title: Exercise-induced quadriceps oxidative stress and peripheral muscle dysfunction in patients with chronic obstructive pulmonary disease.
abstract: Exercise-induced muscle oxidative stress may be involved in the myopathy associated with chronic obstructive pulmonary disease (COPD). This study was designed to look at whether local exercise induces muscle oxidative stress and whether this oxidative stress may be associated with the reduced muscle endurance in patients with COPD. Quadriceps endurance was measured in 12 patients with COPD (FEV1 = 0.96 +/- 0.14 SEM) and 10 healthy sedentary subjects by repeated knee extensions of the dominant leg. Biopsies of the vastus lateralis muscle were obtained before and 48 hours after exercise. Muscle oxidative stress was measured by lipid peroxidation and oxidized proteins. Muscle antioxidant was evaluated by peroxidase glutathion activity. Quadriceps endurance was significantly reduced in patients with COPD when compared with the healthy control subjects (p < 0.01). Forty-eight hours postexercise, only patients with COPD had a significant increase in muscle lipid peroxidation (p < 0.05) and oxidized proteins (p < 0.05), whereas increased peroxidase glutathion activity was only observed in control subjects (p < 0.05). Both increases in muscle lipid peroxidation and oxidized proteins were significantly and inversely correlated with quadriceps endurance capacity in COPD (p < 0.05). In summary, local exercise induced muscle oxidative stress in patients with COPD, whereas it failed to raise antioxidant activity. In these individuals, muscle oxidative stress was associated with a reduced quadriceps endurance.
authors.affiliation: UPRES-EA 701, Laboratory of Physiologie des Interactions, Service Central de Physiologie Clinique, Hôpital Arnaud de Villeneuve, 34295 Montpellier cedex 5, France. annabelle_couillard@yahoo.fr
authors.forename: Annabelle
authors.initials: A
authors.lastname: Couillard
authors.forename: François
authors.initials: F
authors.lastname: Maltais
authors.forename: Didier
authors.initials: D
authors.lastname: Saey
authors.forename: Richard
authors.initials: R
authors.lastname: Debigaré
authors.forename: Annie
authors.initials: A
authors.lastname: Michaud
authors.forename: Christelle
authors.initials: C
authors.lastname: Koechlin
authors.forename: Pierre
authors.initials: P
authors.lastname: LeBlanc
authors.forename: Christian
authors.initials: C
authors.lastname: Préfaut
mesh_terms: D000368:Aged; D000886:Anthropometry; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D001706:Biopsy; D016022:Case-Control Studies; D003402:Creatine Kinase / Q000097:blood; D005541:Forced Expiratory Volume; D005979:Glutathione Peroxidase / Q000032:analysis; D006801:Humans; D015151:Immunoblotting; D015227:Lipid Peroxidation; D008297:Male; D018908:Muscle Weakness / Q000209:etiology* / Q000378:metabolism* / Q000473:pathology; D018482:Muscle, Skeletal / Q000737:chemistry / Q000378:metabolism*; D018384:Oxidative Stress; D010807:Physical Endurance; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications*; D012146:Rest; D012907:Smoking / Q000009:adverse effects; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis; D013997:Time Factors; D014797:Vital Capacity
chemical_list: D015415:Biomarkers; D017392:Thiobarbituric Acid Reactive Substances; D005979:Glutathione Peroxidase; D003402:Creatine Kinase