Lipid peroxidation and changes in vitamin E levels during coronary artery bypass grafting

The effects of ischemia and reperfusion on arterial and coronary sinus vitamin E and thiobarbituric acid reactive substance levels were investigated in 10 patients undergoing routine coronary artery bypass grafting. Serial sampling was performed during bypass operations, before the initial period of crossclamping and at 30 seconds and 2, 5, and 10 minutes after final crossclamp removal. A net myocardial loss of vitamin E occurred in the first 5 minutes of myocardial reperfusion (0.84±0.21 μmol/mmol cholesterol; p<0.01). Myocardial vitamin E loss correlated positively with the total crossclamp time (p=-0.695; p<0.05) but was independent of cardiac enzyme release and duration of cardiopulmonary bypass