MARKERS OF OXIDATIVE STRESS AND ANTIOXIDANT ACTIVITY IN PLASMA AND ERYTHROCYTES IN NEONATAL RESPIRATORY-DISTRESS SYNDROME

Markers of oxidative stress and antioxidant activity in plasma and ery throcytes were studied for 14 d after birth in infants with neonatal r espiratory distress syndrome (n = 9) and controls (n = 36). In plasma, the total radical trapping antioxidant capacity and the chain-breakin g antioxidants vitamin C, sulfhydryl groups and bilirubin were similar . The differences in uric acid levels were not consistent, but vitamin E levels and vitamin E/total-lipid ratio were lower in the neonatal r espiratory distress group (p < 0.01). In erythrocytes, the antioxidant enzymes glutathione peroxidase, glutathione reductase and superoxide dismutase did not differ postnatally. Indicators of oxidative damage i n plasma (sulfhydryl/protein ratio and thiobarbituric acid reactive su bstances) showed the same postnatal course in both groups and were not influenced by oxygen therapy. In erythrocytes the reduced/oxidized gl utathione ratio showed no consistent differences. In conclusion, this study, using erythrocytes and plasma, does not provide convincing evid ence of oxidative damage and diminished antioxidant defenses in preter m infants with neonatal respiratory distress syndrome.