组比再灌注组同一时间Eph A2及Aβ的阳性细胞数均较低。结论肢体缺血后处理能减轻大鼠急性脑梗死血脑屏障损伤的作用,脑梗死周围区Eph A2和Aβ表达水平的降低可能为保护血脑屏障的机制。

Objective To explore the effects and mechanism of limb ischemia postconditioning on acute cerebral ischemia bloodbrain barrier permeability（ BBB） in rats. Methods After MCAO 2 hours,reperfusion group and limb ischemic postconditioning group animals underwent limb ischemia postconditioning consisting of 3 cycles with each occlusion or release lasting for 2 min（ 2 /2） of bilateral femoral artery. Water content and EB were measured,Eph A2 and Beta amyloid protein were detected by immunohistochemistry. Results The water content of the right side brain were significantly higher than the limb ischemia postconditioning group after ischemia reperfusion 72 h and 5 d; After MCAO 72 h and 5 d,the level of Eph A2 and Beta amyloid protein in neurons and endothelial cells in the peri-infarct region at the limb ischemia postconditioning group were lower than reperfusion group. Conclusion Limb ischemia postconditioning have protective effect to cerebral ischemic BBB and the mechanisms of action is related to reducing the level of Eph A2 and Beta amyloid protein in neurons and endothelial cells in the penumbra region.