Effect of fish oil pretreatment on isoproterenol-induced changes in myocardial membrane phospholipids

Objective: In the present study, the protective effect of fish oil treatment on the fatty acid composition in isoproterenol (IPH)-induced myocardial infarction was studied in male albino Wistar rats. Methods: Rats were injected for 2 consecutive days with IPH (60 mg/kg body weight) at 24-h intervals to induce myocardial infarction. Fish oil was administered orally at a dose of 0.05 mL/d for 45 d, after which serum and heart tissue were assayed for lipid profile, lipoprotein changes, and myocardial membrane phospholipid fatty acid composition. Results: Biochemical assessment of myocardial infarction was done by measuring the activities of creatinine kinase and lactate dehydrogenase, which were significantly elevated in the rats administered with IPH. Further, the administration of IPH modified the fatty acid composition and analysis of fatty acids showed there was an increase in the omega-3/omega-6 ratio in phospholipid pool. In addition, increased levels of total cholesterol, free cholesterol, ester cholesterol, phospholipids, triacylglycerols and free fatty acid was observed in serum and heart tissue of IPH-induced rats. The fish oil treatment for a period of 45 d decreased the levels of cardiac markers (creatinine kinase and lactate dehydrogenase) and reversed the biochemical lesions induced by IPH. Conclusion: Our study suggests that fish oil treatment has a hypolipidemic effect and has potential use in the treatment of myocardial infarction. (C) 2006 Elsevier Inc. All rights reserved.