title: Is the internal calcium regulation altered in type A botulinum toxin-poisoned motor endings?
abstract: The hypothesis according to which botulinum A toxin blocks acetylcholine release from motor endings by stimulating intracellular Ca2+ disposal systems was tested by recording presynaptic membrane currents from poisoned muscles. Calcium and calcium-activated potassium currents displayed amplitudes, time courses and stimulation frequency-dependent inactivation similar to those observed in unpoisoned preparations. This indicates that poisoned endings are no more efficient than normal ones in dealing with Ca2+ overloads.
authors.affiliation: Laboratoire de Neurobiologie Cellulaire et Moléculaire, C.N.R.S., Gif sur Yvette, France.
authors.forename: A
authors.initials: A
authors.lastname: Mallart
authors.forename: J
authors.initials: J
authors.lastname: Molgó
authors.forename: D
authors.initials: D
authors.lastname: Angaut-Petit
authors.forename: S
authors.initials: S
authors.lastname: Thesleff
mesh_terms: D000818:Animals; D001905:Botulinum Toxins / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism* / Q000502:physiology; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D009046:Motor Neurons / Q000187:drug effects / Q000378:metabolism*; D009469:Neuromuscular Junction / Q000187:drug effects / Q000378:metabolism*; D011188:Potassium / Q000502:physiology; D011893:Rana esculenta
chemical_list: D015220:Calcium Channels; D001905:Botulinum Toxins; D011188:Potassium; D002118:Calcium