Effect of soman on N-methyl-D-aspartate-stimulated [H-3]norepinephrine release from rat cortical slices

Effects of soman on N-methyl-D-aspartate (NMDA) evoked [H-3]norepinephrine (NE) release were examined in rat brain cortical slices. NMDA increased [H- 3]NE release in a concentration-dependent manner. Soman could inhibit the i ncrease evoked by NMDA, but carbachol, an agonist of cholinergic receptor, could potentiate the increase evoked by NMDA. Atropine (a selective muscari nic antagonist) attenuated the release of [H-3]NE induced by NMDA in the pr esence of carbachol or acetylcholine (ACh), but had no effect on the releas e of [H-3]NE induced by NMDA alone. Both d-tubocurarine tan antagonist of n icotinic receptor) and atropine had no effect on the release of [H-3]NE ind uced by NMDA in the presence of soman. These results suggested that soman h as a direct action at non-cholinergic sites, probably at NMDA receptors. (C ) 1998 Elsevier Science Ireland Ltd. All rights reserved.