Cell Apoptosis,Caspase3 Expression,and Left Ventricular Segmental Function After Reperfusion in Experimental Acute Myocardial Ischemia

Objective To investigate left ventricular segmental function and alteration of myocardial apoptosis and caspase 3 following acute ischemia reperfusion in dogs. MethodsThirty dogs were divided into ischemia (n=10),reperfusion (n=10),and sham operation as control (n=10) groups. Left anterior descending coronary artery (LAD) were ligated for 30 min while ligation was followed by reperfusion for 120 min in reperfusion group. The left ventricular segmental function were detected by echocardiography using strain rate analysis software. The apoptotic index (AI) in ischemia myocardium was detected by TUNEL,Caspase 3 by immunohistochemistry analysis. Results The peak strain rate (SR_ peak ) in middle segment of left ventricle in ischemia group was decreased obviously ( -0.54 ±0.23)(P0.01),with postsystolic compression (PSC). SR_ peak increased slightly after reperfusion 120 min(-0.89±0.43),but still lower than control group. No difference in positive rate of TUNEL in ischemia myocardium between ischemia group and control groups(2.9±1.3 vs control 2.7±1.7)(P0.05),but it was increased significantly in reperfusion groups(25.1±3.3)(P0.01). Caspase 3 expression was increased in ischemia group and reperfusion group than control group(ischemia 20.0±3.1 vs control 4.7±2.4)(P0.01). Conclusion Caspase 3 expression and cell apoptosis maybe the early changes following acute ischemia reperfusion in dogs,which are related to the left ventricular segmental performance.