Lipid peroxidation in neonatal mouse brain subjected to two different types of hypoxia

To elucidate the role of free radicals in the pathogenesis of neonatal hypoxic encephalopathy, we determined the content of thiobarbituric acid reactants (TBARs), as an index of lipid peroxidation related with a free radical reaction, in the brains of newborn mice during hypoxia and recovery from hypoxia. Hypoxic stress was induced by 100% nitrogen gas breathing (N2 group) or 100% carbon dioxide gas breathing (CO2 group). TBARs increased with 20 minutes of hypoxia and returned to the control level during the recovery period in both groups. The increase in TBARs in the CO2 group was greater than that in the N2 group. These results may suggest that free radical reaction occurs during the hypoxic period and that CO2 hypoxia is more effective on free radical production in the newborn brain than N2 hypoxia.