title: Modulation by acetylcholine of the electrically-evoked release of [3H]-acetylcholine from the ileum of the guinea-pig.
abstract: 1 Acetylcholine (ACh) stores within neurones of the myenteric plexus of the guinea-pig were labelled with [3H]-choline and the influence of unlabelled ACh, atropine, or atropine and unlabelled ACh on the electrically-evoked output of [3H]-ACh was evaluated. 2 Electrical transmural stimulation (5 Hz) of the ileum led to an increase in the output of [3H]-ACh over that released spontaneously. Superfusion with unlabelled ACh (6.8 microM) caused a marked reduction in the release of [3H]-ACh which was reversed by atropine (3.5 microM). Atropine itself had no effect on the electrically-evoked [3H]-ACh. 3 These experiments provide further evidence for the existence in the guinea-pig ileum of neuronal muscarinic receptors for ACh subserving an inhibitory role on transmitter release.
mesh_terms: D000109:Acetylcholine / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D002794:Choline / Q000378:metabolism; D004558:Electric Stimulation; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D066298:In Vitro Techniques; D008297:Male; D009411:Nerve Endings / Q000378:metabolism; D010275:Parasympathetic Nervous System / Q000378:metabolism; D013997:Time Factors
chemical_list: D002794:Choline; D000109:Acetylcholine