OBJECTIVETo investigate the effects of oxidative stress on ventricular remodeling after acute myocardial infarction (AMI) in rats.

METHODSAMI was induced in 20 SD rats by ligation of the anterior descending coronary artery, and another 12 rats without the ligation served as the sham-operated group. Six weeks after the operation, the heart mass index (HMI), left ventricular mass index (LVMI), right ventricular mass index (RVMI), the indexes of heart function, cardiac myocyte apoptosis index, collagen content and collagen I/III ratio and the indexes of oxidative stress were measured.

RESULTSAfter AMI, HMI, LVMI and RVMI increased significantly (P<0.05), the heart function deteriorated significantly (P<0.01), and the cardiac myocyte apoptosis index in the non-infarct area, collagen content and collagen I/III ratio in the infarct and non-infarct areas were all significantly increased (P<0.05 or 0.01). Myocardial superoxide dismutase (SOD) activity was significantly lowered after AMI, which resulted in significantly increased myocardial malondialdehyde (MDA) level and decreased ratio of SOD/MDA (P<0.05). Correlations were found between the indexes of oxidative stress in myocardium, those of the heart function and those pertaining to ventricular remodeling after AMI.

CONCLUSIONOxidative stress may be involved in ventricular remodeling after AMI, and antioxidants can be an option for treatment of ventricular remodeling.