title: Prolonged submaximal eccentric exercise is associated with increased levels of plasma IL-6.
abstract: To study the relationship between exercise-related muscle proteolysis and the cytokine response, a prolonged eccentric exercise model of one leg was used. Subjects performed two trials [a branched-chain amino acid (BCAA) supplementation and a control trial]. The release of amino acids from muscle during and after the eccentric exercise was decreased in the BCAA trial, suggesting a suppression of net muscle protein degradation. The plasma concentrations of interleukin (IL)-6 increased from 0.75 +/- 0.19 (preexercise) to 5.02 +/- 0.96 pg/ml (2 h postexercise) in the control trial and in the BCAA supplementation trial from 1.07 +/- 0.41 to 4.15 +/- 1.21 pg/ml. Eccentric exercise had no effect on the concentrations of neutrophils, lymphocytes, CD16+/CD56+, CD4+, CD8+, CD14+/CD38+, lymphocyte proliferative response, or cytotoxic activities. BCAA supplementation reduced the concentration of CD14+/CD38+ cells. This study shows that the concentration of IL-6 in plasma is increased after prolonged eccentric exercise and suggests that the cytokine response is independent of the muscle proteolysis that occur during exercise.
authors.affiliation: Copenhagen Muscle Research Centre, Department of Infectious Diseases, Rigshospitalet, Copenhagen N, Denmark.
authors.forename: T
authors.initials: T
authors.lastname: Rohde
authors.forename: D A
authors.initials: DA
authors.lastname: MacLean
authors.forename: E A
authors.initials: EA
authors.lastname: Richter
authors.forename: B
authors.initials: B
authors.lastname: Kiens
authors.forename: B K
authors.initials: BK
authors.lastname: Pedersen
mesh_terms: D000328:Adult; D000596:Amino Acids / Q000097:blood; D000597:Amino Acids, Branched-Chain / Q000494:pharmacology*; D000704:Analysis of Variance; D016207:Cytokines / Q000097:blood*; D004837:Epinephrine / Q000097:blood; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005527:Food, Fortified; D006801:Humans; D007375:Interleukin-1 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood*; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology*; D007958:Leukocyte Count; D008213:Lymphocyte Activation; D018655:Lymphocyte Count; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D009638:Norepinephrine / Q000097:blood; D012016:Reference Values; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000596:Amino Acids; D000597:Amino Acids, Branched-Chain; D016207:Cytokines; D007375:Interleukin-1; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D009638:Norepinephrine; D004837:Epinephrine