PLASMA ANTIOXIDANTS - EVIDENCE FOR A PROTECTIVE ROLE AGAINST REACTIVEOXYGEN SPECIES FOLLOWING CARDIAC-SURGERY

Total plasma antioxidant status (TPAS), lipid peroxide concentration ( LPX) and cardiac troponin T (cTnT) were measured in 24 patients underg oing coronary artery bypass grafting (CABG) with cardiopulmonary bypas s (CPB). Samples were obtained preoperatively and at 1.5 h. 6 h, 24 h and 72 h after CPB, The absolute TPAS values were significantly lower at 1.5 h, 6 h, 24 h and 72 h after CPB than were preoperative values ( P<0.05). The LPX concentration was significantly elevated at 1.5 h aft er CPB (P<0.05). Cardiac troponin T concentrations were significantly elevated at ail lime points postoperatively (P<0.05). Preoperative TPA S values were significantly correlated with the magnitude of fall in T PAS at 1.5 h (P < 0.05). The greater the fall in TPAS between 0 and 1. 5 hi the less LPX was formed between 0 and 1.5 h. The LPX at 1.5 h dis played a significant correlation with cTnT release from myocardial myo cytes (P<0.05). These data provide evidence for the first time that th e consumption of antioxidants during CABG surgery with CPB protects ag ainst the production of reactive oxygen species and subsequent myocyte necrosis. Furthermore, the availability of protective antioxidants is dependent upon preoperative TPAS.