电子自旋共振检测N-乙酰半胱氨酸对大鼠缺血-再灌注心肌中氧自由基的消除作用  

Scavenging Effect of N-Acetylcysteine on Oxygen Free Radicals Derived from the Isolated Ischemic-Reperfused Rat Myocardium--An Electronic Spin Resonance Study

作　　者：李伟[1] 李颖则[1] 邱兆昆[1] 

机构地区：[1]上海市胸科医院心血管外科,上海200030

出　　处：《复旦学报（医学版）》2005年第3期316-320,共5页Fudan University Journal of Medical Sciences

摘　　要：目的　分析于心肌缺血前全身应用N 乙酰半胱氨酸(NAC)对缺血再灌注(I/R)后不同时刻的离体大鼠心肌组织中氧自由基(OFR)的作用情况及其动态变化,探讨NAC对离体大鼠I/R心肌中OFR的消除作用效果及程度。方法　将实验大鼠分成对照组(Ctrl组)和NAC用药组(NAC组) ,于术前用药(分别为生理盐水和NAC) ,制成Langendorff离体心脏灌注模型。用电子自旋共振(ESR)波谱直接检测心肌中的OFR ,观察两组再灌注后不同时刻的大鼠心肌中,OFR信号在ESR波谱中出现的频度及强度,χ2 检测分析两组大鼠心肌在再灌注后不同时刻的OFR信号检测阳性率的差异显著性。结果　再灌注后的NAC组心肌中,无论从OFR出现的频度还是强度均较Ctrl组有较大改善(降低) ,OFR在再灌注后出现高峰的时机明显延迟,其再灌注后5min和10min的OFR信号检测阳性率较Ctrl组显著降低(P <0 .0 0 2 5 ) ,并以再灌注后5min时最为显著。结论　NAC能明显消除离体大鼠I/R后心肌中的OFR ,加强再灌注后心肌的抗氧化能力,降低OFR对心肌组织的损害程度,对缺血 再灌注心肌起到明显的保护作用。Purpose To investigate the scavenging eff ec t of N-acetylcysteine (NAC) on oxygen free ra-dicals derived from the isol ated ischemic-reperfused rat hearts. Methods Thirteen rats were intraperitoneally administer ed with a dose of 20% NAC (15 mg/100 g body weight) while l9 rats in the control group with corresponding volume of 0.9% sodium chloride solution one hour prior to their hearts mounted on a non-circulating Langendorff perfusion column.One hour later after hypothermic ischemia,the hearts were reperfused with 37?℃ Kre b′s-Henseleit solution.Myocardial specimens that were resected from th e both groups of hearts being reperfused 5,10,15 and 30 minutes,respectively,were tested by means of low temperature electronic spin resonance (ESR) technique,th e unique direct measurement method of oxygen free radicals (OFR).The difference of the positive rate and the density of OFR signals in the two groups of myocard ial ESR spectra in different time points following reperfusion were statistica lly analyzed with χ2-test. Results ESR analysis indicated that the positive rate a nd the density of OFR signal following reperfusion in NAC-treated myocardia w er e significantly lower (P<0.002 5) than those in control group,especially at the time point of 5 minutes following reperfusion. Conclusions NAC has a considerable scavenging effect on OFR derived from the ischemic-reperfused rat myocardium,it may enforce the an tioxidative ability of myo-cardium and attenuate the myocardial damage induced by O FR.The burst of OFR following reperfusion is obviously restrained and delayed by NAC.NAC has an obvious effect on myocardial protection.

关 键 词：电子自旋共振 氧自由基 N-乙酰半胱氨酸 缺血-再灌注损伤 心肌 

分 类 号：R541.4[医药卫生—心血管疾病]