title: Effects of N-methyl-D-aspartate on extracellular citrulline level in the rat nucleus accumbens.
abstract: In vivo microdialysis combined with high-performance liquid chromatography and electrochemical detection was used to study effects of intraaccumbal infusion of N-methyl-D-aspartate (NMDA) on the content of extracellular citrulline (a nitric oxide co-product) in the medial nucleus accumbens of Sprague-Dawley rats. The intraaccumbal NMDA infusion (10-1000 microM) dose-dependently increased the local dialysate citrulline levels (193+/-7% and 258+/-7% versus basal for the 100 and 1000 microM, respectively). The NMDA-induced increase of extracellular citrulline was completely prevented by intraaccumbal infusions through the dialysis probe both of 50 microM dizocilpine maleate (an NMDA antagonist) and of 0.5 mM N-nitro-L-arginine (a nitric oxide synthase inhibitor). Local infusion of N-nitro-L-arginine (0.5 mM) slightly decreased basal citrulline levels in the nucleus accumbens throughout the entire period of the infusion, whereas dizocilpine maleate (50 microM) had no long-lasting effect. These results suggest that NMDA receptor stimulation of the medial nucleus accumbens might cause a local nitric oxide synthase activation resulting in nitric oxide production in this brain area.
authors.affiliation: Laboratory of Higher Nervous Activity, I.P. Pavlov Institute of Physiology, Russian Academy of Sciences, 6 Admiral Makarov Embankment, St. Petersburg 199034, Russia. nbs@infran.ru
authors.forename: Natalia B
authors.initials: NB
authors.lastname: Saulskaya
authors.forename: Nellia V
authors.initials: NV
authors.lastname: Fofonova
mesh_terms: D000818:Animals; D001120:Arginine / Q000494:pharmacology; D002956:Citrulline / Q000378:metabolism*; D016291:Dizocilpine Maleate / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005110:Extracellular Space / Q000187:drug effects*; D008297:Male; D017551:Microdialysis / Q000379:methods; D016202:N-Methylaspartate / Q000494:pharmacology*; D009714:Nucleus Accumbens / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D004791:Enzyme Inhibitors; D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D002956:Citrulline; D016202:N-Methylaspartate; D016291:Dizocilpine Maleate; D001120:Arginine