title: Ciguatoxin-induced changes in acetylcholine release and in cytosolic calcium levels.
abstract: In this communication we summarize our current knowledge concerning the mode of action of ciguatoxin (CTX) on acetylcholine (ACh) release either from motor nerve terminals or from pure cholinergic synaptosomes. The results obtained indicate that CTX affects Ca(2+)-dependent ACh release via distinct actions mediated by Na+ which alter presynaptic excitability and Ca2+ influx through both voltage-sensitive channels and the reversed operation of the Na+/Ca2+ exchange system. The external calcium-independent ACh release induced by CTX in motor terminals seems to be due to a Na(+)-dependent and tetrodotoxin-sensitive mechanism which mobilizes Ca2+ from intraterminal stores, as determined by fluorometrical recordings in single mouse neuroblastoma x rat glioma NG108-15 cells.
authors.affiliation: Département de Neuropharmacologie et de Neurochimie, Centre National de la Recherche Scientifique, Gif-sur-Yvette, France.
authors.forename: J
authors.initials: J
authors.lastname: Molgo
authors.forename: T
authors.initials: T
authors.lastname: Shimahara
authors.forename: Y M
authors.initials: YM
authors.lastname: Gaudry-Talarmain
authors.forename: J X
authors.initials: JX
authors.lastname: Comella
authors.forename: A M
authors.initials: AM
authors.lastname: Legrand
mesh_terms: D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002922:Ciguatoxins / Q000494:pharmacology*; D003600:Cytosol / Q000378:metabolism; D009469:Neuromuscular Junction / Q000378:metabolism; D013574:Synaptosomes / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D002922:Ciguatoxins; D000109:Acetylcholine; D002118:Calcium