Oxygen-derived free radicals (O2 -, H2O2, OH·) are produced during oxidative metabolism, ischemia and reperfusion, and cardiopulmonary bypass (CPB). When oxygen free radical production exceeds scavening capacity, peroxidation of structural lipids in cell membranes can occur with potentially injurious consequences. In this prospective study, 45 patients were evaluated to determined the effect of CPB on oxygen free radical generation. Twenty patients in group I were controls. Exogenous oxygen free radical antioxidants were administered before bypass to patients in group II (n = 15, mannitol) and group III (n = 10, allopurinol). In group I, plasma H2O2 increased during extracorporeal circulation from 65 ± 6.0 to 125 ± 12 μM/ml (p < .001). At similar sampling intervals, plasma H2O2 levels were significantly lower in group II (p < .03) and group III (p < .05) when compared with those in group I. Red blood cell H2O2 did not change in group I or group II. White blood cell H2O2 levels decreased in group I (p < .04) and group II during CPB. (Intracellular concentrations of H2O2 were not obtained in group III patients). We conclude that cytotoxic oxygen radicals are generated during CPB and that pretreatment with free radical antioxidants, mannitol or allopurinol, may minimize the free radicals available for lipid peroxidation of biomembranes.
|Original language||English (US)|
|Issue number||5 II MONOGR. 125|
|State||Published - 1986|
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine