胸腺素β4对大鼠心肌缺血再灌注损伤的保护作用

Role of Thymosin β4 （Tβ4） in the Protection of Myocardial lschemia-reperfusion Injury in Rats

【目的】探讨胸腺素β4（Tβ4）对大鼠实验性心肌缺血再灌注损伤的保护作用。【方法】50只健康清洁雄性SD大鼠制备心肌缺血再灌注模型，随机分为假手术纽、模型组、Tβ4小剂量组（20mg／L）、中剂量组（50mg／L）以及大剂量组（100mg／L）组各10只，观察Tβ4处理前后左心室舒张压（LVEDP）、左心室收缩压（LVESP）以及冠脉流量（CF）的变化情况。【结果】TB4能降低大鼠心肌缺血再灌注后LVEDP的增高，增加再灌注损伤后LVESP和CF（P〈0．05）；Tβ4能增加心肌缺血再灌注后清除氧自由基酶类GSH—PX、SOD的表达，同时降低氧自由基MDA的产生（P〈0．05）。[结论]TS4可以改善缺血再灌注损伤大鼠的心功能，对心肌缺血再灌注损伤具有保护作用，其机制可能与其提高缺血心肌抗氧化能力有关。

[Objective] To investigate the protective effect of thymosin β4 （Tβ4） on myocardial ischemia reperfusion injury in rats. [Methods] Fifty healthy SD rats were used to establish myocardial ischemia reperfusion models. They were randomly divided into sham operation group, model group, small dose of Tβ4（20mg/ L） group, middle dose of Tβ4（50mg/l.） group and high dose group of thymosin β4（100mg/L） group with 10 in each group. The changes of diastolic pressure of left ventrieular（LVEDP）, systolic pressure of left ventricular and coronary flow（CF） were observed before and after Tβ4 treatment. [Results] Tβ4 decreased the LVEDP after myocardial ischemia reperfusion, and increased LVP and CF after rcperfusion injury（ P 〈0.05）. Moreover, Tβ4 increased the expression of GSH-PX and SOD, and decreased the production of MDA after my ocardial ischemla reperfusion（ P 〈0.05）. [Conclusion] Tβ4 can improve the cardiac function of isehemia reperfusion injury rats and protect the injury of myocardial ischemia reperfusion. Its mechanism may be related to its antioxidant ability to improve ischemic myocardium.