七氟醚预处理对大鼠局灶性脑缺血再灌注时mGluR Ⅱ表达的影响

Effect of sevoflurane preconditioning on expression of metabotropic glutamate receptor type Ⅱ during focal cerebral ischemia-reperfusion in rats

目的 评价七氟醚预处理对大鼠局灶性脑缺血再灌注时代谢型谷氨酸受体Ⅱ( mGluRⅡ)表达的影响.方法 清洁级健康雄性SD大鼠48只,体重250~280 g,采用随机数字表法分为3组(n=16):假手术组(S组)、脑缺血再灌注组(I∕R组)和七氟醚预处理组(Sev组). S组只分离血管不结扎;I∕R组采用大脑中动脉栓塞法制备大鼠局灶性脑缺血再灌注损伤模型,缺血2 h,再灌注24 h;Sev组吸入2. 7%七氟醚1 h,24 h后操作同I∕R组.于再灌注24 h后进行神经功能缺陷评分;TTC染色法确定脑梗死体积;TUNEL染色法观察缺血半暗带细胞凋亡情况,计算细胞凋亡率;Western blot法测定IκB-α的表达水平;免疫荧光染色法检测mGluRⅡ的表达水平.结果 与S组比较,I∕R组和Sev组神经功能缺陷评分、脑梗死体积和细胞凋亡率升高,mGluRⅡ表达上调,IκB-α表达下调( P<0. 05);与I∕R 组比较,Sev组神经功能缺陷评分、脑梗死体积,细胞凋亡率降低,mGluRⅡ表达下调, IκB-α表达上调(P<0. 05).结论 七氟醚预处理通过抑制mGluRⅡ表达减轻大鼠脑缺血再灌注损伤.

Objective To evaluate the effect of sevoflurane preconditioning on the expression of metabotropic glutamate receptor type Ⅱ(mGluR Ⅱ )during focal cerebral ischemia-reperfusion (I/R)in rats.Methods Forty-eight clean-grade healthy male Sprague-Dawley rats were divided into 3groups (n= 16each)using a random number table method:sham operation group (group S),cerebral I/R group (group I/R)and sevoflurane preconditioning group (group Sev).Rats were anesthetized with 10%chloral hydrate 3ml/kg.Focal cerebral I/R was produced by occlusion of the right middle cerebral artery for 2h followed by 24h reperfusion.In group Sev,2.7%sevoflurane was inhaled for 1h and 24h later focal cerebral I/R was produced.At 24h after reperfusion,neurological deficit was scored,the cerebral infarct size was determined by TTC staining,the cell apoptosis in ischemic penumbra was observed by TUNEL,IKB-α expression was detected by Western blot,and mGluR Ⅱ expression was determined by immunofluorescent staining.The apoptosis rate was calculated.Results Compared with group S,the neurological deficit score, cerebral infarct size and apoptosis rate were significantly increased,the expression of mGluR Ⅱ was up-regulated,and the expression of IκB-α was down-regulated in I/R and Sev groups (P<0.05).Compared with group I/R,the neurological deficit score,cerebral infarct size and apoptosis rate were significantly decreased,the expression of mGluR Ⅱ was down-regulated,and the expression of IKB-α was up-regulated in group Sev (P<0.05).Conclusion Sevoflurane preconditioning reduces focal cerebral I/R injury through inhibiting the expression of mGluR Ⅱ in rats.