Effects Of Calcineurin-dependent Signal Pathway In Cardiac Myocytes Apoptosis After Myocardial Ischemia-reperfusion On Aged Rats

Objective:To approach the effects of calcineurin signal pathway on the aged rats model of acute myocardial ischemia-reperfusion injury induced myocardium apoptosis.Methods:The cyclosperin A group was given cyclosperin A 10 mg·kg^-1·d^-1 through peritoneal injection for 10 consecutive days,when the sham-operation group and the ischemia- reperfusion(I/R) group were given liquor natrii chloridi isotonicus 3 ml·kg^-1·day^-1 at the same time.Then the myocardial ischemia- reperfusion was induced in two groups of cyclosperin A and I/R by ligation of the left anterior descending branch of the coronary artery(LAD) for 30 min and reperfusion for 180 min.Calcineurin phosphatase activity was detected with CaN detecting kits, P-P38MAPK by Western-Blot and the rate of the cardiomycyte apoptosis was assessed by flow cytometry.Results:(1) Calcineurin phosphatase activity,P-P38MAPK and the rate of myocardial apoptosis after I/R all increased on aged rats.Compared with I/R group,calcineurin phosphatase activity, P-P38MAPK in cyclosperin A group degraded(P<0.05),as well as the myocardial apoptosis rate(P<0.05).(2) The correlation analysis indicated there was a positive correlation between the calcineurin activity and the content of P-P38MAPK on the aged rats model of acute myocardial ischemia-reperfusion injury induced myocardium apoptosis.Conclusion:Cyclosperin A was helpful on ischemia-reperfusion myocardium through diminishing CaN activity.CaN was suggested to own positive effect on the cardiac myocytes apoptosis,and through P38MAPK signal pathway.