精胺减轻大鼠在体心肌缺血/再灌注损伤的作用及机制初探

Effects of spermine on myocardial ischemia/ reperfusion injury in rats

目的:观察低浓度外源性精胺对大鼠心肌缺血/再灌注损伤的影响。方法:Wistar大鼠随机分成假手术(Sham)组、缺血/再灌注损伤(I/R)组、盐水对照(NS)组和精胺干预(Sp)组(n=10)。结扎冠脉复制心肌缺血/再灌注损伤模型。Sp组缓慢静脉推注0.5mmol/L精胺2mL/kg。观察指标:心电图,心功能参数,血清SOD、LDH、NO、MDA水平和心肌超微结构等。结果:I/R组心律失常发生率高达90%,心肌超微结构损伤严重,LVSP和±dp/dtmax明显降低,血清中NO、MDA及LDH升高,SOD活性降低(P<0.05或P<0.01vsSham组)。Sp组与I/R组及NS组相比,上述指标均有显著差异(P<0.05或P<0.01)。结论:低浓度外源性精胺能减轻大鼠心肌缺血/再灌注损伤,其机制可能与抗氧化和减轻氧自由基损伤有关。

AIM： To observe the effect of exogenous spermine （low concentration） on myocardial ischemia/ reperfusion injury in rats. METHODS： 40 Wistar rats were randomly divided into 4 groups： sham - operation group （Sham）, ischemic reperfusion group （I/R）, spermine group （Sp） and natural saline group （NS）. The model of ischemic/reperfusion injury was established by ligating rat coronary artery. In Sp group, spermine （0.5 mmol/L, 2 mL/kg） was injected slowly into rat vein. During the process, we recorded the electrocardiogram and the LV functional parameters, assayed the levels of SOD, LDH, NO and MDA in serum, and examined the ultrastructure of the myocardium. RESULTS： In I/R group, the incidence of arrhythmia was 90%, myocardial ultrastructure was injured seriously, values of LVSP and ± dp/dtmax decreased, levels of LDH, NO and MDA increased while SOD activity decreased （ P 〈 0. 05 or P 〈 0. 01, compared with Sham group）. Compared with I/R and NS group, all those indexes in Sp group changed significantly （ P 〈 0.05 or P 〈 0.01 ）. CONCLUSION ： Exogenous spermine alleviates myocardial ischemia/reperfusion injury in rats. The mechanism may be related to its antioxidant effect and relieving the injury caused by oxygen free radical.