延迟相吗啡预处理对兔心肌缺血再灌注损伤的保护作用

Morphine Delayed Preconditioning Against Myocardial Ischemic-Reperfusion Injury in Rabbit

目的探讨延迟相吗啡预处理对兔心肌缺血再灌注损伤的保护机制。方法30只健康新西兰雄性大白兔随机分成3组:假手术组(C组)、缺血再灌注组(I/R组)、吗啡预处理延迟相组(M组),每组10只。C组仅行左冠脉套线而不阻断160 min;I/R组行左冠状动脉前降支阻断40 min,再灌注120 min;M组静注吗啡1.0 mg/kg,24 h后处理同I/R组。各组分别于阻断前20 min(T1)、阻断后20 min(T2)、阻断后40 min(T3)、再灌注1 h(T4)、再灌注2 h(T5)五个时点取颈内动脉血测定血清中白介素(IL)-10和肿瘤坏死因子(TNF)-α含量。再灌注结束后用伊文思蓝和TTC染色法测心梗面积。结果与C组比,I/R组与M组IL-10和TNF-α含量均升高,具有显著性差异(P<0.05),但与I/R组比,M组IL-10明显升高(P<0.05),心肌梗死面积减少(P<0.05),TNF-α明显降低(P<0.05)。结论吗啡预处理延迟相可通过调控炎性细胞因子平衡发挥心肌保护作用。

OBJECTIVE To investigate the protective effects of morphine delayed preconditioning on myocardial ischemia reperfusion injury in rabbit.METHODS Thirty New Zealand male white rabbits were randomly assigned to control group（C group）,ischemia reperfusion group（I/R group） and morphine group（M group）.M group was given morphine 1.0 mg/kg,C group and I/R group were given NS 1.0 ml/kg as untreated controls.Twenty-four hours later I/R group and M group underwent 40 min of coronary occlusion followed by 2 h of reperfusion.Blood samples were taken from arterial line at 20 min before occlusion（T1）,20 min after occlusion（T2）,40 min after occlusion（T3）,1 h after reperfusion（T4） and 2 h after reperfusion（T5） for determination of plasma IL-10 levels and TNF-α levels.At the end of the reperfusion,infarct size（IS） and area at risk（AAR） were defined by Evans and TTC staining.RESULTS Morphine significantly（P〈0.05）reduced infarct size（21.5%±2.4% in M group） of the left ventricular area at risk as compared with control（37.8%±1.7% in I/R group）.M group had a lower levels of TNF-α and a higher level of IL-10 than those in I/R group.CONCLUSION Morphine preconditioning induces late cardioprotection against postischemic reperfusion injury partly by regulating cytokine in rabbit.