Glucose ingestion during endurance training in men attenuates expression of myokine receptor

• Published in: Experimental physiology 2009-11, Vol.94 (11), p.1124-1131
• Main Authors: Akerstrom, Thorbjorn C. A., Krogh‐Madsen, Rikke, Petersen, Anne Marie Winther, Pedersen, Bente Klarlund
• Format: Article
• Language: English
• Subjects: Adaptation, Physiological - physiology; Adult; Bicycling - physiology; Blotting, Western; Glucose - pharmacology; Humans; Interleukin-6 - blood; Interleukin-6 Receptor alpha Subunit - biosynthesis; Interleukin-6 Receptor alpha Subunit - genetics; Male; Muscle, Skeletal - metabolism; Physical Endurance - physiology; Physical Fitness - physiology; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - biosynthesis; RNA, Messenger - genetics; Young Adult
• ISSN: 0958-0670; 1469-445X
• DOI: 10.1113/expphysiol.2009.048983

Glucose ingestion during exercise attenuates the release of the myokine interleukin-6 (IL-6) from working skeletal muscle, which results in a diminished increase in plasma IL-6. Interleukin-6 receptor α (IL-6Rα) expression in skeletal muscle is induced by acute exercise, mediated in part by an increased IL-6 concentration in the bloodstream. We hypothesized that endurance training would increase the density of IL-6Rα in skeletal muscle and that glucose ingestion would attenuate the effect. Nine subjects performed 10 weeks of one-legged knee-extensor training. They trained one leg (Glc-leg) while ingesting a glucose solution (Glc) and ingested a placebo (Plc) while training the other leg (Plc-leg). Endurance training increased peak power by ∼14% and reduced the exercise-induced gene expression of IL-6 and IL-6Rα in skeletal muscle and IL-6 plasma concentration. The IL-6Rα density increased to a lesser extent in the Glc-leg, suggesting that glucose ingestion attenuates the effect of training on IL-6Rα by blunting the IL-6 response. We conclude that glucose ingestion during endurance training attenuates the increase in IL-6Rα density.