title: Deferoxamine reduces and nitric oxide synthase inhibition increases neutrophil-mediated myotube injury.
abstract: We tested the contribution of reactive oxygen species (ROS), reactive nitrogen species (RNS) and the beta 2 integrin CD18 to neutrophil-mediated myotube injury. Human myotubes were cultured with human neutrophils in the presence or absence of inhibitors directed against ROS, RNS, and CD18. Muscle injury was assessed by a (51)Cr release assay. The inclusion of superoxide dismutase (50-500 U/ml) in the culture medium did not affect myotube injury. A significant protective effect was provided by including catalase (600-2400 U/ml), deferoxamine (1-2 mM), or anti-CD18 antibody (10 microg/ml) in the culture medium. S-Ethylisothiourea (500-1000 microM), an inhibitor of nitric oxide synthase (NOS), significantly increased myotube injury and reduced nitric oxide (NO) in cultures consisting of only myotubes. In conclusion, neutrophil-mediated skeletal muscle injury appears to be largely dependent on CD18-mediated neutrophil adhesion and iron-dependent hydroxyl radical production. In addition, skeletal muscle NOS activity may protect skeletal muscle against the injury caused by neutrophils.
authors.affiliation: Skeletal Muscle Physiology Laboratory, The University of Toledo, Toledo, OH 43606, USA.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: McLoughlin
authors.forename: Susan K
authors.initials: SK
authors.lastname: Tsivitse
authors.forename: Jessica A
authors.initials: JA
authors.lastname: Edwards
authors.forename: Brittany A
authors.initials: BA
authors.lastname: Aiken
authors.forename: Francis X
authors.initials: FX
authors.lastname: Pizza
mesh_terms: D018821:CD18 Antigens / Q000378:metabolism; D002374:Catalase / Q000494:pharmacology; D002857:Chromium / Q000378:metabolism; D002860:Chromium Radioisotopes / Q000378:metabolism; D017077:Culture Media, Conditioned; D003676:Deferoxamine / Q000494:pharmacology*; D006801:Humans; D017665:Hydroxyl Radical / Q000378:metabolism; D007502:Iron Chelating Agents / Q000494:pharmacology*; D007550:Isothiuronium / Q000031:analogs & derivatives* / Q000494:pharmacology; D008163:Luminescent Measurements; D018485:Muscle Fibers, Skeletal / Q000187:drug effects / Q000378:metabolism*; D009504:Neutrophils / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000494:pharmacology
chemical_list: D018821:CD18 Antigens; D002860:Chromium Radioisotopes; D017077:Culture Media, Conditioned; D007502:Iron Chelating Agents; D017382:Reactive Oxygen Species; D002857:Chromium; D007550:Isothiuronium; C007687:etiron; D017665:Hydroxyl Radical; D002374:Catalase; D019001:Nitric Oxide Synthase; D013482:Superoxide Dismutase; D003676:Deferoxamine