title: The stimulus-induced release of 5-hydroxytryptamine and tryptophan from superfused rat brain synaptosomes.
abstract: The synthesis of 5-hydroxytryptamine (5-HT) from 3H-tryptophan in rat forebrain synaptosomes was studied. Synaptosomes which had been preincubated with 3H-tryptophan were perfused with Krebs solution and the release of tryptophan, 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) was determined. K+ depolarization induced a Ca2+ -dependent release of 5-HT and tryptophan but had no effect on 5-HIAA efflux. This finding suggests that the release of tryptophan is unlikely to be a non-specific effect of depolarization.
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism* / Q000648:ultrastructure; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D066298:In Vitro Techniques; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D012701:Serotonin / Q000096:biosynthesis / Q000378:metabolism*; D013574:Synaptosomes / Q000378:metabolism*; D014364:Tryptophan / Q000378:metabolism*
chemical_list: D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D014364:Tryptophan; D011188:Potassium