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On the blockade of acetylcholine release at mouse motor nerve terminals by β‐bungarotoxin and crotoxin
Author(s) -
Rowan E.G.,
Pemberton K.E.,
Harvey A.L.
Publication year - 1990
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1990.tb15799.x
Subject(s) - acetylcholine , blockade , motor nerve , bungarotoxin , neuromuscular junction , motor endplate , neuroscience , pharmacology , chemistry , acetylcholine receptor , medicine , biology , receptor
1 β‐Bungarotoxin and crotoxin are phospholipose A 2 neurotoxins, which block irreversibly the evoked release of acetylcholine from motor nerve terminals of mouse triangularis sterni preparations. 2 Extracellular recording of nerve terminal action potentials reveal that inhibition of transmitter release is not associated with failure of the action potential to invade nerve terminals. 3 When evoked transmitter release (measured as intracellularly recorded endplate potentials) was blocked by β‐bungarotoxin, spontaneous acetylcholine release was stimulated as in control experiments by K + ‐induced depolarization and by the Ca 2+ ‐ionophore A23187. 4 The site of action of the toxins remains to be elucidated but would appear to be associated with the coupling of action potential induced‐depolarization to the release mechanism, rather than with the release mechanism itself.