依达拉奉药物后处理与缺血后处理对急性缺血再灌注心肌保护作用的对比实验研究

Comparive Study of Cardio-Protective Effect on Edaravone Pharmacological Postconditioning and Ischemic Mechanical Postconditioning for Acute Ischemia Reperfusion Injury

目的:探讨新型自由基清除剂依达拉奉的药物后处理是否对急性心肌缺血再灌注损伤有保护作用,与缺血后处理对比,并分析其可能机制。方法:建立大鼠急性心肌缺血再灌注模型。40只大鼠随机分为5组(每组8只):①假手术组;②缺血再灌注组;③缺血后处理组;④依达拉奉主动脉根部注射组(依达拉奉1组);⑤依达拉奉股静脉注射组(依达拉奉2组)。进行心电及血流动力学监测,测定血清肌酸激酶MB同工酶(CK-MB)、丙二醛(MDA)活性及超氧化物歧化酶(SOD)活力,采用伊文思蓝-TTC染色确定梗死及缺血的心肌范围。采用Westernblot印迹检测心肌组织中Bax和Bcl-2蛋白的表达。结果:与缺血再灌注组相比,缺血后处理组、依达拉奉1组和依达拉奉2组的心肌梗死面积显著减少,CK-MB、MDA的水平显著降低,SOD活力增加(P<0.05～0.01),差异均有统计学意义。上述指标缺血后处理组、依达拉奉1组和依达拉奉2组组间比较差异无统计学意义(P>0.05)。缺血后处理组、依达拉奉1组心肌组织Bcl-2蛋白表达分别是缺血再灌注组的1.8倍和1.7倍,Bax蛋白的表达分别是缺血再灌注组的0.52倍和0.54倍(P均<0.05),差异均有统计学意义。结论:对于急性缺血的心肌,在再灌注前注射依达拉奉进行药物后处理可减轻心肌缺血再灌注损伤,保护强度与机械性缺血后处理接近,有效清除氧自由基、提高机体抗氧化应激的能力以及降低凋亡指数(Bax/Bcl-2)是二者的共同机制;主动脉根部—冠状动脉注射途径给药的保护效果不差于静脉注射途径,可能是一种临床上适宜的药物后处理方式。

Objective： In contrast with ischemic postconditioning, to explore the influence of a new free radical scavenger, edaravone pharmacological postconditioning on the myocardial ischemia/reperfusion injury in a rat model, and to investigate the underlying mechanisms, Methods：Experimental model was established by occluding coronary artery with PTCA balloon. Male Wistar rats were ran- domly divided into five groups：①sham operation; ②ischemia/reperfusion （I/R） ;③myocardial ischemic posteonditioning（ Post- C） ; ④edaravone 10 mg/kg, injection of intra aorta root 1 minute before reperfusion （iA） ; ⑤edaravone 10 mg/kg, injection of intra femoral vein 1 minute before reperfusion （iV）. ECG changes and dynamic parameters were monitored during the procedure, and serum biomarkers CK-MB, MDA, SOD were assessed at the end of reperfusion. Ischemic and infarct areas were measured by Evans blue and tetrazolium chloride staining. The expression of Bax and Bcl-2 were analyzed by Western blot analysis. Results： Myocardial infarct size and levels of serum CK-MB, MDA were all significantly reduced in Post-C group and iA group compared with I/R group（ P 〈 0. 01, respectively） , and the activity of SOD was enhanced（ P 〈 0. 05 ）. There were no statistical differences in the foregoing indexes among Post-C group, iA group and iV group（ P 〉 0. 05 ）. Decreased Bax and increased Bcl-2 expression were observed in Post-C group and edaravone group compared with I/R group （ P 〈 0.05 ）, but no statistical differences between Post-C group and edaravone group（ P 〉0.05 ）. Conclusion： Edaravone pharmacological postconditioing applied just before the onset of reperfusion could abate the ischemia/ reperfusion injury, which was similar to the cardio protective effect of mechanical postconditioning. The common mechanism might be associated with decreasing the free radical of oxygen, strengthening the resistance to oxidation stress and down-regulating the apoptotic index（Bax/Bcl-2）. Intra aorta root-coronary injection was similar to intra vein injection, it might be a suitable pharmacological postconditioing pathway in clinical practice.