新西兰大白兔心肌梗死模型的改进与评价

Improvement and Assessment of modified New Zealand Rabbits models of myocardial Infarction

目的改进及评价新西兰大白兔心肌梗死模型的建立方法。方法选用新西兰大白兔60只,雌雄各半,体重1.8~2.6（2.2±0.3）kg,随机分成2组：左冠状动脉前降支结扎组（LAD组,n=30）和回旋支结扎组（LC组,n=30）。采用心电图、超声心动图、血流动力学和组织学检查等多种方法来综合评价两组梗死后心脏结构及功能的改变。结果 LC组建模成功率高于LAD组（P〈0.01）,但LC组存活率低于LAD组（P〈0.05）;术后24 h及术后1周的心电图显示LC组的各导联ST段抬高平均值均高于LAD组（P〈0.05）;超声心动图和血流动力学检查结果显示LAD组心功能无明显下降（P〉0.05）,而LC组心功能指标降低（P〈0.05）;病理结果显示LC组心肌梗死面积大于LAD组（P〈0.01）。结论与结扎左前降支相比,结扎回旋支建立的心肌梗死模型心功能下降更为明显,模型稳定,可作为较理想的心肌梗死模型。

Objective To improve and assess the method of establishing myocardial infarction model in New Zealand rabbits. methods A total of 60 New Zealand rabbits were randomly divided into two groups： the left anterior descending coronary artery was ligated in a LAD group（n=30）; the left circumflex coronary artery was ligated in a LC group（n=30）. Electrocardiogram（ECG）, ultrasound cardiogram（UCG）, hemodynamics and histology procedures were performed to detect the changes of cardiac structure and function after myocardial infarction induced by LAD and LC ligation. Results Success rate of the LC group was significantly higher than that in the LAD group（P〈0.01）, but the survival rate in the LC group was slightly lower than the LAD group（P〈0.05）; ECG within 24 h and 1 week after surgery showed that the average values of ST segment elevation in the LC group were significantly higher than that in the LAD group（P〈0.05）; UCG and hemodynamics results showed cardiac function in the LAD group did not decrease significantly（P〈0.05）. In contrast, cardiac function in the LC group were significantly decreased（P〈0.05）. Histopathologic analysis showed that the area of myocardial infarction in the LC group was significantly larger than that in the LAD group（P〈0.01）. Conclusion The myocardial infarction induced by the left circumflex coronary artery ligation is more consistent than that induced by the left anterior descending coronary artery ligation, suggesting that the former is a more appropriate experimental model for evaluations.