title: Effect of glutamine supplementation on exercise-induced changes in lymphocyte function.
abstract: The purpose of this study was to investigate the possible role of glutamine in exercise-induced impairment of lymphocyte function. Ten male athletes participated in a randomized, placebo-controlled, double-blind crossover study. Each athlete performed bicycle exercise for 2 h at 75% of maximum O(2) consumption on 2 separate days. Glutamine or placebo supplements were given orally during and up to 2 h postexercise. The trial induced postexercise neutrocytosis that lasted at least 2 h. The total lymphocyte count increased by the end of exercise due to increase of both CD3(+)TCR alpha beta(+) and CD3(+)TCR gamma delta(+) T cells as well as CD3(-)CD16(+)CD56(+) natural killer (NK) cells. Concentrations of CD8(+) and CD4(+) T cells lacking CD28 and CD95 on their surface increased more than those of cells expressing these receptors. Within the CD4(+) cells, only CD45RA(-) memory cells, but not CD45RA(+) naive cells, increased in response to exercise. Most lymphocyte subpopulations decreased 2 h after exercise. Glutamine supplementation abolished the postexercise decline in plasma glutamine concentration but had no effect on lymphocyte trafficking, NK and lymphokine-activated killer cell activities, T cell proliferation, catecholamines, growth hormone, insulin, or glucose. Neutrocytosis was less pronounced in the glutamine-supplemented group, but it is unlikely that this finding is of any clinical significance. This study does not support the idea that glutamine plays a mechanistic role in exercise-induced immune changes.
authors.affiliation: Copenhagen Muscle Research Centre and Department of Infectious Diseases, Rigshospitalet, 2200 Copenhagen N, Denmark.
authors.forename: K
authors.initials: K
authors.lastname: Krzywkowski
authors.forename: E W
authors.initials: EW
authors.lastname: Petersen
authors.forename: K
authors.initials: K
authors.lastname: Ostrowski
authors.forename: J H
authors.initials: JH
authors.lastname: Kristensen
authors.forename: J
authors.initials: J
authors.lastname: Boza
authors.forename: B K
authors.initials: BK
authors.lastname: Pedersen
mesh_terms: D000328:Adult; D001786:Blood Glucose; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D002455:Cell Division / Q000187:drug effects; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004837:Epinephrine / Q000097:blood; D015444:Exercise / Q000502:physiology*; D005973:Glutamine / Q000008:administration & dosage*; D019382:Human Growth Hormone / Q000097:blood; D006801:Humans; D007328:Insulin / Q000097:blood; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology; D018655:Lymphocyte Count; D008214:Lymphocytes / Q000187:drug effects* / Q000276:immunology; D008875:Middle Aged; D009000:Monocytes / Q000166:cytology; D009504:Neutrophils / Q000166:cytology; D009638:Norepinephrine / Q000097:blood
chemical_list: D001786:Blood Glucose; D007328:Insulin; D005973:Glutamine; D019382:Human Growth Hormone; D009638:Norepinephrine; D004837:Epinephrine