The actions of tetraethylammonium at the neuromuscular junction.
1. Tetraethylammonium (TEA) produces contractures in slow muscle fibres of the chick and the guinea-pig. 2. These contractures probably involve (a) the facilitation of the release of acetylcholine by TEA (b) direct stimulant action of TEA on the post-synaptic membrane with little accompanying depolarization. 3. Since microelectrode studies on fast twitch fibres indicate that TEA exerts a blocking action on the Na+/K+ ion channel of the end-plate it may be that TEA produces its direct contracture-inducing action in slow fibres by increasing Ca2+ influx.
D000818:Animals; D006801:Humans; D009119:Muscle Contraction / Q000187:drug effects; D009411:Nerve Endings / Q000187:drug effects; D009469:Neuromuscular Junction / Q000187:drug effects*; D013569:Synapses / Q000187:drug effects; D013757:Tetraethylammonium Compounds / Q000494:pharmacology*
D013757:Tetraethylammonium Compounds