[Antioxidant enzyme activities in fetal and neonatal lung: lowered activities of these enzymes in children with RDS].

Lung tissue was obtained within 24 h of death from 49 fetuses and neonates (31 weeks gestation to 3 months post term). 24 neonates died from RDS, other neonates died from inherited heart abnormalities. All three antioxidant enzymes: superoxide dismutase (SOD), catalase and glutathione peroxidase (GSH-Px) activities increased with gestational age. After term, SOD increased further by 51-60 weeks, while GSPH-Px exhibited a transient increase between 41-50 weeks. Activities of these enzymes in lung of neonates who died after RDS were significantly lower, and the peroxidation processes were significantly higher. These results suggest existence of oxidative stress, i.e. overproduction of oxygen free radicals in lung neonates who died after RDS.