title: Isolation of a factor that reverses presynaptic inhibition of acetylcholine release.
abstract: A factor (Substance B) has been isolated from brain which reverses the presynaptically-modulated inhibition of evoked ACh release from both guinea-pig myenteric plexus-longitudinal muscle synaptosomes and the intact strip. Inhibitory modulating agents whose activity is reversed by Substance B include oxotremorine, 2-chloroadenosine, clonidine, and morphine. In addition to brain, Substance B is also present in heart and ileum but not in liver or kidney. As determined by Biogel P2 chromatography, this factor appears to have a molecular weight of around 700. It is not destroyed by preincubation with periodate, amylase, adenosine deaminase, pronase, trypsin, phospholipase C or carboxypeptidase Y.
mesh_terms: D015762:2-Chloroadenosine; D000109:Acetylcholine / Q000378:metabolism*; D000241:Adenosine / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D001921:Brain / Q000502:physiology*; D001923:Brain Chemistry; D003000:Clonidine / Q000494:pharmacology; D004246:Dimethylphenylpiperazinium Iodide / Q000494:pharmacology; D006168:Guinea Pigs; D009020:Morphine / Q000494:pharmacology; D009197:Myenteric Plexus / Q000502:physiology*; D009469:Neuromuscular Junction / Q000502:physiology*; D010095:Oxotremorine / Q000494:pharmacology; D010660:Phenylisopropyladenosine / Q000494:pharmacology; D013569:Synapses / Q000502:physiology*; D013574:Synaptosomes / Q000187:drug effects / Q000502:physiology*
chemical_list: D015762:2-Chloroadenosine; D010660:Phenylisopropyladenosine; D004246:Dimethylphenylpiperazinium Iodide; D010095:Oxotremorine; D009020:Morphine; D000241:Adenosine; D003000:Clonidine; D000109:Acetylcholine