Changes in vitamin C and vitamin E during oxidative stress in myocardial reperfusion

Injury to the myocardial tissue due to ischemia and reperfusion occurs because of imbalance between the formation of oxidants and available antioxidants in the heart. Levels of vitamin C (ascorbic acid) and vitamin E (alpha--tocopherol) were evaluated in 52 patients of acute myocardial infarction (AMI) treated by streptokinase. They were further divided into reperfused group (39 patients) and non-reperfused group (13 patients). Twenty normal healthy subjects served as controls. Vitamin C and vitamin E were estimated in study group before and after thrombolytic therapy and in controls. Vitamin C levels were low in AMI cases as compared to controls (8.74 +/- 1.87 and 10.63 +/- 3.26 mg/L, respectively, P < 0.001). Trend of fall in vitamin C levels in the two study groups was not statistically significant. Vitamin E levels declined from 12.19 +/- 6.71 to 9.96 +/- 6.50 mg/L by 4 hours which was significant (P < 0.01) in the reperfused group, but the change in non-reperfused group (9.28 +/- 6.37 to 9.35 +/- 6.07 mg/dL by 4 hours) was non-significant. This is because of increased consumption of this antioxidant in suppressing the oxidative stress which occurs with reperfusion. Vitamin E can be proposed as a valid marker for reperfusion.