L-精氨酸对大鼠肢体缺血／再灌注后心肌损伤的影响

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

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。

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 meth- ods. L-Arg （150 mg · kg^-1） were intravascularly in-jected 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 venteic- ular systolic pressure（ LVSP）, maximal rise rate of left venteicular pressure （ dp/dtmax ） and the maximal fall rate of left venteicular pressure （ - dp/dtmax ） were mo- nitored. Morphologic changes of myocardium were e- valuated after reperfusion. Results After rats＇ limbs suffering from ischemia-reperfusion, levels of MDA, MPO and TNF-ct 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 differ- ences were significant. Under microscope, signs of my- ocardium injury were observed. Myocardium were bet- ter reserved in L-Arg ＋ I/R group. Conclusion L-Arg can protect the myocardium from limb ischemia-reper- fusion and the protective effects may be related to anti- oxidation and inhibition of inflammatory response.