Total hydroperoxide and advanced oxidation protein products in preterm hypoxic babies

Previous studies have shown that plasma lipoproteins are a common target of free radical-induced oxidative stress in hypoxic newborn infants. In contr ast to lipids, the reaction of proteins with various oxidants during hypoxi a has not been extensively studied. We tested the hypothesis that tissue hy poxia results in increased production of protein oxidation in cord blood of preterm newborns. Heparinized blood samples of 39 hypoxic and 16 control p reterm newborns were obtained from the umbilical vein, after cord clamping immediately after delivery. Plasma levels of total hydroperoxide (TH), adva nced oxidation protein products (AOPP),hypoxanthine (Hx), xanthine (Xa), an d uric acid (UA) were measured. Higher Hx, Xa, UA, TH, and AOPP levels were found in hypoxic newborn infants than in controls. Statistically significa nt correlations were observed between: TH and Hx (r = 0.54, p = 0.003, n = 28), AOPP and Hx (r = 0.64 p = 0.0001, n = 27), and TH and AOPP plasma leve ls (r = 0.50: p = 0.02, n = 21). In summary, TH, AOPP, Hx, Xa, and UA produ ction is increased in fetal blood during hypoxia. The more severe the hypox ia, the higher the lipid and protein damage by free radicals.