褪黑激素对大鼠体外供心延时保存效果的作用研究

The cardioprotective effect of melatonin on hypothermic preservation of rat donor heart

目的:探讨褪黑激素对大鼠供心延时保存效果的作用。方法:将 64 只 Wistar大鼠随机分为对照组和实验组。对照组:供心单用St Thomas液4℃保存;实验组:用含褪黑激素(0.1 mmol/L)的St Thomas液4℃保存。分别于保存前及保存6,12,24 h后,取出供心,在改良的非循环式Langendorff Neely灌注模型上测定血流动力学指标。高效液相色谱法测心肌细胞线粒体ATP水平。原位末端标记法(TUNEL)检测细胞凋亡,计算心肌细胞凋亡指数(AI)。电镜观察心肌超微结构。结果:实验组左心功能恢复、心肌超微结构、线粒体 ATP水平等均明显优于对照组(P<0.01)。实验组各时间点心肌细胞 AI明显小于相应对照组(均 P<0.01)。结论:褪黑激素增补于供心保存液中可明显改善体外供心延时保存效果,机制可能与其减少心肌细胞凋亡有关。

Objective:To study the effects of melatonin on hypothermic preservation of rat donor heart. Method:Sixty-four rats were randomly divided into two groups. Experimental group(n=32) ,isolated rat hearts were preserved in 4℃ St Thomas solution with melatonin ( 0.1 mmol/L).Control group(n=32) , isolated rat hearts were preserved in 4℃ St Thomas solution only.Before and after 6,12,24 hours of preservation ,the donor hearts were mounted on modified Langendorff-Neely model. High-performance liquid chromatography was used to measure myocardial ATP level; The hemodynamic parameters, myocardial ultrastructure were measured after 6,12,24 hours of preservation. Apoptosis index (AI)was evalulated by the percentage of myocardial cells with TUNEL positive staining. Result:Recovery of cardial function and myocardial ultrastructure in experimental group was significantly better than that in control group; The content of ATP in experimental group was significantly increased ( P< 0.01). AI of myocardial cell in experimental group were found significantly lower than those of control group(P< 0.01) . Conclusion: Melatonin (0.1 mmol/L) supplement in St Thomas solution could significantly reduce donor myocardial cell apoptosis and improved the preservation effect of rat hearts.