Release of [3H]GABA evoked by glutamate receptor agonists in cultured chick retina cells: effect of Ca2+.
The effect of glutamate receptor agonists (NMDA, kainate, quisqualate and AMPA) on the [Ca2+]i and on [3H]GABA release was studied in cultured chick embryonic retinal cells. The release of [3H]GABA evoked by NMDA, in the absence of Ca2+, was prevented by the NMDA receptor antagonist (+)-methyl-10,11-dihydro-5H-dibenzo[a,d]-cyclohepten-5,10-imine (MK-801), and that produced by kainate and quisqualate was prevented by 6-cyano-7-nitroquinoxaline-2,3-dioxine (CNQX). All the agonists tested increased the [Ca2+]i, and when the GABA transporter was blocked by 1-(2-(((diphenyl-methylene)amino)oxy)ethyl)-1,2,5,6-tetrahydro-3- pyridine-carboxylic acid (NNC-711), NMDA, AMPA or quisqualate, but not kainate, did not induce [3H]GABA release unless Ca2+ (1 mM) was present, showing that exocytotic release of [3H]GABA occurs in retinal cells under these conditions.
Ferreira
I L
IL
Department of Zoology, University of Coimbra, Portugal.
Duarte
C B
CB
Santos
P F
PF
Carvalho
C M
CM
Carvalho
A P
AP
D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002478:Cells, Cultured; D002642:Chick Embryo; D016291:Dizocilpine Maleate / Q000494:pharmacology; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology*; D018756:GABA Antagonists / Q000494:pharmacology; D007608:Kainic Acid / Q000494:pharmacology; D016202:N-Methylaspartate / Q000494:pharmacology; D009539:Nicotinic Acids / Q000494:pharmacology; D009557:Nipecotic Acids; D010091:Oximes / Q000494:pharmacology; D016318:Quisqualic Acid / Q000494:pharmacology; D012160:Retina / Q000187:drug effects* / Q000196:embryology / Q000378:metabolism; D014316:Tritium; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D018690:Excitatory Amino Acid Agonists; D018756:GABA Antagonists; D009539:Nicotinic Acids; D009557:Nipecotic Acids; D010091:Oximes; D014316:Tritium; C078793:NNC 711; D005680:gamma-Aminobutyric Acid; D016202:N-Methylaspartate; D016291:Dizocilpine Maleate; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D016318:Quisqualic Acid; D007608:Kainic Acid; D002118:Calcium