Article date: 1989/10/1
PubMed ID: 2682343
Journal name: Neuropharmacology (ISSN: 0028-3908)
The depolarising population response to the excitatory amino acids, quisqualate and AMPA, in slices of cerebral cortex of the rat have been compared. Their respective dose-response curves had a similar maximum but the slope of the curve for AMPA was consistently steeper than that for quisqualate. The dose-response curves for AMPA had a mean log EC50 of -5.18 +/- 0.05, which was significantly different from -4.62 +/- 0.07 the mean log EC50 of the dose-response curves for quisqualate. Responses to both agonists were antagonised by kynurenic acid, barbiturates and gamma-DGT to a similar extent. The antagonism by kynurenate appeared to be competitive whilst the barbiturates were evidently noncompetitive antagonists. These results are in agreement with claims that quisqualate and AMPA act at a similar recognition site. The differences in the slopes of the dose-response curves for quisqualate and AMPA may be explained by the differences in the cellular uptake of the two agonists and/or by differences in efficacy.
Author List: Horne A L, Simmonds M A
Publication Types: Journal Article; Research Support, Non-U.S. Gov't
Substances mentioned in the article: Neuromuscular Depolarizing Agents; Oxadiazoles; Oxazoles; Glutamine; Taurine; Ibotenic Acid; alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; Quisqualic Acid; glutaurine; Kynurenic Acid; Pentobarbital;
Mesh terms: Animals; Cerebral Cortex/cytology; Dose-Response Relationship, Drug; Drug Interactions; Glutamine/pharmacology; Ibotenic Acid/antagonists & inhibitors; In Vitro Techniques; Kynurenic Acid/pharmacology; Male; Neuromuscular Depolarizing Agents/antagonists & inhibitors; Oxadiazoles/antagonists & inhibitors; Oxazoles/pharmacology; Pentobarbital/pharmacology; Quisqualic Acid; Rats; Rats, Inbred Strains; Taurine/pharmacology; alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid;