Remote Protective Effect of Skeletal Muscle Ischemic Preconditioning on Myocardium During Limb Ischemia-Reperfusion

Objective To investigate the effect of ischemic preconditioning on myocardium in rats which suffer from limb ischemia-reperfusion.Methods 24 Wistar rats were randomly divided into 3 groups:control group(C),ischemia-reperfusion group(I/R)and ischemic preconditioning group(IPC+I/R).The contents of xanthine oxidase(XO),superoxide dismutase(SOD)and malondialdehyde(MDA)in myocardial tissues were determined in different groups.The activities of creatine kinase(CK)and creatine kinase MB isoenzyme(CK-MB)in plasma,the level of myeloperoxidase(MPO)in myocardium and the expression of Bcl-2 and Bax were measured.The morphologic changes of myocardium were observed under the microscope.Results After ischemia-reperfusion of rats' limbs,the level of SOD in myocardium decreased,while the contents of XO and MDA and MPO increased to different degrees(P 0.01 or P 0.05).The values of CK and CK-MB in plasma increased obviously,the expression of Bcl-2 and Bax was stronger,and the ratio of Bcl-2/Bax was lower than those in the control group,all with significant differences.Under the microscope,myocardium injury signs were seen in some areas.However in IPC + I/R group,values of the injury indexes were all decreased,and IPC prevented myocardium from oxidation,inflammation and apoptosis.Conclusion Skeletal muscle ischemic preconditioning can protect the myocardium during limb ischemia-reperfusion,and the protection might be related to anti-oxidation,anti-inflammation and inhibiting apoptosis.