Effect of blood lipid on myocardial injury in rats with myocardial infarction

AIM: This study investigated the effect of elevated blood lipid levels on myocardial injury in rats with myocardial infarction. MATERIALS AND METHODS: Sprague-Dawley (SD) rats were randomly assigned to six groups (n=9 per group): normal, sham, acute myocardial infarction (AMI), AMI+30% high-fat (HF), AMI+70% HF, AMI+100% HF and AMI+100% HF+PD (atorvastatin treatment). After 3 weeks of dietary intervention or treatment, serum and heart tissue samples were collected. Serum concentrations of triglycerides (TG), total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), lactate dehydrogenase (LDH), creatine kinase-MB (CK-MB) and cardiac troponin I (cTnI) were measured. Myocardial pathologic changes were examined using H&E staining. Cardiomyocyte apoptosis was evaluated using the TUNEL assay, andcaspase-3 and caspase-12 protein expression levels in myocardial tissue were determined using western blot analysis. RESULTS: Compared to the normal group, TG, TC, LDL, LDH, CK-MB and cTnI levels were significantly increased, whereas HDL levels were significantly decreased in the AMI+30% HF, AMI+70% HF and AMI+100% HF groups. These changes were accompanied by a significant increase in cardiomyocyte apoptosis and marked pathological deterioration of myocardial tissue. By contrast, atorvastatin supplementation markedly improved lipid profiles and cardiac function and reduced cardiomyocyte apoptosis. CONCLUSIONS: .