Effect of α-tocopherol pretreatment on infarct size following of 90 minutes ischemia and 4 hours of reperfusion in dogs

The present study was designed to evaluate the effects of pretreatment with antioxidants on free radical mediated reprefusion injury. Five dogs were fed with α-tocopherol (1000 IU/kg, bw) for ten days prior to 90 min of left anterior descending coronary artery occlusion followed by 4 hours of reperfusion. Infarct size, serum and myocardial lipid peroxidation were measured in pretreated and in untreated animals. Infarct size, as percentage of myocardial tissue at risk in α-tocopherol pretreated animals was 5.86 ± 0.83 and was 39.35 ± 7.58 in the untreated animals. Following reprefusion in untreated group, the values of serum and myocardial tissue lipid peroxidation were significantly higher than observed values in α-tocopherol treated animals. α-tocopherol pretreatment significantly reduced the myocardial infarct size and percent necrosis in the left ventricular mass in comparison to the untreated animals. These results suggest that α-tocopherol pretreatment possibly helps in reducing infarct size.