title: Time course of responses of human skeletal muscle to oxidative stress induced by nondamaging exercise.
abstract: Previous studies in animals have demonstrated that a single period of aerobic exercise induces a rise in the skeletal muscle activity of the antioxidant enzymes superoxide dismutase and catalase and an increase in the muscle content of heat shock proteins (HSPs). The purpose of this study was to examine the time course of response of human skeletal muscle superoxide dismutase and catalase activities and the content of HSP60 and HSP70 after a period of exhaustive, nondamaging aerobic exercise. Seven volunteers undertook one-legged cycle ergometry at 70% maximal oxygen uptake for 45 min. Biopsies were obtained from the vastus lateralis muscle 7 days before and at 1, 2, 3, and 6 days after exercise. Muscle superoxide dismutase activity increased to a peak at 3 days postexercise, muscle catalase activities were unchanged, and muscle content of HSP60 and the inducible HSP70 increased by variable amounts to reach means of 190% and 3,100% of preexercise values, respectively, by 6 days postexercise. These data indicate that human skeletal muscle responds to a single bout of nondamaging exercise by increasing superoxide dismutase activity and provide the first evidence of an increase in HSP content of human skeletal muscle after a submaximal exercise bout.
authors.affiliation: Department of Medicine, University of Liverpool, Liverpool L69 3GA, United Kingdom.
authors.forename: M
authors.initials: M
authors.lastname: Khassaf
authors.forename: R B
authors.initials: RB
authors.lastname: Child
authors.forename: A
authors.initials: A
authors.lastname: McArdle
authors.forename: D A
authors.initials: DA
authors.lastname: Brodie
authors.forename: C
authors.initials: C
authors.lastname: Esanu
authors.forename: M J
authors.initials: MJ
authors.lastname: Jackson
mesh_terms: D000328:Adult; D000332:Aerobiosis; D001706:Biopsy; D002374:Catalase / Q000378:metabolism*; D018834:Chaperonin 60 / Q000378:metabolism; D015444:Exercise / Q000502:physiology*; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D006339:Heart Rate; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism / Q000502:physiology*; D018384:Oxidative Stress / Q000502:physiology*; D010101:Oxygen Consumption; D005082:Physical Exertion / Q000502:physiology; D013482:Superoxide Dismutase / Q000378:metabolism*; D013997:Time Factors
chemical_list: D018834:Chaperonin 60; D018840:HSP70 Heat-Shock Proteins; D002374:Catalase; D013482:Superoxide Dismutase