Muscle‐derived interleukin‐6: possible biological effects

Abstract

Interleukin‐6 (IL‐6) is produced locally in working skeletal muscle and can account for the increase in plasma IL‐6 during exercise. The production of IL‐6 during exercise is related to the intensity and duration of the exercise, and low muscle glycogen content stimulates the production. Muscle‐derived IL‐6 is released into the circulation during exercise in high amounts and is likely to work in a hormone‐like fashion, exerting an effect on the liver and adipose tissue, thereby contributing to the maintenance of glucose homeostasis during exercise and mediating exercise‐induced lipolysis. Muscle‐derived IL‐6 may also work to inhibit the effects of pro‐inflammatory cytokines such as tumour necrosis factor α. The latter cytokine is produced by adipose tissue and inflammatory cells and appears to play a pathogenetic role in insulin resistance and atherogenesis.