Systemic cytokine response following exercise-induced muscle damage in humans

Abstract

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 Blood samples were withdrawn before and at 6 h, 2 days, 5 days and 16 days post-exercise.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. Clin Chem Lab Med 2009;47:777-82.

Effect of elastic-band exercise on muscle damage and inflammatory responses in Taekwondo athletes

“…In our study, IL-6 increased only immediate after exercise and at a lesser extent compared other study on eccentric exercise 12 , which is probably related to the smaller of muscle damage induced by elastic-band exercise as compared with other exercise models. This was indicated by the increase in serum IL-6 concentrations within hour's post-exercise, corroborating previously published data 7,9,24 . The early increase in serum IL-6 post eccentric exercise-induced muscle damage has been assumed to originate from inflammatory cells infiltrating damaged skeletal muscle 9 .…”

“…This was indicated by the increase in serum IL-6 concentrations within hour's post-exercise, corroborating previously published data 7,9,24 . The early increase in serum IL-6 post eccentric exercise-induced muscle damage has been assumed to originate from inflammatory cells infiltrating damaged skeletal muscle 9 .…”

“…Exercise-induced muscle damage has been associated with disruption of the normal myofilamentm structures in sarcomeres 7 , damage to sarcolemma, loss of fiber integrity and leakage of muscle-specific enzymes and proteins into the blood, acute inflammatory response 8 , delayed-onset muscle soreness and loss of muscle contraction force 9 .…”

“…Cytokines may be produced by a variety of cells including endothelial cells, tissue-resident leukocytes and circulating leukocytes 11 . They contribute to specific aspects of acute inflammation and may be characterized as either pro-or anti-inflammatory, based on their predominant action 9 .…”

Separation of Fast from Slow Anabolism by Site-specific PEGylation of Insulin-like Growth Factor I (IGF-I)

“…These trials included treatment of insulin resistance, diabetes, and growth disorders (7), cardiovascular diseases (8), and stroke (9). For skeletal muscle conditions, similar approaches have been proposed (10) and preclinical proof of concept has been shown for attenuation of muscular deterioration after subchronic rhIGF-I therapy (11). However, dosing limitations have precluded its clinical development in these indications.…”