电针预处理对MCAO大鼠模型血脑屏障和MMP-9的影响

目的:探讨电针(EA)预处理对大鼠脑缺血再灌注后血脑屏障(BBB)通透性及脑内基质金属蛋白酶-9(MMP-9)表达的影响。方法:96只成年雄性SD大鼠随机分为假手术(Sham)组、单纯电针(EA)组、缺血(MCAO)组及电针预处理(EA+MCAO)组,每组24只。使用线栓法制作大鼠大脑中动脉阻塞(MCAO)模型,缺血120 min再灌注48 h后处死取脑。分别采用干湿重法测定各组动物脑水含量,伊文斯蓝(EB)法检测血脑屏障通透性,Western Blot检测紧密连接蛋白(TJP)及MMP-9表达水平,同时明胶酶谱法检测MMP-9活性。结果:与Sham组相比,MCAO组大鼠脑水含量及EB含量增多(P0.05),缺血侧脑组织TJP水平下降(P0.05),MMP-9表达及活性明显升高(P0.05);与MCAO组大鼠比较,EA+MCAO组脑水含量及EB含量减少(P0.05),缺血侧脑组织TJP水平升高(P0.05),同时MMP-9表达及活性显著降低(P0.05)。结论:电针预处理通过抑制缺血后脑内MMP-9的表达及活性,维持BBB完整性,有效改善脑缺血后的脑水肿症状。

Effect of Electroacupuncture Pretreatment on Blood-Brain Barrier and Expression of Matrix Metalloproteinase-9 in a Rat Model of MCAO

Objective:To investigate the effect of electroacupuncture (EA) pretreatment on the permeability of blood-brain barrier (BBB) and expression of matrix metalloproteinase-9 (MMP-9) in rats following cerebral ischemia-reperfusion injury.Methods:Ninety-six adult male SD rats were randomly divided into sham surgery (Sham) group,EA pretreatment (EA) group,middle cerebral artery occlusion (MCAO) group,and MCAO with EA pretreatment (EA + MCAO) group (n =24).Cerebral ischemia-reperfusion model was established using suture method.At 48 h after the reperfusion following 120 min ischemia,brain water content was determined by dry/wet weight method,BBB permeability was measured by Evans blue (EB) staining and the expression of TJP and MMP-9 were evaluated by Western Blot.Meanwhile,the activity of MMP-9 was measured by gelatin zymography.Results:Compared with Sham group,brain water content and EB content were higher (P ＜ 0.05) while the levels of TJPs in the ipsilateral brain were lower (P ＜ 0.05) in the MCAO group.The expression and activity of MMP-9 were higher in the MCAO group than in the Sham group (P ＜ 0.05).Compared with MCAO group,brain water content and EB content were lower in EA + MCAO group (P ＜ 0.05),while the levels of TJPs were higher and the expression and activity of MMP-9 were lower in the EA + MCAO group than in the MCAO group (P ＜ 0.05).Conclusion:Electroacupuncture pretreatment can inhibit the expression and activity of MMP-9,maintain BBB integrity and relieve brain edema after cerebral is chema.