We have identified the skeletal muscle as an endocrine organ, which by contraction stimulates the production and release of cytokines (myokines), which can influence metabolism and modify cytokine production in tissue and organs.
Given the fact that during contraction skeletal muscle cells undergo a major disruption to cellular quiescence, we hypothesize that muscle cells release a number of biologically active substances that we term myokines, which participate in cell to cell and organ to organ cross-talk. Myokines may be involved in mediating the health beneficial effects of exercise and play important roles in the protection against diseases associated with low-grade inflammation, insulin resistance, hyperlipidemia such as cardiovascular diseases, type 2 diabetes, and cancer.
Knowledge about the mechanisms whereby regular exercise offers protection against chronic diseases in combination with clinical research serves as a foundation for the development of public health recommendations with regard to exercise. The identification of new myokines and their receptors will potentially serve as pharmacological targets for the treatment of metabolic disorders and other diseases.