Defective oxidative metabolism in newborn neutrophils: discrepancy between superoxide anion and hydroxyl radical...

Investigation of oxidative metabolism in neutrophils (PMNs) from newborns was performed by measuring generation of superoxide anion (.O2-) and production of hydroxyl radical (.OH) in the resting state and after stimulation with opsonized zymosan or phorbol myristate acetate (PMA). Neutrophils from cord blood of ten term infants and normal adult controls were tested simultaneously. Cord PMNs generated significantly more .O2- than paired adult controls when stimulated with opsonized zymosan (P less than .01) and produced less .OH with PMA (P less than .005). When the amount of .O2- and .OH released by newborn PMNs with both stimuli was expressed as percent of values obtained from paired adult controls, there was a discrepancy in the generation of these two radicals: newborn PMNs produced relatively less .OH compared to .O2-. This decreased ability to produce .OH could underlie defective bactericidal activity in PMNs of neonates.