含血停搏液对未成熟心肌缺血-再灌注损伤的实验研究

目的观察冷血浆停搏液对未成熟心肌缺血-再灌注损伤的保护作用。方法选择14～26日龄日本大耳白兔20只,建立Langendorff离体心脏灌注模型。随机抽取4只作为正常对照组(C组),其余16只随机均分为冷血浆组(P组)和冷血组(B组)。C组灌注10minK-H液终止灌注,取右室心肌做检测用。P组、B组降温同时开始分别灌注冷血浆停搏液和冷血停搏液(4℃)15mL/kg,低温(10℃)停搏30min开始复温,再灌注37℃K-H液10min后,采集、处理和保存右室心肌标本。TUNEL法测定心肌细胞凋亡。RT-PCR检测Bcl-2mRNA,行半定量分析。结果C组心肌组织凋亡率为0,P组和B组均出现心肌细胞凋亡,P组凋亡率低于B组(P<0.05)。缺血-再灌注损伤可以使心肌组织中Bcl-2mRNA表达减弱,B组Bcl-2mRNA表达减弱更为明显,P组、B组分别与对照组比较,有显著性差异(P<0.05,P<0.01)。结论未成熟心肌缺血-再灌注伴有细胞凋亡。冷血停搏液、冷血浆停搏液对未成熟心肌缺血均具有保护作用,而冷血浆停搏液作用更为明显。

Effects of cold plasma cardioplegia on immature myocardium during myocardial ischemia reperfusion injury

Objective To determine the effect of plasma cardioplegia on immature myocardium during myocardial ischemia reperfusion injury.Methods Langendorff model for isolated hearts was employed in 20 neonatal rabbits(14～26 d).The rabbits were randomly divided into 3 groups:control group(n=4),cold plasma cardioplegia group(P group,n=8) and cold blood cardioplegia group(B group,n=8).Control group were perfused aerobically(37 ℃) with Krebs-Henseleit perfusate for 10 min in the Langendorff model.Rabbits in P group and B group were perfused with cold plasma cardioplegia and cold blood cardioplegia(4 ℃,15 mL/kg) respectively.After 30 min of sustained ischemia without any perfusion and 10 min of reperfusion with Krebs-Henseleit solution at 37 ℃,the sample of right ventricular myocardium were collected.Myocardial apoptosis and Bcl-2 mRNA were detected by TUNEL and RT-PCR respectively.Results There was no apoptosis in control group,while another 2 groups had apoptosis.Apoptosis index(AI) in P group was lower than that of B group(P<0.05).The Bcl-2 mRNA in P group and B group reduced,especially in B group.Conclusion Immature myocardial ischemia reperfusion injury accompany with apoptosis.Both cold plasma cardioplegia and cold blood cardioplegia have protective effects on isolated model of cardiac arrest,and the effect of cold plasma cardioplegia is more significant.