title: Eccentric muscle contractions induce greater oxidative stress than concentric contractions in skeletal muscle.
abstract: The purpose of this study was to examine oxidative stress in skeletal muscle after eccentric and concentric muscle contractions. Eight-week-old Institute of Cancer Research (ICR) mice (n = 90) were divided into 3 groups: eccentric muscle contraction group (ECC, n = 42), concentric muscle contraction group (CON, n = 42), and control group (pre, n = 6). The tibialis anterior muscle was stimulated via the peroneal nerve to contract either eccentrically or concentrically. The tibialis anterior muscle was isolated before and 0, 6, 12, 18, 24, 72, and 168 h after muscle contraction. Immediately after muscle contractions, thiobarbituric acid reactive substances (TBARS) in skeletal muscle significantly increased (p < 0.05) in both ECC and CON conditions. However, in the ECC group alone, the TBARS level peaked at 12 and 72 h after the contractions. There was greater migration of mononuclear cells in ECC than in CON muscle. In addition, there was a correlation between TBARS in skeletal muscle and migration of mononuclear cells in ECC muscle (r = 0.773, p < 0.01), but this correlation was not apparent in CON muscle (r = 0.324, p = 0.12). The increased mononuclear cells may reflect inflammatory cells. These data suggest that eccentric muscle contraction induces greater oxidative stress in skeletal muscle, which may in turn be due to enhanced generation of reactive oxygen species (ROS) by migrating inflammatory cells.
authors.affiliation: Graduate School of Comprehensive Human Sciences, Doctoral program of Sports Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8574, Japan.
authors.forename: Michihiro
authors.initials: M
authors.lastname: Kon
authors.forename: Kai
authors.initials: K
authors.lastname: Tanabe
authors.forename: Hoseong
authors.initials: H
authors.lastname: Lee
authors.forename: Fuminori
authors.initials: F
authors.lastname: Kimura
authors.forename: Takayuki
authors.initials: T
authors.lastname: Akimoto
authors.forename: Ichiro
authors.initials: I
authors.lastname: Kono
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D006614:Hindlimb; D007962:Leukocytes / Q000166:cytology; D051379:Mice; D008813:Mice, Inbred ICR; D032342:Muscle Cells / Q000473:pathology; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000293:injuries* / Q000473:pathology; D018384:Oxidative Stress / Q000502:physiology*; D017382:Reactive Oxygen Species; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism*
chemical_list: D017382:Reactive Oxygen Species; D017392:Thiobarbituric Acid Reactive Substances