Regulation of vascular tone by S-nitroso-myoglobin.
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.
Rayner
Benjamin S
BS
Vascular Biology Group, ANZAC Research Institute, Hospital Road, Concord Repatriation General Hospital, Concord, New South Wales, Australia.
Wu
Ben J
BJ
Raftery
Mark
M
Stocker
Roland
R
Witting
Paul K
PK
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*
D045462:Endothelium-Dependent Relaxing Factors; D009211:Myoglobin; D026403:S-Nitrosothiols; C031560:myoglobin nitroxide; C017595:oxymyoglobin