TIME-COURSE OF OXIDATIVE STRESS DURING OPEN-HEART-SURGERY

Oxidative stress and subsequent lipid peroxidation have been suggested as pathogenetically important for postischaemic reperfusion injury. W e studied the time-course of oxidative stress in 14 adults undergoing cardiac surgery, evaluating serum levels of lipid peroxidation product s-diene conjugates (DC) and basal and Fe-stimulated thiobarbituric aci d reactive substances (TBARS, Fe-TEBARS)-as well as markers of blood a ntioxidant status-serum antioxidative capacity (AOC) and red blood cel l glutathione (RBC-GSH) at 6 perioperative time-points. Arterial TBARS were significantly increased 15 minutes after start of cardiopulmonar y bypass, 5 minutes after release of aortic cross-clamp and 15 minutes after cessation of bypass, compared with the preoperative levels (res pective means 20.8, 38.5, 34.8 vs 7.5 nmol/g protein, p < 0.05). AOC h ad decreased at these times (means 21.3, 18.1, 23.2 vs 34.9%, p < 0.05 ). The TB ARS changes correlated with AOC decrease (r = 0.30, p < 0.00 1). Changes in serum DC and RBC-GSH were not statistically significant . All lipid peroxidation parameters had returned to preoperative level s on the following morning, while antioxidative capacity remained supp ressed (28.1%, p < 0.05). These data demonstrate a definite time-cours e of oxidative stress markers in arterial blood during open-heart surg ery.