Changes of apoptosis of myocardial cells and expression of Bcl-2 and Bax of pigs with myocardial ischemic postconditioning

[Objective] To discuss the changes of apoptosis of myocardial cell and expression of Bcl-2 and Bax of pigs with myocardial ischemic postconditioning.[Methods] 24 Yorkshire pigs either sex weighing 35～40 kg were divided into four groups.Cardiopulmonary bypass(CPB) model of myocardial ischemia-reperfusion was established with Yorkshire pig.Group A: there was no myocardial ischemia;Group B: myocardial ischemic preconditioning was enforced before ACC;Group C: myocardial ischemic postconditioning was executed before reperfusion;Group D: myocardial ischemic preconditioning was enforced before ACC and myocardial ischemic postconditioning was performed before reperfusion.The apoptosis rate,Bcl-2 and Bax in Left ventricular myocardium were detected in every group.[Results] The apoptosis rate in left ventricular myocardium in group B(10.46±0.91%),group C(9.68±0.59%) and group D(11.35±1.37%) was lower than that in group A((19.75)±1.81%) significantly(P0.05).The results of the fluoresce activated cell sorting demonstrated that the expression of Bcl-2 in group B,group C and group D was higher significantly than that in group A,and the expression of Bax in group B,group C and group D was lower than that in group A.There was no significant difference among group B,group C and group D in the above parameters.There was a positive correlation between apoptosis rate and Bax/Bcl-2.[Conclusion] Ischemic postconditioning could lessen ischemic reperfusion injury by reducing the rates of myocyte apoptosis,up-regulating Bcl-2 and down-regulating Bax.