title: N-nitroso-melatonin releases nitric oxide in the presence of serotonin and its derivatives.
abstract: A novel reaction was observed between 5-hydroxytryptophan derivatives like serotonin and N-nitroso-melatonin (NOMela). This reaction decreased the concentration of serotonin by about 50% and generated initially as detectable products nitric oxide and melatonin with stoichiometrical yields. The other expected product, a serotonin-derived radical, could not be detected by electron spin resonance (ESR) spectrometry, probably because the self-decay of phenoxyl type radicals proceed at the diffusion-controlled limit. From the facts that the decay rate of NOMela corresponded very well with the nitric oxide releasing rate and that nitrite was the only thermodynamically stable nitrogen oxide-containing product, it is concluded that the NOMela-serotonin reaction proceeded quantitatively. The observed reaction might be a possibility to counteract a pharmacologically abnormal high serotonin concentration in various diseases.
authors.affiliation: Institut für Physiologische Chemie, Universitätsklinikum Essen, Essen, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Kopczak
authors.forename: Hans-Gert
authors.initials: HG
authors.lastname: Korth
authors.forename: Herbert
authors.initials: H
authors.lastname: de Groot
authors.forename: Michael
authors.initials: M
authors.lastname: Kirsch
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D008550:Melatonin / Q000737:chemistry*; D015394:Molecular Structure; D009569:Nitric Oxide / Q000737:chemistry*; D009573:Nitrites / Q000737:chemistry; D012701:Serotonin / Q000737:chemistry*
chemical_list: D009573:Nitrites; D009569:Nitric Oxide; D012701:Serotonin; D008550:Melatonin