The effect of 2-amino-4-phosphonobutyrate (APB) on acetylcholine release from the rabbit retina: evidence for on-channel input to cholinergic amacrine cells.
The light-evoked release of acetylcholine (ACh) from the rabbit retina was taken as a measure of cholinergic amacrine cell activity. The glutamate analogue DL-(+/-)-2-amino-4-phosphonobutyric acid (APB) prevented the light-evoked release of ACh and also selectively abolished the ON-responses of ganglion cells and the ERG b-wave. It is concluded that the input to cholinergic amacrine cells involves mainly the depolarizing bipolar cells, which subserve ON-channels. L-(+)-stereoisomer of APB was 15 times more potent than the D-(-)-isomer in suppressing ACh release and the b-wave, suggesting that the mechanism of action of APB does not involve antagonism of excitatory amino acids.
D015763:2-Amino-5-phosphonovalerate; D000109:Acetylcholine / Q000378:metabolism*; D000613:Aminobutyrates / Q000494:pharmacology*; D000818:Animals; D007473:Ion Channels / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D009943:Organophosphorus Compounds / Q000494:pharmacology*; D010275:Parasympathetic Nervous System / Q000166:cytology*; D011817:Rabbits; D012160:Retina / Q000378:metabolism*; D009435:Synaptic Transmission; D014633:Valine / Q000031:analogs & derivatives / Q000494:pharmacology
D000613:Aminobutyrates; D007473:Ion Channels; D009943:Organophosphorus Compounds; D015763:2-Amino-5-phosphonovalerate; C012729:2-amino-4-phosphonobutyric acid; D014633:Valine; D000109:Acetylcholine