Premium
Calprotectin is released from human skeletal muscle tissue during exercise
Author(s) -
Mortensen Ole Hartvig,
Andersen Kasper,
Fischer Christian,
Nielsen Anders Rinnov,
Nielsen Søren,
Åkerström Thorbjörn,
Aastrøm Majbrit,
Borup Rehannah,
Pedersen Bente Klarlund
Publication year - 2008
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2008.153551
Subject(s) - skeletal muscle , calprotectin , s100a8 , medicine , endocrinology , s100a9 , gastrocnemius muscle , inflammation , disease , inflammatory bowel disease
Skeletal muscle has been identified as a secretory organ. We hypothesized that IL‐6, a cytokine secreted from skeletal muscle during exercise, could induce production of other secreted factors in skeletal muscle. IL‐6 was infused for 3 h into healthy young males ( n = 7) and muscle biopsies obtained at time points 0, 3 and 6 h in these individuals and in resting controls. Affymetrix microarray analysis of gene expression changes in skeletal muscle biopsies identified a small set of genes changed by IL‐6 infusion. RT‐PCR validation confirmed that S100A8 and S100A9 mRNA were up‐regulated 3‐fold in skeletal muscle following IL‐6 infusion compared to controls. Furthermore, S100A8 and S100A9 mRNA levels were up‐regulated 5‐fold in human skeletal muscle following cycle ergometer exercise for 3 h at ∼60% of in young healthy males ( n = 8). S100A8 and S100A9 form calprotectin, which is known as an acute phase reactant. Plasma calprotectin increased 5‐fold following acute cycle ergometer exercise in humans, but not following IL‐6 infusion. To identify the source of calprotectin, healthy males ( n = 7) performed two‐legged dynamic knee extensor exercise for 3 h with a work load of ∼50% of peak power output and arterial–femoral venous differences were obtained. Arterial plasma concentrations for calprotectin increased 2‐fold compared to rest and there was a net release of calprotectin from the working muscle. In conclusion, IL‐6 infusion and muscle contractions induce expression of S100A8 and S100A9 in skeletal muscle. However, IL‐6 alone is not a sufficient stimulus to facilitate release of calprotectin from skeletal muscle.