title: Circulating levels of peripheral blood leucocytes and cytokines following competitive cycling.
abstract: The objective of the study was to determine if prolonged and strenuous cycling leads to a polarized cytokine response, and/or unique mobilization of circulating leucocyte populations. Resting venous blood samples were collected from 6 amateur cyclists, 24 hr before, and at 10-25 min and 150 min after completion of a 250-km road race (race time: 404 +/- 3.5 min). Total leucocyte counts were significantly elevated following competition. Cell counts of CD3+CD8bright+ lymphocytes were depressed by 50% 150 min after competition. A significant increase in CD4+ cells expressing the IL-2R alpha chain was evident 150 min after competition. IL-6 concentrations were greatly increased, both at 10-25 min and 150 min after competition. Resting TNF-a concentrations were approximately doubled at both time points after competition. Plasma levels of IFN-gamma, IL-10 and IL-12 were below detection thresholds at all time points. These results suggest that performance of a 6.5 h competitive cycle-race does not induce a Type-1 or Type-2-dominated cytokine response, but one that is typical of a proinflammatory cytokine response.
authors.affiliation: Defence and Civil Institute of Environmental Medicine (DCIEM), Operational Medicine, North York, ON.
authors.forename: G A
authors.initials: GA
authors.lastname: Gannon
authors.forename: S G
authors.initials: SG
authors.lastname: Rhind
authors.forename: M
authors.initials: M
authors.lastname: Suzui
authors.forename: P N
authors.initials: PN
authors.lastname: Shek
authors.forename: R J
authors.initials: RJ
authors.lastname: Shephard
mesh_terms: D000328:Adult; D001642:Bicycling / Q000502:physiology*; D015704:CD4 Antigens / Q000097:blood; D016207:Cytokines / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D004906:Erythrocyte Count; D006801:Humans; D007962:Leukocytes / Q000166:cytology*; D008297:Male; D015375:Receptors, Interleukin-2 / Q000097:blood; D012016:Reference Values; D013312:Stress, Physiological / Q000097:blood* / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000166:cytology
chemical_list: D015704:CD4 Antigens; D016207:Cytokines; D015375:Receptors, Interleukin-2