The Roles of Dominance of the Nitric Oxide Fractions Nitrate and Nitrite in the Epilepsy-Prone EL Mouse Brain.

Abstract

BACKGROUND: Oxidative stress is thought to be closely related to epileptogenesis. We have previously reported that nitric oxide (NO) levels are higher in epilepsy-prone EL mice between the ages of 3 and 8 weeks than in control mice. However, NO is divided into two fractions, nitrite (NO) and nitrate (NO), which appear to play different roles in epileptogenesis. METHODS: NOand NOlevels were measured, in EL mice and the control mice, in the parietal cortex, which is thought to be the primary epileptogenetic center in EL mice, and measured in the hippocampus, which is thought to be the secondary center. RESULTS: NOlevels in the hippocampus and parietal cortex of the immature EL mice (3 to 8 weeks of age) were significantly higher than those in the control mice; NOlevels were significantly higher in the EL mice throughout the study period. The NOlevels were significantly higher than the NOlevels in the immature EL mice, but after the onset of ictogenesis at 10 weeks of age, the relative levels of the two fractions reversed. CONCLUSION: The reversal of the NO fraction distribution at the onset of seizures that we observed may be related to the developmental process of seizure susceptibility in the neural network of EL mice.