Impairment of brain kynurenic acid production by glutamate metabotropic receptor agonists.
The role of glutamatergic mechanisms in kynurenic acid (KYNA) production was evaluated in vitro. The selective ionotropic agonists NMDA, kainate and AMPA did not affect KYNA synthesis. Agonists of metabotropic (mGLU) and ionotropic receptors: quisqualate, L-glutamate and L-aspartate as well as agonists of mGLU receptors: (+/-)-1-aminocyclopentane-trans-1,3-dicarboxylic acid (t-ACPD) and L-(+)-2-amino-4-phosphonobutyric acid (L-AP4) diminished KYNA production with different potency. None of the studied mGLU antagonists such as (S)-4-carboxyphenylglycine, alpha-ethylglutamic acid or (RS)-alpha-methylserine-O-phosphate affected the basic or L-glutamate-inhibited synthesis of KYNA. It might be hypothesized that the impairment of KYNA production following the application of mGLU receptor agonists is related to their effects exerted upon the novel subtype of mGLU receptor.
Urbanska
E M
EM
Department of Pharmacology and Toxicology, Medical University School, Lublin, Poland.
Kocki
T
T
Saran
T
T
Kleinrok
Z
Z
Turski
W A
WA
D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D003515:Cycloleucine / Q000031:analogs & derivatives / Q000494:pharmacology; D066298:In Vitro Techniques; D007608:Kainic Acid / Q000494:pharmacology; D007736:Kynurenic Acid / Q000378:metabolism*; D008297:Male; D016202:N-Methylaspartate / Q000494:pharmacology; D016318:Quisqualic Acid / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D018094:Receptors, Metabotropic Glutamate / Q000819:agonists* / Q000037:antagonists & inhibitors; D012964:Sodium / Q000494:pharmacology; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology
D018094:Receptors, Metabotropic Glutamate; D003515:Cycloleucine; C036361:1-amino-1,3-dicarboxycyclopentane; D016202:N-Methylaspartate; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D016318:Quisqualic Acid; D012964:Sodium; D007736:Kynurenic Acid; D007608:Kainic Acid