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

ABSTRACT

The present study was designed to evaluate the effects of pretreatment with antioxidants on free radical mediated reprefusion injury. Five dogs were fed with alpha-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 alpha-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 alpha-tocopherol treated animals. alpha-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 alpha-tocopherol pretreatment possibly helps in reducing infarct size.