抗坏血酸对麻醉大鼠再灌性心律失常的影响

目的观察抗坏血酸对大鼠再灌注心律失常在体模型影响,并探讨其作用机制。方法将52只雄性SD大鼠（220~250g）随机分为5组：假手术组（n=8）,模型组（n=20）,抗坏血酸25mg/kg组（n=8）,50mg/kg组（n=8）,100mg/kg组（n=8）;通过结扎左冠状动脉前降支的方法建立再灌注心律失常模型,药物处理组于术前10min静脉注射抗坏血酸;分析再灌注期心电图变化及检测缺血心肌丙二醛含量。结果与模型组相比,50、100 mg/kg抗坏血酸显著改善了心律失常评分,缩短室颤时间,减少缺血心肌丙二醛含量。结论高剂量的抗坏血酸能明显减轻再灌注心律失常导致的损害,其作用机制可能与其提高心肌抗氧化能力,保持膜的稳定性和完整性相关。

Effects of Ascorbic Acid on Ischemia-Reperfusion Induced Arrhythmias in Anesthetized Rats

Objective To observe the effects ofascorbic acid on ischemia-reperfusion induced arrhythrnia in vivo and to elucidate the underlying mechanism.Methods Fifty-two male Sprague-Dawley(SD)rats were randomly divided into the following group:sham group(n=8),model group(n=20),and 25mg/kg,50 mg/kg and 100 mg/kg ofascorbic acid treatment group(n=8,respectively).Reperfusion arrhythmia model was established by ligation of the left anterior descending coronary artery.Drugs were administered intravenously 10 min before the surgery in ascorbic acid groups.Electrocardiogramduring the reperfusion phase and content of malondial-dehyde in ischemia-reperfusion myocardium were analyzed.Results Compared with the model group,the mortality,the ventricular arrhythmias scores and the duration ofventricular fibrillation could be significantly decreased,and the malondialdehyde of ischemia-repsrfusion myocardium also could be reduced significantly in ascorbic acid treatment group(50,100 mg/kg).Conclusions Ascorbic acid(50,100 mg/kg)could reduce effectively the ventricular fibrillation induced by ischemia-reperfusion,which might be attributed to enhance anti-oxidative function of the myocardium and to preserve the stability and integrity of the membrane.