Diminished protection against copper-induced lipid peroxidation by cord blood plasma of preterm and term infants

Background: Blood plasma of neonates is less able to inhibit iron induced lipid peroxidation than plasma of older patients. Copper, also a powerful pro-oxidant, may accumulate in ill babies because of excess intake or decreased excretion. We assessed in vitro the ability of plasma of neonates to inhibit copper induced peroxidation damage. Methods: Peroxidation of phospholipid liposomes, induced by CuCl₂, was measured with a thiobarbituric acid assay. The ability of plasma from venous blood of adults and cord blood of babies to inhibit peroxidation was compared. The levels of the copper binding plasma proteins, albumin and ceruloplasmin, were also measured. Results: Protection against copper induced lipid peroxidation was much higher with adult plasma compared to neonatal plasma. Despite their lower albumin and ceruloplasma levels the protection by the plasma of preterm babies was higher than that of the term babies. Conclusions: At birth, babies have a limited ability to inhibit copper induced oxidative damage in vitro. Postnatal studies are needing to assess the influence of maturation and nutrition on these findings and their relevance in diseases induced by reactive oxygen species.