%0 Journal Article %J Clinical Chemistry and Laboratory Medicine %D 2009 %T Systemic cytokine response following exercise-induced muscle damage in humans %A Philippou, A.a %A Bogdanis, G.b %A Maridaki, M.b %A Halapas, A.a %A Sourla, A.c %A Koutsilieris, M.a %X Background: Muscle adaptation which occurs following eccentric exercise-induced muscle damage has been associated with an acute inflammatory response. The purpose of this study was to investigate serum interleukin-6 (IL-6), osteoprotegerin and receptor activator of nuclear factor kB ligand (OPG/RANKL) concentrations following muscle damage. We measured changes for several days following muscle damage. Methods: Ten healthy young males performed an eccentric exercise protocol using their quadriceps. Blood samples were withdrawn before and at 6 h, 2 days, 5 days and 16 days post-exercise. Functional and clinical measurements were performed before, and on days 1, 2, 5, 8, 12 and 16 post-exercise. Results: The exercise protocol resulted in muscle damage, indicated by changes in biochemical markers. An increase in IL-6 and OPG, and a decrease in RANKL concentrations were seen at 6 h and on day 2 post-exercise; the OPG:RANKL ratio was increased at 6 h post-exercise (p<0.05). Conclusions: Changes in IL-6 and OPG/RANKL system may represent systemic responses in muscle inflammation and repair processes. However, further studies are needed to elucidate a potential systemic and/or local role of the OPG/RANKL system in skeletal muscle repair. © 2009 by Walter de Gruyter. %B Clinical Chemistry and Laboratory Medicine %V 47 %P 777-782 %G eng %U https://www.scopus.com/inward/record.url?eid=2-s2.0-67650600623&partnerID=40&md5=a2b7c28d2796227f2c2d0c905f8b58a7 %R 10.1515/CCLM.2009.163