Abstract: Objectives to investigate the effects of Alpha-linolenic acid (ALA) intake on myocardial ischemia/reperfusion (MI/R) injury in diabetic rats. Methods The high-fat diet-fed streptozotocin (HFD-STZ) rat model was developed. Age-mathched normal and HFD-STZ rats were randomly assigned to receive non-ALA diet or ALA (o.g., 500 μg/kg per day). After 4 wks of feeding animals were subjected to 30 min of myocardial ischemia and 4 or 6 hrs of reperfusion. Results HFD-STZ rats showed more severe myocardial injury. Although ALA intake for 4 wks did not change myocardial injury in normal rats, it significantly reduced infarct size, plasma creatine kinase and lactate dehydrogenase activities, and apotosis in HFD-STZ diabetic rats. Moreover, myocardial PI3K expression and Akt phosphorylation were increased by ALA intake in diabetic but not normal rats. Conclusion Chronic ALA intake confers cardioprotection in MI/R in diabetic but not normal rats, which is possibly through PI3K-Akt-dependent mechanism.

Key words: Alpha-linolenic acid, Diabetes, Myocardial ischemia/reperfusion injury