| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 The Centre of Inflammation and Metabolism at Department of Infectious Diseases and Copenhagen Muscle Research Center, Rigshospitalet and Faculty of Health Sciences, University of Copenhagen, Denmark 2 Section of Neuroprotection, Institute of Neurobiology and Molecular Pharmacology, Faculty of Health Sciences, University of Copenhagen, Denmark
Exercise induces a marked increase in interleukin-8 (IL-8) mRNA and protein expression within skeletal muscle fibres. Interleukin-8 belongs to a subfamily of CXC chemokines containing a Glu-Leu-Arg (ELR) motif. CXC chemokines with ELR motifs are potent angiogenic factors in vivo, and IL-8 has been shown to act as an angiogenic factor in human microvascular endothelial cells by binding to the CXC receptor 2 (CXCR2). In the present study, we examined the expression of the interleukin-8 receptor CXCR2 in human skeletal muscle biopsies after concentric exercise. Healthy volunteers were randomized to either 3 h of cycle ergometer exercise at 60% of maximum oxygen uptake (n = 8) or rest (n = 7). Muscle biopsy samples were obtained from the vastus lateralis before exercise (0 h), immediately after exercise (3 h), and at 4.5, 6, 9 and 24 h. Skeletal muscle CXCR2 mRNA increased significantly in response to exercise (3 and 4.5 h) when compared with pre-exercise samples. Expression of the CXCR2 protein was low in skeletal muscle biopsies before exercise and at the end of the exercise period (3 h). However, at 4.5–9 h, an increase in CXCR2 protein was seen in the vascular endothelium, and also slightly within the muscle fibres, as determined by immunohistochemistry. The present study demonstrates that concentric exercise induces CXCR2 mRNA and protein expression in the vascular endothelial cells of the muscle fibres. These findings suggest that muscle-derived IL-8 may act locally to stimulate angiogenesis through CXCR2 receptor signalling.
(Received 9 July 2006;
accepted after revision 5 October 2006; first published online 9 October 2006)
Corresponding author B. K. Pedersen: Centre of Inflammation and Metabolism, Rigshospitalet – Section 7641, Blegdamsvej 9, DK-2100, Copenhagen, Denmark. Email: bkp{at}rh.dk
This article has been cited by other articles:
|
|
 |
|
  S. C. Nance, A.-K. Yi, F. C. Re, and E. A. Fitzpatrick MyD88 is necessary for neutrophil recruitment in hypersensitivity pneumonitis J. Leukoc. Biol., May 1, 2008; 83(5): 1207 - 1217. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Broholm, O. H. Mortensen, S. Nielsen, T. Akerstrom, A. Zankari, B. Dahl, and B. K. Pedersen Exercise induces expression of leukaemia inhibitory factor in human skeletal muscle J. Physiol., April 15, 2008; 586(8): 2195 - 2201. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. C. Nieman, D. A. Henson, J. M. Davis, E. Angela Murphy, D. P. Jenkins, S. J. Gross, M. D. Carmichael, J. C. Quindry, C. L. Dumke, A. C. Utter, et al. Quercetin's influence on exercise-induced changes in plasma cytokines and muscle and leukocyte cytokine mRNA J Appl Physiol, November 1, 2007; 103(5): 1728 - 1735. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Louis, U. Raue, Y. Yang, B. Jemiolo, and S. Trappe Time course of proteolytic, cytokine, and myostatin gene expression after acute exercise in human skeletal muscle J Appl Physiol, November 1, 2007; 103(5): 1744 - 1751. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. K. Pedersen, T. C. A. Akerstrom, A. R. Nielsen, and C. P. Fischer Role of myokines in exercise and metabolism J Appl Physiol, September 1, 2007; 103(3): 1093 - 1098. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
