title: Changes in serum cytokines after repeated bouts of downhill running.
abstract: The purpose of this study was to examine changes in serum cytokines after repeated bouts of aerobically biased eccentric exercise. Six untrained males ran down a -13.5% treadmill grade for 60 min on two occasions (RUN1 and RUN2) at a speed equal to 75% of their VO2 peak on a level grade; runs were spaced 14 d apart. Serum was collected before, after, and every hour for 12 h, and every 24 h for 6 d. Cytokines were assessed using 17 multiplex bead technology (Bio-Rad). Creatine kinase (CK) and delayed-onset muscle soreness (DOMS) were assessed before and 24-120 h after. Results were analyzed using a repeated measures analysis of variance (p <or= 0.05). All comparisons were between RUN1 and RUN2. CK and DOMS were significantly elevated after RUN1 compared with RUN2, indicative of a repeated bout effect. Regarding cytokines, during the initial 12 h period after RUN2, there was a 50% decrease in pro-inflammatory interleukin-6 (IL-6), a 10% decrease in pro-inflammatory macrophage chemotactic protein-1, and a 95% elevation in anti-inflammatory interleukin-10 (IL-10). Regarding 24 h periods, after RUN2 there was an 8% reduction in pro-inflammatory interleukin-8 (IL-8). However, pro-inflammatory macrophage inflammatory factor-1beta (MIF-1beta) was 18% higher during the 12 h after RUN2. The overall cytokine profile suggests a slight reduction in systemic inflammation after RUN2.
authors.affiliation: Department of Sport and Physical Rehabilitation Sciences, Tshwane University of Technology, Pretoria 0001, South Africa. smithll@tut.ac.za
authors.forename: Lucille L
authors.initials: LL
authors.lastname: Smith
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: McKune
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Semple
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Sibanda
authors.forename: Helen
authors.initials: H
authors.lastname: Steel
authors.forename: Ronald
authors.initials: R
authors.lastname: Anderson
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D016207:Cytokines / Q000097:blood*; D006801:Humans; D008297:Male; D012420:Running / Q000502:physiology*; D013997:Time Factors
chemical_list: D016207:Cytokines