IL-6 and TNF-alpha expression in, and release from, contracting human skeletal muscle

• Published in: American journal of physiology: endocrinology and metabolism Vol. 283; no. 6; pp. E1272 - E1278
• Main Authors: Steensberg, Adam, Keller, Charlotte, Starkie, Rebecca L, Osada, Takuya, Febbraio, Mark A, Pedersen, Bente Klarlund
• Format: Journal Article
• Language: English
• Published: United States 01.12.2002
• Subjects: Adult; Blood Glucose - analysis; Exercise Test; Fatty Acids, Nonesterified - blood; Femoral Artery - physiology; Femoral Vein - physiology; Glycogen - analysis; Glycogen - metabolism; Humans; Interleukin-6 - genetics; Interleukin-6 - metabolism; Interleukin-6 - secretion; Leg - blood supply; Leg - physiology; Male; Muscle Contraction - physiology; Muscle, Skeletal - chemistry; Muscle, Skeletal - metabolism; Muscle, Skeletal - secretion; Physical Exertion - physiology; Reference Values; Regional Blood Flow; RNA, Messenger - analysis; RNA, Messenger - metabolism; Tumor Necrosis Factor-alpha - genetics; Tumor Necrosis Factor-alpha - metabolism; Tumor Necrosis Factor-alpha - secretion
• ISSN: 0193-1849; 1522-1555
• DOI: 10.1152/ajpendo.00255.2002

1  Copenhagen Muscle Research Centre and 2  Department of Infectious Diseases, Rigshospitalet, University of Copenhagen, DK-2100 Copenhagen, Denmark; and 3  Department of Physiology, The University of Melbourne, Parkville, Victoria xxxx, Australia The aim of the present study was to examine whether IL-6 and TNF- are expressed in, and released from, human skeletal muscle during exercise. We hypothesized that the skeletal muscle will release IL-6, but not TNF- , during exercise because of previous observations that TNF- negatively affects glucose uptake in skeletal muscle. Six healthy, male subjects performed 180 min of two-legged knee-extensor exercise. Muscle samples were obtained from the vastus lateralis of one limb. In addition, blood samples were obtained from a femoral artery and vein. Plasma was analyzed for IL-6 and TNF- . We detected both IL-6 and TNF- mRNA in resting muscle samples, and whereas IL-6 increased ( P  < 0.05) ~100-fold throughout exercise, no significant increase in TNF- mRNA was observed. Arterial plasma TNF- did not increase during exercise. Furthermore, there was no net release of TNF- either before or during exercise. In contrast, IL-6 increased throughout exercise in arterial plasma, and a net IL-6 release from the contracting limb was observed after 120 min of exercise ( P  < 0.05). cytokines; interleukins; exercise; metabolism; endocrine system