title: The NO-cGMP pathway in neonatal rat dorsal horn.
abstract: Incubation of slices of neonatal rat spinal cord with nitric oxide donor compounds produced marked elevations in cyclic guanosine 3',5' monophosphate (cGMP) levels. The excitatory amino acid receptor agonists N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) produced smaller increases, which were blocked by the nitric oxide synthase (NOS) inhibitor L-NG-nitroarginine (NOArg), indicating that these cGMP responses were mediated by nitric oxide. Immunocytochemistry revealed that, in response to NMDA, cGMP accumulated in a population of small cells and neuropil in laminae II and III of the dorsal horn. This area was also shown, by reduced nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase histochemistry, to contain NOS. These observations suggest that, in the rat spinal cord, NMDA receptor activation is linked to the formation of NO and, hence, of cGMP. This pathway is located selectively in the superficial dorsal horn, consistent with a role in the processing of nociceptive signals.
authors.affiliation: Department of Veterinary Preclinical Sciences, University of Liverpool, UK.
authors.forename: R
authors.initials: R
authors.lastname: Morris
authors.forename: E
authors.initials: E
authors.lastname: Southam
authors.forename: S R
authors.initials: SR
authors.lastname: Gittins
authors.forename: J
authors.initials: J
authors.lastname: de Vente
authors.forename: J
authors.initials: J
authors.lastname: Garthwaite
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000037:antagonists & inhibitors; D000818:Animals; D000831:Animals, Newborn; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D015415:Biomarkers; D006152:Cyclic GMP / Q000096:biosynthesis / Q000502:physiology*; D005260:Female; D005978:Glutathione / Q000031:analogs & derivatives / Q000494:pharmacology; D008297:Male; D016202:N-Methylaspartate / Q000494:pharmacology; D009252:NADPH Dehydrogenase / Q000032:analysis; D009419:Nerve Tissue Proteins / Q000032:analysis; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase; D019335:Nitroarginine; D009599:Nitroprusside / Q000494:pharmacology; D009603:Nitroso Compounds / Q000494:pharmacology; D010146:Pain / Q000503:physiopathology; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects / Q000502:physiology*; D026422:S-Nitrosoglutathione; D015290:Second Messenger Systems; D015398:Signal Transduction / Q000187:drug effects; D013116:Spinal Cord / Q000187:drug effects / Q000502:physiology*; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology
chemical_list: D015415:Biomarkers; D009419:Nerve Tissue Proteins; D009603:Nitroso Compounds; D016194:Receptors, N-Methyl-D-Aspartate; D009599:Nitroprusside; D019335:Nitroarginine; D009569:Nitric Oxide; D026422:S-Nitrosoglutathione; D016202:N-Methylaspartate; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D001120:Arginine; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; D009252:NADPH Dehydrogenase; D005978:Glutathione; D006152:Cyclic GMP