title: Release of reactive oxygen and nitrogen species from contracting skeletal muscle cells.
abstract: A number of studies have indicated that exercise is associated with an increased oxidative stress in skeletal muscle tissue, but the nature of the increased oxidants and sites of their generation have not been clarified. The generation of extracellular reactive oxygen and nitrogen species has been studied in myotubes derived from an immortalized muscle cell line (H-2k(b) cells) that were stimulated to contract by electrical stimulation in culture. Cells were stimulated to contract with differing frequencies of electrical stimulation. Both induced release of superoxide anion and nitric oxide into the extracellular medium and caused an increase in extracellular hydroxyl radical activity. Increasing frequency of stimulation increased the nitric oxide generation and hydroxyl radical activity, but had no significant effect on the superoxide released. Additions of inhibitors of putative generating pathways indicated that contraction-induced NO release was primarily from neuronal NO synthase enzymes and that the superoxide released is likely to be generated by a plasma membrane-located, flavoprotein oxidoreductase system. The data also indicate that peroxynitrite is generated in the extracellular fluid of muscle during contractile activity.
authors.affiliation: School of Clinical Sciences, University of Liverpool, Liverpool L69 3GA, UK.
authors.forename: David M
authors.initials: DM
authors.lastname: Pattwell
authors.forename: David M
authors.initials: DM
authors.lastname: Patwell
authors.forename: Anne
authors.initials: A
authors.lastname: McArdle
authors.forename: Jennifer E
authors.initials: JE
authors.lastname: Morgan
authors.forename: Terence A
authors.initials: TA
authors.lastname: Patridge
authors.forename: Malcolm J
authors.initials: MJ
authors.lastname: Jackson
mesh_terms: D000818:Animals; D002396:Catechols / Q000378:metabolism; D002460:Cell Line; D045304:Cytochromes c / Q000378:metabolism; D062385:Hydroxybenzoates; D051379:Mice; D032342:Muscle Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009119:Muscle Contraction; D009566:Nitrates / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism; D010084:Oxidation-Reduction; D026361:Reactive Nitrogen Species / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D020156:Salicylic Acid / Q000378:metabolism / Q000494:pharmacology
chemical_list: D002396:Catechols; D062385:Hydroxybenzoates; D009566:Nitrates; D009573:Nitrites; D026361:Reactive Nitrogen Species; D017382:Reactive Oxygen Species; C009135:2,3-dihydroxybenzoic acid; D045304:Cytochromes c; D019001:Nitric Oxide Synthase; D020156:Salicylic Acid