title: Fatiguing exercise reduces DNA binding activity of NF-kappaB in skeletal muscle nuclei.
abstract: This study tested the hypothesis that skeletal muscle contraction activates nuclear factor-kappaB (NF-kappaB), a putative regulator of muscle protein breakdown. Muscle biopsies were obtained from the vastus lateralis of healthy humans before, immediately after, and 1 h after fatiguing resistance exercise of the lower limbs. Biopsies were analyzed for nuclear NF-kappaB DNA binding activity by using electrophoretic mobility shift assay. NF-kappaB activity, measured immediately after exercise, was less than preexercise activity; after 1-h recovery, activity returned to preexercise levels. In follow-up studies in adult mice, basal NF-kappaB activity varied among individual muscles. NF-kappaB activity in diaphragm fiber bundles was decreased after a 10-min bout of fatiguing tetanic contractions in vitro. NF-kappaB activity in soleus was increased by 12 days of unloading by hindlimb suspension; this increase was reversed by 10 min of fatiguing exercise. These data provide no support for our original hypothesis. Instead, acute fatiguing exercise appears to decrease NF-kappaB activity in muscle under a variety of conditions.
authors.affiliation: Pulmonary and Critical Care Medicine Section, Baylor College of Medicine, Houston, Texas 77030, USA.
authors.forename: William J
authors.initials: WJ
authors.lastname: Durham
authors.forename: Yi-Ping
authors.initials: YP
authors.lastname: Li
authors.forename: Eric
authors.initials: E
authors.lastname: Gerken
authors.forename: Mehran
authors.initials: M
authors.lastname: Farid
authors.forename: Sandrine
authors.initials: S
authors.lastname: Arbogast
authors.forename: Robert R
authors.initials: RR
authors.lastname: Wolfe
authors.forename: Michael B
authors.initials: MB
authors.lastname: Reid
mesh_terms: D000328:Adult; D000818:Animals; D004247:DNA / Q000378:metabolism*; D003964:Diaphragm / Q000378:metabolism; D015444:Exercise / Q000502:physiology*; D005260:Female; D006614:Hindlimb; D019417:Hindlimb Suspension; D006801:Humans; D007866:Leg; D008099:Liver / Q000378:metabolism; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism*; D013997:Time Factors
chemical_list: D016328:NF-kappa B; D004247:DNA