Effect of intervention time on apoptosis of myocardial cells in short-term ischemia and reperfusion in rabbits.

Objective:To discuss the effects of myocardial cell apoptosis and expressions of Bcl-2 and Bax protein of different in-terfere time of ischemic postconditioning(Post) during ischemia/reperfusion period on myocardial cell in rabbits.Methods:The experi-ment was finished in the Central Laboratory of Medical College,Shihezi University,from June 2008 to June 2010.36 New Zealand rab-bits were randomly divided into 6 groups(n = 6);sham operation group(Group S),ischemia /reperfusion group(Group IR),ischemic postconditioning group(Group Post1-4).In addition to group S,the other five groups were accepted 30 minutes of reperfusion following 15 minutes of left anterior descending coronary artery occlusion.Group post1-4 were treated respectively with ischemia postconditioning after 3 continuous cycles of ischemia /reperfusion by 10s,15s,30s and 45s.Cardiomyocyte apoptosis were determined by in situ TDT-mediated dUTP nick end labeling(TUNEL).The expression of Bcl-2 and Bax proteins in apoptotic myocardiac cells were detected by immunohistochemistry.Results:Compared with Group IR,Apoptotic Index was significantly lower in Group Post1-4(P0.01).Bcl-2 expression in Group Post1-4 was higher than in Group IR,while Bax expression in Group Post1-4 was lower than in Group IR.Postcon-ditioning Post3 group and Post1,Post2,and Post4 group was statistically significant compared each other(P 0.05),while Post1,Post2,Post4 group was no statistical difference.Conclusion:The duration of transient ischemia /reperfusion of 10s,15s,30s and 45s may reduce myocardial ischemia/reperfusion injury,and 30s is the best intervention time of short-lived ischemia /reperfusion in rabbits.