Regional lipid peroxidation and protein oxidation in rat brain after hyperbaric oxygen exposure

Reactive oxygen species may participate in development of neurological toxicity resulting from hyperbaric oxygen exposure. To explore the possibility that increased reactive O-2 metabolite generation may result in oxidative modification of lipids and proteins, rats were exposed to five atmospheres (gauge pressure) of O-2 until development of an electroencephalographic seizure. Lipid peroxidation (as thiobarbituric acid-reactive substances) and protein oxidation (as 2,4-dinitrophenyl-hydrazones)were measured in five brain regions. Oxidized and reduced confined to the frontal cortex and hippocampus, while protein oxidation (in both cytoplasmic and membranous fractions) and increased oxidized glutathione was evident throughout the brain. These results support a role for formation of reactive O-2 metabolites from hyperbaric O-2 exposure and suggest that protein oxidation, especially in soluble proteins, may be one of the most sensitive measures.