ELECTRON-SPIN-RESONANCE MEASURE OF BRAIN ANTIOXIDANT ACTIVITY DURING ISCHEMIA REPERFUSION/

AN electron spin resonance technique was used to measure cerebral anti oxidant activity during asphyxial cardiac arrest and reperfusion. Ther e were significant decreases in ascorbate (48%), glutathione (44%), to tal thiols (42%), protein thiols (38%) and alpha-tocopherol (26%) in t he hippocampus 10 min after reperfusion (p < 0.05 vs respective baseli nes) but not during asphyxial cardiac arrest. The levels of antioxidan ts returned to baseline values by 120 min after reperfusion. The resul ts support the hypothesis that reperfusion from asphyxial cardiac arre st, but not arrest alone, produced a significant oxidative stress as r eflected by a depletion of both water and lipid soluble antioxidants. Furthermore, antioxidant depletion was transient, with normal antioxid ant levels observed 120 min, 24 h and 72 h after reperfusion. (C) 1998 Rapid Science Ltd.