不同浓度硝酸甘油对大鼠离体心脏缺血/再灌注损伤的作用

The role of different concentrations of nitroglycerin on cardiac ischemia and reperfusion injury in isolated perfused rat hearts

目的：探讨不同浓度硝酸甘油（nitroglycerin,GTN）对大鼠离体心脏缺血/再灌注损伤的作用。方法：采用离体大鼠心脏Langendorff灌流方法,结扎冠状动脉左前降支30 min和再灌注120 min复制局部缺血/再灌注损伤模型,测定各项心室动力学指标、冠状动脉流出液中乳酸脱氢酶（lactatede hydrogenase,LDH）含量及心肌梗死面积。结果：与单纯缺血/再灌注组相比,GTN高浓度组（2×10-6mol/L）抑制了再灌注后心功能的恢复（P〈0.05~P〈0.01）,增大了心肌梗死面积（P〈0.01）,再灌注时冠状动脉流出液中LDH释放增加（P〈0.05）;GTN中浓度组（1×10-7mol/L）与单纯缺血/再灌注组相比,对心功能的恢复、心肌梗死面积和LDH含量改变不明显;GTN低浓度组（1×10-8mol/L）明显促进了再灌注后心功能的恢复,减小了心肌梗死面积,冠状动脉流出液中LDH释放减少（P〈0.05~P〈0.01）。结论：高浓度GTN加重心肌缺血/再灌注损伤,中浓度GTN对缺血/再灌注心肌作用不明显,低浓度GTN可保护缺血/再灌注心肌。

Objective：To examine the effects of different concentrations of nitroglycerin（GTN） on cardiac ischemia and reperfusion injury in isolated perfused rat hearts.Methods：Male Sprague-Dawley rats were used for Langendoff isolated heart perfusion.The hearts were subjected to 30 min regional ischemia（occlusion of left anterior descending artery） and 120 min reperfusion.The ventricular hemodynamic parameters,lactate dehydrogenase（LDH） release during reperfusion and myocardial infarct size were measured.Results：Administration of GTN at high concentration（2×10-6 mol/L） significantly aggravated post-ischemic myocardial injury characterized by depressed cardiac function recovery（P0.05-P0.01）,enlarged myocardial infarct size（P0.01） and increased LDH release（P0.05）.GTN at middle concentration（1×10-7 mol/L） did not change the cardiac function recovery,myocardial infarct size and LDH release（P0.01）.GTN at low concentration（1×10-8 mol/L） further improved the cardiac function recovery,reduced infarct size and LDH release（P0.05-P0.01）.Conclusions：GTN at high concentration can aggravate cardiac ischemia and reperfusion injury,GTN at middle concentration do not influence heart while GTN at low concentration can protect heart.