The Study Of Relationship Between Calcineurin And NF-κB On Myocardium Ischemia/Reperfusion Of Aging Rat

Objective:To research the relationship between Calcineurin(CaN) and NF-κB on aging rat of acute myocardial ischemia-reperfusion injury. To explore the mechanism of CaN induce myocardial cell apoptosis .Methods :Eighteen rats were randomly divided into three group( n = 6 each): the sham-operation group(sham group), the ischemia-reperfusion group(I/R group) , the drug administration group(CsA group). The CsA group was given CsA 10 mg·kg-1·d-1 through the abdominal cavity injection for 10 consecutive days, Then the myocardial ischemia/reperfusion(I/R) was included in two groups of CsA group and I/R group by ligation of the left anterior descending branch of the coronary artery (LAD) for 30 min and reperfusion for 180 min. The myocardial activity of calcineurin was detected by CaN determination kit. the myocardial expression of NF-κB was detected with Western blotting ,the rate of the cardiomycyte apoptosis was assessed by flow cytometry.Results :1. The aging rat model of acute myocardial ischemia/reperfusion injury are well established.2. After I/R The activity of calcineurin is heighten(1.625±0.684 vs 0.423±0.209, P<0.05) and the protein level of NF-κB is increased(0.953±0.030 vs 0.822±0.037, P<0.05), the rate of myocardial apoptosis is increased(24.70±3.12% vs 3.23±0.97%, P<0.05). After administration, the activity of calcineurin is degraded(0.982±0.295 vs 1.625±0.684, P<0.05) and the protein level of NF-κB is weakened(0.901±0.012 vs 0.953±0.030, P<0.05), the rate of myocardial apoptosis is degraded (12.88±4.08% vs 24.70±3.12%, P<0.05).3. After correlation analysis, the correlation coefficient between the activity of calcineurin and the protein level of NF-κB r=0.861.Conclusion :1. CaN was suggested to own positive effect on the cardiac myocytes apoptosis. The mechanism may be through promote the expression of NF-κB, then activate the pathway of NF-κB. 2. Inhibit the activation of CaN can decrease overexpression of NF-κB which induced by myocardial Ischemia-reperfusion injury, play myocardial cell protection effect.