Antagonist profile of 6,7-dichloro-3-hydroxy-2-quinoxalinecarboxylate at excitatory amino acid receptors in the neonatal rat spinal cord.
In the neonatal rat spinal cord, 6,7-dichloro-3-hydroxy-2- quinoxalinecarboxylate antagonised responses mediated at both N-methyl-D-aspartate (NMDA) and non-NMDA receptors. The antagonism of responses to NMDA was unsurmountable and mediated via an antagonist action at the allosterically-linked strychnine-insensitive glycine site. At non-NMDA receptors, 6,7-dichloro-3-hydroxy-2-quinoxalinecarboxylate appeared to act as a competitive antagonist at low concentrations and a non-competitive antagonist at higher concentrations. In contrast to published data, this antagonist did not distinguish between the responses mediated by DL-alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionate (AMPA) and kainate.
Birch
P J
PJ
Department of Neuropharmacology, Glaxo Group Research Ltd., Ware, Herts., U.K.
Grossman
C J
CJ
Hayes
A G
AG
D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism*; D007051:Ibotenic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D007608:Kainic Acid / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D017459:Receptors, Amino Acid; D011956:Receptors, Cell Surface / Q000187:drug effects*; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter / Q000187:drug effects; D013116:Spinal Cord / Q000187:drug effects*; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid
D011810:Quinoxalines; D017459:Receptors, Amino Acid; D011956:Receptors, Cell Surface; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter; D007051:Ibotenic Acid; C057665:6,7-dichloro-3-hydroxy-2-quinoxalinecarboxylic acid; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D007608:Kainic Acid