大鼠Langendroff离体心脏局部缺血再灌注模型建立及功能评价

Establishment and assessment of a Langendorff perfused rat heart model of ischemia-reperfusion

目的建立大鼠Langendorff离体心脏局部缺血再灌注模型的方法并进行功能评价。方法将26只Wistar大鼠随机分成2组,对照组(control,n=12)和模型组(model,n=14)。两组均建立标准的Langendorff离体心脏灌注模型:K-H液持续灌注(95%O2+5%CO2过饱和,左心室插入球囊压力管),K-H液持续灌注平衡20min后对照组K-H液持续灌注105 min;模型组同对照组平衡20 min后穿线结扎冠状动脉左前降支第一对角支下缘部位,造成局部停灌(缺血)30 min,而后剪断结扎线复灌(再灌注)75 min。伊文思蓝、TTC染色观察心肌梗死、缺血面积;记录左心室压力及心率变化过程,比较各组平衡20 min、局部缺血30 min、再灌15 min、再灌30 min、再灌75 min的血流动力学指标及灌流液中肌酸激酶(creatine kinase,CK)和乳酸脱氢酶(lactate dehydrogenase,LDH)漏出量。结果对照组血供正常,模型组局部缺血、梗死明显;对照组、模型组平衡末心肌酶学及血流动力学各参数无明显差异(P>0.05),模型组局部缺血、再灌注各个观测时刻心肌酶学及血流动力学参数均与对照组有显著差异(P<0.05),说明模型组经历局部缺血、再灌注损伤,心肌酶漏出明显升高,心脏收缩功能、舒张功能受损,心肌耗氧量升高。结论大鼠Langendorff离体心脏局部缺血灌注模型稳定可靠,掌握制作要点及注意事项后,可顺利快速地成功制备,为心肌局部缺血再灌注损伤的研究提供更接近临床疾病状态的实验途径。

Objective To explore and summarize a Langendorff perfused rat heart model of ischemia-reperfusion. Methods Twenty-six Wistar adult rats were divided into two groups randomly： control group （n = 12） and model group （n = 14）. Each rat underwent open-chest surgery. The hearts were removed and immediately eannulated and effectively perfused in Langendorff apparatus. A fluid-filled latex balloon was inserted via left atrium into the left ventricle for measurement of the left ventricular function. Hearts of the control group received continuous perfusion without ischemia for 105 min. Hearts of the model group received 20 min continuous perfusion for stabilization and then underwent 30 min ischemia by left anterior descending coronary artery （LAD） ligation and 75 min reperfusion. Then Evans blue and TTC staining were used to observe the myocardial infarction area. Compared the levels of perfusate CK and LDH, hemodynamic index, heart rates of the control and model groups at different time points ： end of 20 min continuous perfusion, end of 30 min ischemia, reperfusion 15 min, 30 min and 75 min. Results Hearts of the control group showed normal blood supply, while the model group showed evident local ischemia and infarction. There was no significant difference between the control and model groups in myocardial enzymes and hemodynamic indexes at the end of 20 min continuous perfusion （ P 〈 0. 05 ）. In the rest of the time, the myocardial enzymology and hemodynamic indexes in the model group had significant differences compared with that of the control group （P 〈 0. 05 ）, which indicated local ischemia, reperfusion injury, and increased myocardial enzyme leakage, impairment of the heart systolic and diastolic function, and increase of myocardial oxygen consumption in the hearts. Conclusions Langendorff perfused rat heart models of ischemia-reperfusion is stable and effective. After mastering the surgical skills and keeping above attentions, the model can be established successfully and quickly. This model is more close to clinic conditions, and provides a new experimental approach in research of myocardial ischemia-reperfusion injury.