Effect of remote ischemia preconditioning on antioxidant ability after myocardial ischemia/reperfusion injury

Abstract:

Objective：To discuss on the effect of remote ischemia preconditioning（RIPC） on antioxidant ability after myocardial ischemia/reperfusion injury（IRI） in rats. Methods：Totally 50 male SD rats were randomly allocated to 5 groups：control group，femoral control group，femoral group，aorta group and aorta control group. The same RIPC protocol was given and then heart IRI was created. At the end of the experiment，serum and heart tissue was obtained to test anti-/oxidation indexes and myocardial injury marker. Hearts were stained to HE and calculate cardiomyocyte apoptosis index（AI）. Results：There was no significant difference in the mean arterial blood pressure within 5 groups before ischemia（P>0.05）. After ischemia，compared with that of control group，mean arterial blood pressure of the other 4 groups was decreased（P<0.05）. The mean arterial blood pressure of the aorta group was the lowest and the area of myocardial infarction was the largest（P＜0.05）. Compared with that of control group，malondialdehyde（MDA） in the other 4 groups was increased（P<0.05），superoxide dismutase（SOD），lactate dehydrogenase（LDH），creatine kinase MB（CK-MB） and cardiac Troponin Ⅰ（cTnⅠ） were decreased（P<0.05）. The serum MDA in the aorta control group was significantly higher（P<0.05），and the SOD，LDH，CK-MB and cTnI were the lowest（P<0.05），and SOD was decreased（P<0.05）. In the control group，the myocardial cells were closely packed and the stripes were clear. The other 4 groups had disorganized cardiomyocytes，vasodilatation，inflammatory cell infiltration and hemorrhage，and the lesions in the aortic group were the most obvious. The apoptosis index of cardiomyocytes in the femoral artery and aorta groups was not significantly different from that in the control group（P>0.05）. Conclusion：RIPC may act against myocardial IRI thorough decreasing the lipid pero-xidation. However，the increased area of RIPC can not promote the cardioprotection and the antioxidant ability is also declined.