title: Altered antioxidant status in peripheral skeletal muscle of patients with COPD.
abstract: Despite the growing field of interest in the role of pulmonary oxidative stress in chronic obstructive pulmonary disease (COPD), barely any data are available with respect to antioxidant capacity in the peripheral musculature of these patients. The main objective of this study was to assess in detail the antioxidant status in skeletal muscle of patients with COPD. Biopsies from the vastus lateralis of 21 patients with COPD and 12 healthy age-matched controls were analysed. Total antioxidant capacity, vitamin E, glutathione, and uric acid levels were determined and the enzyme activities of superoxide dismutase, glutathione reductase, glutathione peroxidase, and glutathione-S-transferase were measured. Malondialdehyde was measured as an index of lipid peroxidation. The total antioxidant capacity and the uric acid levels were markedly higher in COPD patients than in healthy controls (25%, P = 0.006 and 24%, P = 0.029, respectively). Glutathione-S-transferase activity was also increased (35%; P = 0.044) in patients compared to healthy subjects. Vitamin E level was lower in patients than in controls (P < 0.05). The malondialdehyde level was not different between the two groups. It can be concluded that the muscle total antioxidant capacity is increased in patients with COPD. Together with the reduced vitamin E levels, the increased glutathione-S-transferase activity and normal levels of lipid peroxidation products, these findings suggest that the antioxidant system may be exposed to and subsequently triggered by elevated levels of reactive oxygen species.
authors.affiliation: Department of Respiratory Medicine, Nutrition Toxicology and Environment Research Institute, Maastricht University, Maastricht, The Netherlands. h.gosker@pul.unimaas.nl
authors.forename: Harry R
authors.initials: HR
authors.lastname: Gosker
authors.forename: Aalt
authors.initials: A
authors.lastname: Bast
authors.forename: Guido R M M
authors.initials: GR
authors.lastname: Haenen
authors.forename: Marc A J G
authors.initials: MA
authors.lastname: Fischer
authors.forename: Ger J
authors.initials: GJ
authors.lastname: van der Vusse
authors.forename: Emiel F M
authors.initials: EF
authors.lastname: Wouters
authors.forename: Annemie M W J
authors.initials: AM
authors.lastname: Schols
mesh_terms: D000368:Aged; D000975:Antioxidants / Q000378:metabolism*; D001823:Body Composition; D017079:Exercise Tolerance; D005260:Female; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D015227:Lipid Peroxidation; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000201:enzymology / Q000378:metabolism* / Q000503:physiopathology; D018384:Oxidative Stress; D029424:Pulmonary Disease, Chronic Obstructive / Q000201:enzymology / Q000378:metabolism* / Q000503:physiopathology; D014810:Vitamin E / Q000378:metabolism
chemical_list: D000975:Antioxidants; D014810:Vitamin E; D005982:Glutathione Transferase