title: Regulation of vascular tone by S-nitroso-myoglobin.
abstract: Myoglobin (Mb) is a haem protein present in skeletal, cardiac and smooth muscle where it facilitates the transfer of O(2) from the extracellular matrix to the cell cytosol in a cycle termed 'facilitated O(2)-diffusion'. In addition, we showed recently that recombinant human Mb binds endothelium-derived relaxant factor - nitric oxide ((.-)NO) - via formation of both nitrosyl-haem iron and S-nitroso-myoglobin (S-NO-Mb). S-NO-Mb represents a novel form of endothelium-derived relaxant factor (EDRF) that may be important in maintaining optimal (.-)NO concentrations in the human vasculature. In this study we aim to show that: (i) S-nitrosation of oxygenated ferrous myoglobin (oxyMb) can compete with the rapid oxidation of (.-)NO by oxyMb; and (ii) S-NO-Mb retains characteristics of physiological EDRF.
authors.affiliation: Vascular Biology Group, ANZAC Research Institute, Hospital Road, Concord Repatriation General Hospital, Concord, New South Wales, Australia.
authors.forename: Benjamin S
authors.initials: BS
authors.lastname: Rayner
authors.forename: Ben J
authors.initials: BJ
authors.lastname: Wu
authors.forename: Mark
authors.initials: M
authors.lastname: Raftery
authors.forename: Roland
authors.initials: R
authors.lastname: Stocker
authors.forename: Paul K
authors.initials: PK
authors.lastname: Witting
mesh_terms: D000818:Animals; D001011:Aorta; D045462:Endothelium-Dependent Relaxing Factors / Q000138:chemical synthesis / Q000494:pharmacology*; D006801:Humans; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000502:physiology; D009211:Myoglobin / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D015538:Nitrosation; D011817:Rabbits; D026403:S-Nitrosothiols / Q000737:chemistry; D014664:Vasodilation / Q000187:drug effects*
chemical_list: D045462:Endothelium-Dependent Relaxing Factors; D009211:Myoglobin; D026403:S-Nitrosothiols; C031560:myoglobin nitroxide; C017595:oxymyoglobin