title: Effect of external Ca2+ on the spontaneous and the various stimuli-induced acetylcholine release from guinea-pig ileum myenteric plexus.
abstract: Effect of external Ca2+ concentration ([Ca2+]o) on spontaneous and various types of stimuli-induced acetylcholine (ACh) release from guinea-pig ileum myenteric plexus was studied. Electrical field stimulation- or high-K+-induced ACh release increased with the increment of [Ca2+]o. On the other hand, the spontaneous and the nicotine-induced ACh release increased up to 0.45 mM [Ca2+]o and then declined progressively as [Ca2+]o was raised. Qualitatively similar results were obtained with dimethylphenylpirerazinium-, 5-hydroxytryptamine- and substance P-induced ACh release. These results were discussed in terms of the stabilizing effect of Ca2+.
mesh_terms: D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D004558:Electric Stimulation; D007082:Ileum / Q000187:drug effects / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D009197:Myenteric Plexus / Q000187:drug effects / Q000378:metabolism*; D009538:Nicotine / Q000494:pharmacology; D013268:Stimulation, Chemical
chemical_list: D009538:Nicotine; D000109:Acetylcholine; D002118:Calcium