The precarious antioxidant defenses of the preterm infant

Oxygen radicals are considered to be major causative factors in many illnes ses of preterm infants. This article reviews the antioxidant defenses in im mature animals and preterm infants, and attempts to quantitate their vulner abilities to oxidants. Sources of oxidants, including hyperoxia, iron, pare nteral nutrition, nitric oxide, and pro-oxidants, and their impact on immat ure antioxidant defenses are discussed. Genetic manipulations of antioxidan t enzymes such as knockout and transgenic mice models are reviewed. The var ious clinical and investigational antioxidant therapies in animals and huma ns and difficulties in the design of antioxidant therapy studies are explor ed.