Nitric oxide production is decreased in the brain of the seizure susceptible EL mouse

To investigate nitric oxide production in the brain of the EL mouse, an inb red mutant strain of the ddY mouse that is susceptible to convulsive seizur es, we measured whole brain nitric oxide metabolites, and counted the numbe r of nitric oxide-producing cells in the parietal cortex and striatum, Nitr ic oxide metabolites in the brain and serum were determined by measuring le vels of nitrite plus nitrate. Nitric oxide-producing cells were demonstrate d histochemically by staining for nicotinamide adenine dinucleotide phospha te (NADPH) diaphorase. Levels of nitrite plus nitrate in the whole brain we re significantly lower than those of the control mice, although levels of n itrite plus nitrate in the serum did not differ between groups. There were significantly fewer NADPH-diaphorase-positive cells in the parietal cortex and striatum of the EL mouse compared to the ddY controls. These results su ggest that lower nitric oxide production in the brain may be related to the susceptibility of the EL mouse to convulsive seizures. (C) 1999 Elsevier S cience Inc.