牛磺酸增强渐增再灌注心肌保护作用的实验研究

Taurine's enhancement of myocardial protective effects on gradual reperfusion

目的研究牛磺酸对渐增再灌注处理的离体大鼠缺血/再灌注损伤心肌的保护作用。方法采用Langendorff离体心脏灌流法制备离体大鼠心肌缺血/再灌注模型。SD大鼠随机分为7组:正常对照组(Nor)、缺血/再灌注组(I/R)、渐增再灌注组(GR)、牛磺酸低浓度组(T20)、牛磺酸高浓度组(T40)、渐增再灌注联合牛磺酸低浓度组(GT20)、渐增再灌注联合牛磺酸高浓度组(GT40)。记录平衡末及再灌注90min心功能,TTC染色法测定心肌梗死面积,检测冠脉流出液中乳酸脱氢酶(LDH)活性及心肌组织中Caspase-3活性,TUNEL法检测心肌细胞凋亡。结果与缺血/再灌注组比较,GR、牛磺酸能够改善心功能,减少心肌梗死面积,减少LDH漏出,降低心肌Caspase-3活性并减少心肌细胞凋亡;相比单纯应用GR及牛磺酸,渐增再灌注联合牛磺酸的保护作用更强,且GT40组保护作用最强。结论 GR和牛磺酸均能减轻大鼠离体缺血/再灌注心肌的损伤,牛磺酸,特别是高浓度牛磺酸能够增强渐增再灌注对心肌的保护作用,抗凋亡可能是二者发挥心肌保护作用的机制之一。

Aim To observe taurine＇s enhancement of myocardial protective effects on gradual reperfusion in isolated rat hearts.Methods Isolated myocardial ischemia-reperfusion（I/R） model was replicated by Langendorff perfused rat heart.Sprague-Dawley rats were randomly divided into seven groups： normal group（Nor）,I/R group,gradual reperfusion group（GR）,taurine of lower concentration group（T20）,taurine of higher concentration group（T40）,gradual reperfusion combined with taurine of lower concentration group（GT20） and gradual reperfusion combined with taurine of higher concentration group（GT40）.The cardiac function was recorded.The activity of LDH in coronary effluent and myocardial Caspase-3 were detected.The myocardial infarct size and cardiocyte apoptotic index（AI） were measured with TTC and TUNEL staining method at the end of reperfusion in each group.Results Compared with I/R group,cardiac function was improved significantly,the myocardial infarct size,the activity of LDH and myocardial Caspase-3,and the apoptotic index were reduced remarkably in GR,T20,T40,GT20,GT40.The protective effects of gradual reperfusion combined with taurine on I/R injury were more potent than applying gradual reperfusion or taurine alone,and the protective effects of GT40 were the most obvious.Conclusion Gradual reperfusion and taurine can reduce I/R injury in isolated rat hearts.Anti-apoptosis may be one of the mechanisms of the myocardial protective effects.The myocardial protective effects of gradual reperfusion are enhanced by taurine,especially taurine of higher concentration.