Effect of ischemic postconditioning on expression of Bcl-2,Bax protein in hyperlipemia rats with ischemic reperfusion

Objective To study the effect of ischemic postconditioning on expression of Bcl-2 and Bax protein in hyperlipemia rats with myocardial ischemia reperfusion.Methods 36 hyperlipemia SD rats were selected and randomly divided into 3 groups:sham operation,ischemic reperfusion and ischemic postconditioning groups(n=12),and rats were made into MIR models.Rats in the ischemic reperfusion group were ligated for 40 minutes ischemia,and then reperfused for 240 min.Rats in ischemic postconditioning group were treated for 40 minutes ischemia,reperfused for 10 s and 10 s ischemia for 3 cycles,and then reperfused reperfussed for 240 min.Rats in sham operation group were opened the chest to braid for ringer without deligation.The presence of apoptotic myocytes was detected by(TUNEL). Immunohistochemistry was used to detect the Bcl-2 and Bax protein.Meanwhile,the serum creatine kinase(CK) activity was measured.Results ① Determination of serum CK activity:it was obviously higher in the ischemic postconditioning group and ischemic reperfusion group after reperfusion than that of the sham operation group(789.68±67.34),(932.86±84.17),(252.48±19.78)U/L respectively,P0.05,and it was significantly lower in the ischemic postconditioning group than that in the ischemic reperfusion group(P0.05).② Number of apoptotic myocardial cells:there was no significant apoptosis found after the reperfusion in the sham-operation group(5%),and the apoptotic rate in the ischemic postconditioning group was remarkably lower than that in the ischemic reperfusion group (11.9±2.7)%,(21.2±3.5)% respectively,P0.05.③ The expression of Bcl-2 protein was higher in the ischemic postconditioning group than that in the ischemic reperfusion group (P0.05).The expression of Bax protein was lower in the ischemic postconditioning group than that in the ischemic reperfusion group (P0.05).Conclusions Ischemic postconditioning may increase the expression of Bcl-2 protein and decrease the expression of Bax protein which may be related with the decreased myocardial apoptosis.