Increased levels of nitrogen oxides and lipid peroxidation in the rat brain after soman-induced seizures.

We have investigated the effect of soman-induced seizures on rat brain levels of nitrogen oxides (NOx) and lipid peroxidation (LPO) 30 min and 24 h after intoxication. Following administration of soman (90 microg/kg s.c.), acetylcholinesterase activity was reduced to <10% of control after 30 min, whereas some de novo synthesis had occurred after 24 h. Significant increases in the LPO products malondialdehyde (MDA) and (E)-4-hydroxy-2-nonenal (4-HNE) were seen in the cortex, hippocampus, striatum, thalamus and medulla-pons 30 min after administration. A significant increase in the brain NOx levels, suggesting an increase in NO production, was seen in the cortex after 30 min and in the hippocampus and the striatum after 24 h. No significant changes were observed in cerebellum. These data suggest the possibility that free radical reactions may be a primary cause of neuronal degeneration after soman intoxication.