title: Muscle cytokine mRNA changes after 2.5 h of cycling: influence of carbohydrate.
abstract: OBJECTIVE
  To study the effect of carbohydrate compared to placebo ingestion on plasma cytokines and muscle cytokine mRNA following 2.5 h of intensive cycling in 15 trained cyclists.
  
  
  METHODS
  Fifteen trained cyclists cycled for 2.5 h at 60% Wmax on two occasions while receiving 4 mL.kg.15 min carbohydrate (6%) (CHO) or placebo (PLA) beverages in a randomized, counterbalanced design. Blood and vastus lateralis muscle biopsy samples were collected before and after exercise and 12 h postexercise and compared to samples taken from five cyclists who rested in the lab during the exercise sessions. Blood cell counts were determined, and plasma was analyzed for interleukin (IL)-6, IL-10, IL-1 receptor antagonist (ra), IL-8, cortisol, epinephrine, glucose, and insulin. Muscle was analyzed for glycogen content and relative gene expression of four cytokines, IL-6, IL-8, tumor necrosis factor (TNF) alpha, and IL-1beta, using real-time quantitative reverse transcriptase polymerase chain reaction.
  
  
  RESULTS
  Plasma glucose and insulin were higher, and epinephrine, cortisol, IL-6, IL-10, and IL-1ra, but not IL-8, were significantly lower postexercise in CHO versus PLA. Muscle glycogen content decreased 68% immediately postexercise and the pattern of change did not differ between CHO and PLA. Muscle IL-6, IL-8, TNF-alpha, but not IL-1beta mRNA increased immediately postexercise compared to controls, with no differences between CHO and PLA.
  
  
  CONCLUSIONS
  CHO compared to PLA beverage ingestion attenuated the increase in plasma cortisol, epinephrine, IL-6, IL-10, and IL-1ra, but not muscle IL-6, IL-8, and TNF-alpha mRNA in athletes cycling 2.5 h at 60% Wmax.
authors.affiliation: Department of Health, Leisure, and Exercise Science, Fischer Hamilton/Nycom Biochemistry Laboratory, Appalachian State University, Boone, NC 28608, USA. niemandc@appstate.edu
authors.forename: David C
authors.initials: DC
authors.lastname: Nieman
authors.forename: J Mark
authors.initials: JM
authors.lastname: Davis
authors.forename: Dru A
authors.initials: DA
authors.lastname: Henson
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Gross
authors.forename: Charles L
authors.initials: CL
authors.lastname: Dumke
authors.forename: Alan C
authors.initials: AC
authors.lastname: Utter
authors.forename: Debra M
authors.initials: DM
authors.lastname: Vinci
authors.forename: James A
authors.initials: JA
authors.lastname: Carson
authors.forename: Adrienne
authors.initials: A
authors.lastname: Brown
authors.forename: Steve R
authors.initials: SR
authors.lastname: McAnulty
authors.forename: Lisa S
authors.initials: LS
authors.lastname: McAnulty
authors.forename: N Travis
authors.initials: NT
authors.lastname: Triplett
mesh_terms: D001642:Bicycling; D001772:Blood Cell Count; D016207:Cytokines / Q000097:blood / Q000235:genetics* / Q000378:metabolism; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D002149:Energy Intake; D006003:Glycogen / Q000378:metabolism; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007328:Insulin / Q000097:blood; D018482:Muscle, Skeletal / Q000378:metabolism*; D009657:North Carolina; D010919:Placebos; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D016207:Cytokines; D004040:Dietary Carbohydrates; D007328:Insulin; D010919:Placebos; D012333:RNA, Messenger; D006003:Glycogen; D006854:Hydrocortisone