OXIDATIVE STRESS AND LIPID PEROXIDATION IN THE NEWBORN

Abstract

Increasing appreciation of the causative role of oxidative injury in the development of many severe diseases of the newborn places great importance on the reliable assessment of lipid peroxidation. Lipid peroxidation in the erythrocyte membrane has been widely investigated but little has been reported on lipid peroxidation in the plasma The aim of the present paper was to evaluate lipid peroxidation and peroxidation tissue injury in the plasma of newborns using the concentration of Malondialdehyde (MDA). one of the several substances formed when lipid hydroperoxides break down in biological systems Twenty-one, healthy, full-term newborn infants, (10 male and 11 female), with an Apgar score of more than 8 at 1 min, were studied. Fifteen were born by vaginal delivery (VD) and 6 by elective cesaerean section (ECS) Hepannized blood samples were taken at birth from the cord blood and on the 4th day of life from a peripheral vein MDA levels were determined by fluorometric assay using the MDA Kit (Sobioda, Grenoble France) We found significantly lower concentrations of MDA at birth (2 81±1 34 nmol/mL. meant±SD) than on 4th day of life (4.35±1.98. P<0 0003) in total population. This difference was also observed in the two mode of delivery when considered separately. No statistically significant differences were found between the two groups nor between the sexes. These results clearly demonstrate a significant increase in lipid peroxidation after birth. We speculate that environmental changes in O2 concentration from fetal to postnatal life are sufficient to produce an increase in aerobic metabolism and in the rate of free radical generation The deficient antioxidant mechanisms at birth could impair normal fetal equilibrium between oxygen free radical generation and free radical detoxification