氙气预处理对心肌缺血再灌注损伤大鼠心肌细胞保护作用研究

Protective effect of hernia preconditioning on myocardial cells in rats with myocardial ischemia reperfusion injury

目的:通过观察氙气预处理对心肌缺血再灌注损伤(MIRI)大鼠心肌梗死范围、心肌细胞凋亡指数、心肌组织酶类及氧化应激反应水平的影响,探讨氙气预处理对MIRI大鼠心肌细胞的保护作用及机制。方法:随机抽签方式将64只雄性SD大鼠均分为四组。假手术组(S组)仅做穿线但不结扎;MIRI组(模型组)阻断左冠状动脉前降支,使大鼠缺血30min,恢复灌注120min;0.5MAC疝气预处理+心肌I/R组(0.5XR组)和1MAC疝气预处理+心肌I/R组(1XR组)分别采用0.5MAC氙气和1 MAC氙气预处理大鼠心脏后,缺血30min,恢复灌注120min。灌注120min后,测定各组大鼠心肌梗死范围、心肌细胞凋亡指数、丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-PX)含量及血清中血清肌酸激酶(CK)、肌酸激酶同工酶(CKMB)、一氧化氮合酶(eNOS)活性。结果:与S组相比,模型组心肌梗死范围明显增大,心肌细胞凋亡指数显著升高,心肌组织中SOD、GSH-PX和血清eNOS活性显著下降,MDA含量显著增加,血清CK、CK-MB活性显著增强(P<0.01);与模型组比,0.5XR组和1XR组大鼠心肌梗死范围显著缩小,心肌细胞凋亡指数显著下降,心肌组织中SOD、GSH-PX和血清eNOS活性显著增强,MDA含量显著下降,血清CK、CK-MB活性显著减小(P<0.05)。但0.5XR组和1XR组大鼠上述各指标间比较差异无统计学意义(P>0.05)。结论:氙气预处理对MIRI大鼠心肌组织及细胞具有保护作用,其作用机制可能与抑制机体心肌组织氧化应激反应有关。

Objective:To observe the effects of hernia preconditioning on myocardial infarction size,myocardial apoptosis index,myocardial enzymes and oxidative stress in rats with myocardial ischemia-reperfusion(MIRI)injury,and to investigate the effects of hernia preconditioning on MIRI-induced rat myocardium and the mechanism.Methods:64male Sprague-Dawley rats were divided into4groups by random sampling.The sham operation group(S group)only threaded but did not ligature;the MIRI group(model group)blocked the left anterior descending coronary artery,and the rats were ischemia for30min,and the perfusion was restored for 120min;0.5XR group and1XR group were pretreated with0.5MAC helium and1MAC helium,respectively,and ischemia was30min,and perfusion was continued for 120min.After 120min of perfusion,the myocardial infarct size,cardiomyocyte apoptosis index,MDA,SOD,GSH-PXcontent and serum CK,CK-MB and eNOS activities were measured.Results:Compared with the S group,the myocardial infarction range of the model group was significantly increased,the apoptotic index of cardiomyocytes was significantly increased,the activity of SOD,GSH-PXand serum eNOS in myocardial tissue was significantly decreased,the content of MDA was significantly increased,and the activity of serum CK and CK-MB were significantly increased(P<0.01).Compared with the model group,the myocardial infarction range of the0.5XR group and the1XR group was significantly reduced,the apoptotic index of myocardial cells was significantly decreased,the activities of SOD,GSH-PX and serum eNOS were significantly increased,and the content of MDA was significantly decreased,the activity of serum CK,CK-MB was significantly reduced(P<0.05).However,there was no significant difference between the above indexes in0.5XR group and1XR group(P>0.05).Conclusion:Helium preconditioning has protective effects on myocardial tissue and cells in rats with MIRI injury,and its mechanism may be related to inhibition of oxidative stress in myocardial tissue.