麻醉大鼠再灌注心律失常模型的改良

Modification of reperfusion arrhythmia model in anaesthetized rats

目的改进和完善大鼠再灌注心律失常在体模型的制作方法。方法将36只雄性Sprague-Dawley大鼠随机分为假手术组(n=8)、模型组(n=20)、胺碘酮组(n=8,3mg·kg^(-1),舌下静脉注射)。麻醉动物后,钝性分离大鼠3、4肋间肌,用自制小拉钩拉开胸腔,"双线法"结扎左冠状动脉前降支,经8min缺血后剪断结扎线,再灌注30min,观察各组死亡率,实验中用PowerLab连续描记心电图,分析再灌注期心电图变化。结果模型组再灌注期100%出现明显室性心律失常,包括心室纤颤、室性心动过速、室性早搏等,恶性心律失常引起的死亡率为55%;胺碘酮可有效控制心律失常,仅发生室性早搏,死亡率为0(P<0.01)。结论改良方法制备的大鼠再灌注心律失常的动物模型的重复性好,成功率高。

AIM To modify the model of reperfusion arrhythmias in anaesthetized rats. METHODS Thirty-six Sprague-Dawley rats were randomized into sham group （n = 8）, model group （n = 20）, and amiodarone group （n = 8）. The intercostal muscle （the third intercostal space） was dissected carefully and retractor was used to widen operating field, then left anterior descending coronary artery was ligated in ＂ reduplicated sutures＂ way, which would be sheared after 8 min, reperfused for 30 min subsequently. Amiodarone （3 mg·kg^-1） was injected intravenously 10 min before ischemia. The mortality was observed and electrocardiography （ECG） was recorded by PowerLab during the experiment. The changes of ECG were analyzed during the reperfusion. RESULTS The arrhythmias in the model group could be observed during reperfusion including vemricular fibrillation, ventricular tachycardia and ventricular premature beats. The mortality induced by the malignant arrhythmias in the model group was 55%. However, only isolated ventricular premature beat was observed in the amiodarone group and the mortality of rats was 0. CONCLUSION The reproducibility is better in the in vivo modified method of reperfusion arrhythmias.