[Modulatory effects of taurine on the release of acetylcholine from the central nervous system of an insect, the cockroach (Periplaneta americana L.)].
Taurine, when bath-applied to the sixth abdominal ganglion of the cockroach Periplaneta americana L. produced a reversible dose-dependent blockade of acetylcholine release determined by monitoring excitatory postsynaptic potentials (EPSPs) using the single-fibre oil-gap technique and mannitol-gap technique. The depressant synaptic effect of taurine was not antagonized either with external high calcium concentration or by 4-aminopyridine which is known to increase presynaptic calcium fluxes in other tissues. Inhibition of the taurine blockade by theophylline suggests competition between these molecules in the excitation-secretion coupling. The action of taurine was unaffected by 6-aminomethyl-3-methyl-4H-1,2,4-benzothiadiazine-1, 1-dioxide hydrochloride (TAG) or bicuculline. The taurine-induced EPSP suppression was reduced by picrotoxin but was unaffected by low chloride saline. The possible mechanisms and sites of taurine action are discussed.
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002490:Central Nervous System / Q000187:drug effects / Q000378:metabolism; D002712:Chlorides / Q000378:metabolism; D003058:Cockroaches / Q000378:metabolism*; D004594:Electrophysiology; D007478:Iontophoresis; D008564:Membrane Potentials / Q000187:drug effects; D011950:Receptors, Cholinergic / Q000502:physiology; D013569:Synapses / Q000187:drug effects / Q000502:physiology; D013654:Taurine / Q000494:pharmacology*
D002712:Chlorides; D011950:Receptors, Cholinergic; D013654:Taurine; D000109:Acetylcholine; D002118:Calcium
Effets modulateurs de la taurine sur la libération d'acetylcholine dans le système nerveux central d'un insecte, la blatte (Periplaneta americana L.).