Lipid peroxide distribution in brain and the effect of hyperbaric oxygen.

Regional differences in peroxide levels in rat brain are relatively small but the highest levels were found in the substantia nigra. Lipid peroxides of rat whole brain were significantly increased (22%) immediately after exposure to oxygen at high pressure (OHP). However, this increase was transient. No significant difference from control was observed 3 h after exposure to OHP. The greatest increases were in the cerebral cortex and spinal cord. The olfactory bulb, caudate-putamen, globus pallidus, corpus callosum, septum, hypothalamus, substantia nigra, and inferior colliculus all showed moderate but significant increases, whereas the accumbens, thalamus, hippocampus, cerebellum, and amygdala showed no significant change. This regional difference in lipid peroxidation may indicate a regional susceptibility to the damaging effects of free radical reactions.