Formation of endogenous glutamatergic receptors antagonist kynurenic acid--differences between cortical and spinal cord slices.
Rat spinal cord slices produced kynurenic acid (KYNA) upon exposure to L-kynurenine. Aminooxyacetic acid, non-selective aminotransferase inhibitor, and L-glutamate, but neither N-methyl-D-aspartate (NMDA), alpha-amino-3-hydroxy-5-metyloisoxazolo-4-propionate (AMPA), nor kainate, diminished synthesis of KYNA. L-Glutamate action was less potent in spinal than in cortical slices. Metabotropic agonists, L-(+)-2-amino-4-phosphonobutyrate (L-AP4) and (+/-)-1-aminocyclopentane-trans-1,3-dicarboxylic acid (t-ACPD), used in concentrations inhibiting cortical KYNA synthesis, were ineffective in spinal cord. Spinal KYNA production seems less susceptible to inhibitory modulation.
Urbańska
E M
EM
Department of Pharmacology and Toxicology, Medical University, Jaczewskiego 8, 20-090 Lublin, Poland. ewau@galen.imw.lublin.pl
Chmielewski
M
M
Kocki
T
T
Turski
W A
WA
D000625:Aminooxyacetic Acid / Q000494:pharmacology; D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism*; D018691:Excitatory Amino Acid Antagonists / Q000378:metabolism*; D018698:Glutamic Acid / Q000494:pharmacology; D066298:In Vitro Techniques; D007736:Kynurenic Acid / Q000037:antagonists & inhibitors / Q000378:metabolism*; D007737:Kynurenine / Q000494:pharmacology; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D017470:Receptors, Glutamate / Q000187:drug effects / Q000378:metabolism*; D013116:Spinal Cord / Q000378:metabolism*; D000637:Transaminases / Q000037:antagonists & inhibitors
D018691:Excitatory Amino Acid Antagonists; D017470:Receptors, Glutamate; D000625:Aminooxyacetic Acid; D007737:Kynurenine; D018698:Glutamic Acid; D000637:Transaminases; D007736:Kynurenic Acid