应用压力-容积环评价硫化氢后适应对心肌缺血再灌注损伤的作用

Evaluation of the effect of hydrogen sulfide postconditioning by P-V loop against myocardial I/R injury

目的探讨应用压力-容积环评价硫化氢(H2S)后适应对大鼠心肌缺血再灌注损伤的保护作用。方法采用结扎左冠状动脉前降支30 min,再灌120 min的方法制备大鼠在体心肌缺血-再灌注损伤模型。Wistar大鼠(n=32)随机分为4组(n=8):假手术组,缺血再灌注组(I/R),缺血后适应组(IPO)和H2S后适应组。假手术组为只穿线,不结扎;I/R组为缺血30 min,再灌120 min;缺血后适应组再灌注之前给予30 s再灌注和30 s缺血,重复3次循环;H2S后适应组,再灌注之前给予H2S供体硫氢化钠静脉注射(15μmol/kg)。记录心率、再灌注室性心律失常、左室收缩末期压(LVESP)及收缩末压力容积关系曲线(ESPVR slope)、左室舒张末期压(LVEDP)及舒张末压力容积关系曲线(EDPVR slope)等心功能参数。应用伊文氏蓝和TTC染色测定心肌梗死面积(%)。结果与I/R组与IPO组比较,硫化氢后适应降低了再灌注室性心律失常的发生率与持续时间,使心律失常评分降低(P<0.05),心肌梗死面积降低(P<0.05);与I/R组相比,压力容积环分析示心功能参数改善(P<0.01),与IPO组比较无明显差别。结论 H2S后适应能够减轻大鼠心肌缺血再灌注损伤,压力容积环能准确敏感地评价心功能。

Objective To evaluate the effect of hydrogen sulfide （H2S） postconditioning on myocardial ischemia-reperfusion （I/R） by pressure-volume loop （P-V loop）. Methods The I/R model of rat in vivo was established by ligating the left anterior descending coronary artery for 30 min and reperfusing for 120 min. Wistar rats （ n = 32） were randomly divided into 4 groups ： sham operation, ischemia-reperfusion （ I/R）, ischemic postconditioning （IPO） and H2S posteonditioning. In sham operation, there was no ligation. In I/R group, the rats were suffered for 30 min of ischemia followed by 120 min of reperfusion. In IPO, three cycles of 30 s reperfusion and 30 s LAD reocclusion were administrated before reperfusion. In H2S postconditioning, NariS （15 μmol/kg, sodium hydrosulfide） was administrated before coronary artery reperfusion. The heart rate （HR）, I/R arrhythmia, the left ventricular end-systolic oressure （LVESP） , left ventricular end-diastolic pressure （LVEDP） , the slope of the end-systolic P-V relation （ESPVR） and the slope of the end-diastolic P-V relation （EDPVR） were detected. Infarct size was determined by scanning the images of the rat heart ventrieular sections stained with Evans blue and TTC. Results Compared with I/R and IPO group, I/R arrhythmia and infarct size were decreased significantly （P 〈0.05）. The parameters of heart function evaluated by P-V loop were improved greatly （P 〈0.01 ） in H2S postconditioning group compared with that in I/R group, but there was no significant difference between H2S posteonditioning and IPO group. Conclusion Myocardial I/R injury can be decreased by H2S postconditioning, and it is sensitive and accurate to evaluate the heari function by P-V loop.