L-精氨酸对大鼠肢体缺血/再灌注后心肌损伤的影响

目的研究L-精氨酸(L-Arg)对肢体缺血/再灌注(limb ischemia-reperfusion,LIR)后心肌损伤的影响。方法止血带法复制LIR模型,部分动物在再灌注前经静脉给予L-Arg(150mg.kg-1),观察心肌组织MDA、MPO和TNF-α水平和血浆CK、CK-MB及NO的含量;心脏插管观测平均动脉压(MAP)、左心室收缩压(LVSP)、收缩期左室内压上升最大速率(dp/dtmax)、舒张期左室内压下降最大速率(-dp/dtmax);光镜下进行心肌组织的形态学观察。结果LIR后心肌组织MDA、MPO和TNF-α含量增加(P<0.01或P<0.05),血浆CK、CK-MB及NO水平升高(P<0.01),MAP等血流动力学指标下降,镜下可见心肌细胞水肿等组织损伤的征象。静脉给予L-Arg后,心肌组织MDA、MPO含量的增加和血浆CK、CK-MB及TNF-α的升高受到一定程度抑制(P<0.01或P<0.05),NO水平升高更明显(P<0.01),光镜下心肌组织的形态学表现有所改善。结论L-Arg可能通过抗氧化、抑制炎症反应等途径对肢体缺血/再灌注后的心肌发挥保护效应。

Effect of L-Arg on myocardium in rat which suffered from limb ischemia-reperfusion

Aim To investigate the effect of L-arginine(L-Arg) on myocardium in rat which suffered from limb ischemia-reperfusion.Methods Models of limb ischemia reperfusion were made by tourniquet methods.L-Arg(150 mg·kg-1) were intravascularly injected before reperfusion.Contents of malondialdehyde(MDA),myeloperoxidase(MPO) and tumour necrosis factor(TNF-α) in myocardium were measured.Levels of creatine kinase(CK),creatine kinase MB isoenzyme(CK-MB) and nitric oxide(NO) in plasma were deter-mined.The mean arterial pressure(MAP,left venteicular systolic pressure(LVSP),maximal rise rate of left venteicular pressure(dp/dtmax)and the maximal fall rate of left venteicular pressure(-dp/dtmax)were monitored.Morphologic changes of myocardium were evaluated after reperfusion.Results After rats' limbs suffering from ischemia-reperfusion,levels of MDA,MPO and TNF-α in myocardium,CK,CK-MB and NO in plasma increased differently(P<0.01 or P<0.05).Values of indexes of MAP,LVSP,dp/dtmax and-dp/dtmax decreased obviously.All of these differences were significant.Under microscope,signs of myocardium injury were observed.Myocardium were better reserved in L-Arg+I/R group.Conclusion L-Arg can protect the myocardium from limb ischemia-reperfusion and the protective effects may be related to anti-oxidation and inhibition of inflammatory response.