title: Glutamine preserves skeletal muscle force during an inflammatory insult.
abstract: The purpose of this study was to test the hypothesis that acute glutamine (GLN) supplementation can counteract skeletal muscle contractile dysfunction occurring in response to inflammation by elevating muscle heat shock protein (Hsp) expression and reducing inflammatory cytokines. Mice received 5 mg/kg lipopolysaccharide (LPS) concurrently with 1 g/kg GLN or vehicle treatments. Plantarflexor isometric force production was measured at 2 hours post-injection. Blood and gastrocnemius muscles were collected, and serum and muscle tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) and muscle Hsp70 and Hsp25 were quantified. Saline/LPS treatment was associated with a 33% reduction in maximal force and elevated serum TNF-alpha and IL-6. GLN completely prevented this force decrement with LPS. GLN was found to reduce muscle Hsp70 and IL-6, but only in the presence of LPS. GLN supplementation provides an effective, novel, clinically applicable means of preserving muscle force during acute inflammation. These data indicate that force preservation is not dependent on reductions in serum cytokines or muscle TNF-alpha, or elevated Hsp levels.
authors.affiliation: Department of Kinesiology, University of Illinois at Urbana-Champaign, 120 Freer Hall, 906 South Goodwin Avenue, Urbana, Illinois 61801, USA. bmeador@uiuc.edu
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Meador
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Huey
mesh_terms: D000818:Animals; D005973:Glutamine / Q000008:administration & dosage*; D050884:HSP72 Heat-Shock Proteins / Q000097:blood / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000097:blood / Q000378:metabolism; D007249:Inflammation / Q000150:complications*; D015850:Interleukin-6 / Q000097:blood / Q000378:metabolism; D008070:Lipopolysaccharides; D051379:Mice; D018832:Molecular Chaperones; D009119:Muscle Contraction / Q000187:drug effects*; D018908:Muscle Weakness / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D009363:Neoplasm Proteins / Q000097:blood / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000097:blood / Q000378:metabolism
chemical_list: D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins; C486113:Hsbp1 protein, mouse; D015850:Interleukin-6; D008070:Lipopolysaccharides; D018832:Molecular Chaperones; D009363:Neoplasm Proteins; D014409:Tumor Necrosis Factor-alpha; D005973:Glutamine