Article date: 1990/5/1
PubMed ID: 2160837
Journal name: Neuron (ISSN: 0896-6273)
Pharmacological characterization of Zn2+ effects on glutamate ionotropic receptors was investigated in Xenopus oocytes injected with rat brain mRNA, using a double microelectrode, voltage-clamp technique. At low concentration, Zn2+ inhibited NMDA currents (IC50 = 42.9 +/- 1.3 microM) and potentiated both AMPA (EC50 = 30.0 +/- 1.2 microM) and desensitized kainate responses (EC50 = 13.0 +/- 0.1 microM). At higher concentrations, Zn2+ inhibited non-NMDA responses with IC50 values of 1.3 +/- 0.1 mM and 1.2 +/- 0.3 mM for AMPA and kainate, respectively. The potentiation of AMPA or quisqualate currents by Zn2+ was more than 2-fold, whereas that of the kainate current was only close to 30%. This potentiating effect of Zn2+ on AMPA current modified neither the affinity of the agonist for its site nor the current-voltage relationship. In addition, 500 microM Zn2+ differentially affected NMDA and non-NMDA components of the glutamate-induced response. The possible physiological relevance of Zn2+ modulation is discussed.
Author List: Rassendren F A, Lory P, Pin J P, Nargeot J
Publication Types: Journal Article; Research Support, Non-U.S. Gov't
Substances mentioned in the article: Receptors, AMPA; Receptors, Amino Acid; Receptors, Cell Surface; Receptors, Kainic Acid; Receptors, N-Methyl-D-Aspartate; Receptors, Neurotransmitter; Ibotenic Acid; alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; Zinc;
Mesh terms: Animals; Dose-Response Relationship, Drug; Electric Conductivity/drug effects; Female; Ibotenic Acid/analogs & derivatives; Neurons/physiology; Oocytes/drug effects; Receptors, AMPA; Receptors, Amino Acid; Receptors, Cell Surface/drug effects; Receptors, Kainic Acid; Receptors, N-Methyl-D-Aspartate; Receptors, Neurotransmitter/drug effects; Xenopus laevis/physiology; Zinc/pharmacology; alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid;