title: Mechanical ventilation-induced oxidative stress in the diaphragm.
abstract: Prolonged mechanical ventilation (MV) results in oxidative damage in the diaphragm; however, it is unclear whether this MV-induced oxidative injury occurs rapidly or develops slowly over time. Furthermore, it is unknown whether both soluble (cytosolic) and insoluble (myofibrillar) proteins are equally susceptible to oxidation during MV. These experiments tested two hypotheses: 1). MV-induced oxidative injury in the diaphragm occurs within the first 6 h after the initiation of MV; and 2). MV is associated with oxidative modification of both soluble and insoluble proteins. Adult Sprague-Dawley rats were randomly divided into one of seven experimental groups: 1) control (n = 8); 2) 3-h MV (n = 8); 3). 6-h MV (n = 6); 4). 18-h MV (n = 8); 5). 3-h anesthesia-spontaneous breathing (n = 8); 6). 6-h anesthesia-spontaneous breathing (n = 6); and 7). 18-h anesthesia-spontaneous breathing (n = 8). Markers of oxidative injury in the diaphragm included the measurement of reactive (protein) carbonyl derivatives (RCD) and total lipid hydroperoxides. Three hours of MV did not result in oxidative injury in the diaphragm. In contrast, both 6 and 18 h of MV promoted oxidative injury in the diaphragm, as indicated by increases in both protein RCD and lipid hydroperoxides. Electrophoretic separation of soluble and insoluble proteins indicated that the MV-induced accumulation of RCD was limited to insoluble proteins with molecular masses of approximately 200, 120, 80, and 40 kDa. We conclude that MV results in a rapid onset of oxidative injury in the diaphragm and that insoluble proteins are primary targets of MV-induced protein oxidation.
authors.affiliation: Department of Execise and Sport Sciences, Center for Exercise Science, University of Florida, Gainesville, FL 32601, USA.
authors.forename: Murat A
authors.initials: MA
authors.lastname: Zergeroglu
authors.forename: Michael J
authors.initials: MJ
authors.lastname: McKenzie
authors.forename: R Andrew
authors.initials: RA
authors.lastname: Shanely
authors.forename: Darin
authors.initials: D
authors.lastname: Van Gammeren
authors.forename: Keith C
authors.initials: KC
authors.lastname: DeRuisseau
authors.forename: Scott K
authors.initials: SK
authors.lastname: Powers
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D015153:Blotting, Western; D001831:Body Temperature / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D003964:Diaphragm / Q000502:physiology*; D005260:Female; D006863:Hydrogen-Ion Concentration; D008054:Lipid Peroxides / Q000378:metabolism; D008124:Locomotion / Q000502:physiology; D009124:Muscle Proteins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism; D018384:Oxidative Stress / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D012121:Respiration, Artificial
chemical_list: D008054:Lipid Peroxides; D009124:Muscle Proteins; D017382:Reactive Oxygen Species