缺血后处理对缺血再灌注大鼠心肌间质的保护作用

Pretection of Ischemic Postconditioning Against Myocardium Ischemia-reperfusion Injury in Rats

目的:探讨缺血后处理对缺血再灌注大鼠心肌间质的保护作用及与心功能的关系。方法:24只SD大鼠随机分为3组,假手术组(SC组)、缺血再灌注组(I/R组)和缺血后处理组(IPTC组)。观察各组心肌羟脯氨酸含量和胶原纤维含量,记录左室血流动力学变化、测定血浆中MDA和SOD浓度改变及观察心肌超微结构变化。结果:IPTC组心肌羟脯氨酸含量、胶原纤维含量、左室舒缩功能明显高于I/R组,心脏超微结构损伤明显减轻。同时,血浆SOD活力增强而MDA含量降低。结论:IPTC对I/R大鼠心肌间质有明显的保护作用,且与心功能的保护相关。其机制可能是通过清除体内自由基、增强机体的抗氧化能力、减少心肌胶原的降解,维持左室结构而起到改善心功能的作用。

Objective：To investigate the protective mechanism of ischemic postconditioning（IPTC）on myocardia ischemic-reperfusion and the affect of oxygen free radicals in the mechanism.Methods：24 rats were randomly divided into 3 groups：sham control（SC）group,ischemic/reperfusion（I/R） group and ischemic postconditioning（IPTC） group.The amount of myocardium hydroxyproline and collagenous fiber proportion were determined;The left ventricular peak systolic pressure and its derivate（±dp/dt） were calculated;The vitality of superoxide dismutase（SOD） and content of malondialdehyde（MDA） of plasma were detected;The microstructure of myocardium was observed by electron microscope.Results：As compared with I/R group,IPTC could increased the content of myocardium hydroxyproline and collagenous fiber proportion,ameliorate left ventricular function,reduce the damage of microstructure.In the meantime,the vitality of superoxide dismutase（SOD） of plasma were greatly enhanced and the content of malondialdehyde（MDA） of plasma were reduced in IPTC group.Conclusion：The beneficial effect of IPTC on myocardium due to obviously protect myocardial interstitium.Its mechanism may be through by scavenging free radicals,strengthening the antioxidant capacity and reducing the degradation of myocardial collagen,and play the role of improving heart function.