Article date: 1992/12/1
PubMed ID: 1282467
Journal name: European journal of pharmacology (ISSN: 0014-2999)
A synthetic analog of philanthotoxin-433, philanthotoxin-343 (PhTX-343), was tested in hippocampal pyramidal neurons in vitro. PhTX-343 (2 microM) did not significantly change synaptic transmission mediated by AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid)/kainate receptors in the CA1 region of hippocampus. However, PhTX-343 significantly suppressed both the synaptic N-methyl-D-aspartate receptor-induced current (NMDA) obtained in the presence of CNQX(6-cyano-7-nitroquinoxaline-2,3-dione)/picrotoxin (10 microM) and the directly evoked NMDA receptor-induced current to pressure ejection of NMDA in the presence of tetrodotoxin (0.5 microM). A short transient facilitation of both types of NMDA response was seen immediately after the beginning of PhTX-343 application. Our results suggest that at high concentration (2 microM) PhTX-343 inhibits the NMDA-gated current, while the early facilitation occurred during an initial low concentration of the compound. Both facilitative and depressive actions of PhTX-343 are localized at the postsynaptic membrane.
Author List: Fedorov N B, Screbitsky V G, Reymann K G
Publication Types: Journal Article; Research Support, Non-U.S. Gov't
Substances mentioned in the article: Phenols; Polyamines; Quinoxalines; Receptors, AMPA; Receptors, Glutamate; Receptors, N-Methyl-D-Aspartate; philanthotoxin 343; Ibotenic Acid; Tetrodotoxin; N-Methylaspartate; 6-Cyano-7-nitroquinoxaline-2,3-dione; alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid;
Mesh terms: 6-Cyano-7-nitroquinoxaline-2,3-dione; Animals; Hippocampus/cytology; Ibotenic Acid/analogs & derivatives; N-Methylaspartate/pharmacology; Neurons/drug effects; Phenols/pharmacology; Polyamines/pharmacology; Quinoxalines/pharmacology; Rats; Rats, Wistar; Receptors, AMPA; Receptors, Glutamate/drug effects; Receptors, N-Methyl-D-Aspartate/drug effects; Synaptic Transmission/drug effects; Tetrodotoxin/pharmacology; alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid;