大脑中动脉内促红细胞生成素或联合tPA注射对大鼠脑缺血再灌注的作用及机制  

Effect of intra-arterial infusion of erythropoietin alone or in combination with tissue plasminogen activator on rats following focal cerebral ischemia

作　　者：李锦程[1] 武晓宁[2] 赵海苹[1] 闵连秋[2] 王荣亮[1] 罗玉敏[1] 

机构地区：[1]首都医科大学宣武医院脑血管病研究室北京市老年病医疗研究中心,北京100053 [2]辽宁医学院附属第一医院神经内科,辽宁锦州121001

出　　处：《首都医科大学学报》2015年第5期699-704,共6页Journal of Capital Medical University

基　　金：国家自然科学基金面上项目(81071058;81201028;81271461)~~

摘　　要：目的探讨大脑中动脉内低剂量促红细胞生成素(erythropoietin,EPO)或联合组织纤溶酶原激活剂(tissue plasminogen activator,t PA)注射是否有神经保护作用及对内质网应激通路的影响。方法将60只成年雄性Sprague-Dawley大鼠采用数字表法随机分为5组,假手术(sham)组、大脑中动脉栓塞(middle cerebral artery occlusion,MCAO)模型对照组、EPO组、t PA组及EPO联合t PA组,线栓法制备右侧大脑中动脉缺血2 h/再灌注24 h模型,在缺血2 h/再灌注即刻通过大脑中动脉单独注射EPO(800IU/kg)、t PA(10 mg/kg)以及联合注射EPO(800 IU/kg)及t PA(10 mg/kg)。再灌注24 h后评价神经功能缺损,测定梗死体积,检测C/EBP同源蛋白(C/EBP-homologous protein,CHOP)及磷酸化的真核起始因子(phosphorylated form of eukaryotic initiation factor2α,p-e IF2α)的表达。结果与MCAO模型组相比,EPO、t PA+EPO可以显著减小大鼠脑缺血/再灌注(ischemia/reperfusion,I/R)后的梗死体积,改善神经功能,并显著降低微血管和脑组织中p-e IF2α和CHOP的表达,但单独给予t PA没有作用;与t PA组相比,t PA+EPO可以显著减小梗死体积、改善神经功能,并显著降低微血管和脑组织中p-e IF2α和CHOP的表达。免疫荧光显示,CHOP与末端脱氧核苷酸转移酶介导的缺口末端标记法(terminal deoxynucleotidyl transferase-mediated d UTP nick end labeling,TUNEL)有共定位。结论在再灌注即刻通过大脑中动脉内注射低剂量EPO或者低剂量EPO联合t PA可以减轻脑I/R损伤,可能与EPO抑制内质网应激,从而减少神经细胞凋亡有关。Objective To investigate the effect of intra-arterial infusion of erythropoietin alone or in combination with tissue plasminogen activator on rats following focal cerebral ischemia / reperfusion,and examine whether the effects are dependent on endoplasmic reticulum stress. Methods Sixty male rats were randomly divided into 5 groups： sham operation（ sham）,untreated control rats（ ischemic animals）,erythropoietin（ EPO）-treated（ onset of reperfusion,800IU/kg）,tissue plasminogen activator（ t PA）-treated（ onset of reperfusion,10 mg / kg） and EPO ＋ t PA-treated rats. Middle cerebral artery occlusion（ MCAO） was induced by occluding the right middle cerebral artery. Infarct size,neurological deficits,and the levels of phosphorylated form of eukaryotic initiation factor 2α（ pe IF2α） and C / EBP-homologous protein（ CHOP） were measured at 24 hours after reperfusion. Results Compared with the control animals,EPO alone（ P〈0. 05） or in combination with t PA（ P〈0. 05） significantly decreased infarct volume,lessened defective degree of neurological function,and reduced expression levels of p-e IF2α and CHOP. t PA ＋ EPO（ P〈0. 05） significantly decreased infarct volume,lessened defective degree of neurological function,and reduced expression levels of p-e IF2α and CHOP when compared with the t PA-treated animals. Immunofluorescent staining revealed co-localization of CHOP and terminal deoxynucleotidyl transferase-mediatedd UTP nick end labeling（ TUNEL） in cerebral cortical neurons. Conclusion Based on our data,treatment with EPO or EPO ＋ t PA at the onset of reperfusion by intra-arterial infusion may be considered as a useful candidate to alleviate I / R injury and the potential mechanism underlying the role of EPO in a transient focal cerebral ischemia model in rats may be attributable to suppression of endoplasmic reticulum stress,which preserve neuronal cell viability and attenuate behavioral deficits.

关 键 词：促红细胞生成素 组织纤溶酶原激活剂 e IF-2α C/EBP同源蛋白 

分 类 号：R743.31[医药卫生—神经病学与精神病学]