Effect of ischemic postconditioning on myocardial ischemia/reperfusion injury in hyperlipemia rats

AIM To study the effect of ischemic postconditioning on myocardial ischemia/reperfusion injury in hyperlipemia rats. METHODS Thirty-six hyperlipemia SD rats were selected and randomly divided into 3 groups: sham-operation group, ischemic reperfusion group and ischemic postconditioning group, with 12 rats in each group, and MIR models were established. Rats in the ischemic reperfusion group were ligated for a 40-minute ischemia, and then were reperfused for 240 minutes. Rats in the ischemic postconditioning group were ligated for a 40-minute ischemia, reperfused for 10s and 10s ischemia for three cycles, and then reperfused for 240 minutes. In the sham-operation group, the chests of the rats were opened to braid for ringer without ligation. The activity of creatine kinase, SOD, MDA and myocardial infarct size were measured. RESULTS ①The serum creatine kinase activity was obviously higher in the ischemic postconditioning group and ischemic reperfusion group after reperfusion compared with that in the sham-operation group ［which were respectively（712.94±20.68）, （946.58±27.43） and （232.12±18.26）U/L, P<0.05, 1 U=16.67 nkat］. The serum creatine kinase activity was significantly lower in the ischemic postconditioning group than that in the ischemic reperfusion group (P<0.05). ②The activity of SOD was much higher in the ischemic postconditioning group than that in the ischemic reperfusion group (P<0.05). The activity of MDA was lower in the ischemic postconditioning group than that in the ischemic reperfusion group (P<0.05). ③No significant difference was found in the ratio of myocardial ischemic area and the size of left ventricle after reperfusion in the ischemic postconditioning group and ischemic reperfusion group. The ratio of myocardial necrosis area and the myocardial ischemic area was significantly lower in the ischemic postconditioning group compared with that in the ischemic reperfusion group (P<0.05). CONCLUSION Ischemic postconditioning relieves the ischemic reperfusion injury in hyperlipemia rats.