Preventive effects of N-acetyl cysteine on lipids, lipoproteins and myocardial infarct size in isoproterenol induced myocardial infarcted rats: an in vivo and in vitro study.

The present study evaluated the preventive effects of N-acetyl cysteine in isoproterenol induced myocardial infarcted rats. Rats were pretreated with N-acetyl cysteine (10 mg/kg body weight) daily for a period of 14 days. After pretreatment, rats were injected with isoproterenol (100 mg/kg body weight) at an interval of 24 h for two days to induce myocardial infarction. Isoproterenol induced myocardial infarction was indicated by increased activity of creatine kinase-MB and levels of cardiac troponins in the serum. The weight of heart and the levels of serum and heart cholesterol, triglycerides, free fatty acids were increased in isoproterenol induced myocardial infarcted rats. Isoproterenol also increased the levels of serum low density and very low density lipoprotein cholesterol and decreased high density lipoprotein cholesterol. It enhanced the activity of liver 3-hydroxy-3 methyl glutaryl-Coenzyme-A reductase and the levels of lipid peroxidation products. Pretreatment with N-acetyl cysteine showed significant preventive effects in all the biochemical parameters studied in myocardial infarcted rats. Also, N-acetyl cysteine reduced myocardial infarct size. Histopathological findings of N-acetyl cysteine pretreated myocardial infarcted heart correlated with these biochemical findings. The in vitro study confirmed the strong antioxidant action of N-acetyl cysteine. Thus, the present study revealed that N-acetyl cysteine prevented increased heart weight, accumulation of lipids, altered levels of lipoproteins thereby reducing myocardial infarct size due to its antilipidemic and antioxidant effects in isoproterenol induced myocardial infarcted rats. This study may have a significant impact on myocardial infarction.