Suppression of a calcium current by CNQX and kynurenate.
During our investigation of a sustained high voltage-activated (HVA) calcium current in retinal horizontal cells, we found that the glutamate receptor antagonists CNQX and kynurenate but not AP7 reversibly reduced the peak amplitude of the HVA current. Changes in the HVA current kinetics or activation voltage were not apparent; there was only a reduction in the peak current. The novel effects of these antagonists on HVA calcium currents reported here could have an impact on many studies involving glutamatergic synaptic transmission.
D015763:2-Amino-5-phosphonovalerate / Q000031:analogs & derivatives*; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D000596:Amino Acids / Q000494:pharmacology; D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002478:Cells, Cultured; D004594:Electrophysiology; D018691:Excitatory Amino Acid Antagonists; D007051:Ibotenic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D007059:Ictaluridae; D007736:Kynurenic Acid / Q000494:pharmacology*; D011810:Quinoxalines / Q000494:pharmacology*; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors; D012160:Retina / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid
D000596:Amino Acids; D000927:Anticonvulsants; D002121:Calcium Channel Blockers; D018691:Excitatory Amino Acid Antagonists; D011810:Quinoxalines; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; D007051:Ibotenic Acid; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D015763:2-Amino-5-phosphonovalerate; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D007736:Kynurenic Acid; C031231:2-amino-7-phosphonoheptanoic acid