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目的探讨不同缺血时间和再灌注时间对大鼠离体心脏缺血/再灌注损伤的影响。方法采用Langendorff离体心脏灌流模型,将雄性SD大鼠离体心脏随机分成4组:正常对照组(normal,n=6)、缺血20 min组(I20,n=7)、缺血30 min组(I30,n=8)、缺血40 min组(I40,n=8),观察不同缺血时间组缺血前和再灌注120 min期间冠脉流量、冠脉流出液中肌酸激酶和乳酸脱氢酶的活力及心功能参数的变化,并用2,3,5-三苯基氯化四氮唑(2,3,5-triphenyltetrazolium chlorid,TTC)染色法计算心肌梗死面积。结果与正常对照组相比,I20组、I30组、I40组的冠脉流量、心率、左室发展压及最大上升/下降速率均有所降低(P<0.01,P<0.05),且随再灌注时间的延长而有不同程度的减轻,其中I30组的心肌梗死面积随再灌注时间的延长而逐渐增大,但组内上述指标再灌注30、60、120 min相比均未见统计学差异。各缺血组的心肌酶在再灌注初期明显升高(P<0.01),均在再灌注20 min时达到峰值。且此模型受缺血时间影响较大,I20组造成的损伤较为轻微,而I40组造成的损伤较为严重。结论制备Langendorff大鼠离体心脏缺血/再灌注损伤模型建议以缺血30 min,再灌注30~60 min为宜。
Objective To investigate the effects of different ischemic time and reperfusion time on ischemia / reperfusion injury in isolated rat hearts. Methods The isolated heart of male Sprague-Dawley rats were randomly divided into 4 groups: normal control group (n = 6), ischemia-20 min group (I20, n = 7) (I30, n = 8), 40 min ischemia group (I40, n = 8). The changes of coronary flow and coronary flow in the different ischemic time before and 120 min reperfusion were observed. Lactate dehydrogenase (LDH) activity and cardiac function parameters, and calculate the area of myocardial infarction with 2,3,5-triphenyltetrazolium chlorid (TTC) staining. Results Compared with the normal control group, the coronary flow rate, heart rate, left ventricular ejection fraction and maximum rate of ascending / descending in I20 group, I30 group and I40 group decreased (P <0.01, P <0.05) The perfusion time prolonged with varying degrees of reduction. The area of myocardial infarction in I30 group increased gradually with the reperfusion time, but there was no significant difference between the above groups . The myocardial enzymes in each ischemic group were significantly increased at the beginning of reperfusion (P <0.01), all of which peaked at 20 min after reperfusion. And this model is greatly affected by the ischemic time, the damage caused by I20 group is minor, but the damage caused by I40 group is more serious. Conclusion The model of ischemia / reperfusion injury in isolated Langendorff rats is suggested to be ischemia 30 min and reperfusion 30-60 min.