恒定磁场对大鼠心肌缺血/再灌注损伤的影响

Effect of constant magnetic field on myocardial ischemia-reperfusion injury in rats

目的观察恒定磁场干预对大鼠心肌缺血/再灌注(I/R)损伤的影响。方法雄性SD大鼠24只,随机分为4组,每组6只,即假手术组、I/R组、50mT恒定磁场+I/R组及100mT恒定磁场+I/R组。大鼠麻醉开胸,结扎冠状动脉前降支40min,再灌注4h。采用Evan’s蓝和TTC染色法测定心肌梗死范围;用TUNEL法测定大鼠心肌组织细胞的凋亡;采用全自动生化分析仪测定血清肌酸激酶(CK)的水平,采用微粒子化学发光法测定血清肌钙蛋白I(cTnI)的水平。结果50mT及100mT恒定磁场干预组I/R后,心肌梗死面积和细胞凋亡指数均显著小于I/R组(P<0.05)。I/R组大鼠血清CK和cTnI的水平与假手术组比较显著升高(P<0.05);而不同强度的恒定磁场干预+I/R组血清CK和cTnI的水平与I/R组比较显著降低(P<0.05)。结论恒定磁场干预能有效地抑制I/R所致大鼠心肌的损伤。

AIM To investigate the effect of constant magnetic field （CMF） on myocardial ischemia/ reperfusion injury （IRI） in rats. METHODS Twenty-four male Sprague-Dawley rats were randomly divided into four groups, 6 rats each group, sham operation group, IRI group, 50 mT CMF intervention group and 100 mT CMF intervention group. The rats were anesthetized and then underwent 40 min of myocardial ischemia and 4 h of reperfusion. The infarct size was assessed by Evans＇ blue and TTC staining.Cardiomyocyte apoptosis was determined by TUNEL method and the level of serum cardiac troponin I （cTn I） was detected by chemiluminescent enzyme immunoassay. The level of sera creatine kinase （CK） was determined by automatic biochemistry analyzer. RESULTS The ratio of infarct size to area at risk （IS/AAR） and cardiomyocyte apoptosis indexes decreased following intervention with 50 mT or 100 mT CMF, which were significantly smaller than those in IRI group （P 〈 0.05 ）. The levels of serum CK and cTnI in IRI group were significantly higher than those in sham operation group （ P 〈 0. 05 ）, whereas the levels of serum CK and cTnI in 50 mT or 100 mT CMF intervention group were significantly lower than those in IRI group （P 〈 0.05）. CONCLUSION Intervention with CMF protects the heart against IRI.