Muscle as a paracrine and endocrine organ

Abstract

Skeletal muscle cells are highly abundant and metabolically active and are known to 'communicate' their energy demands to other organs through active secretion. Muscle-derived secretory proteins include a variety of cytokines and peptides collectively referred to as 'myokines' that exert autocrine, paracrine or endocrine effects. Analyses of the skeletal muscle secretome revealed that numerous myokines are secreted in response to contraction or strength training, and that these factors not only regulate energy demand but also contribute to the broad beneficial effects of exercise on cardiovascular, metabolic, and mental health. Herein we review recent studies on the myokines that regulate muscle function and those that mediate cross talk between skeletal muscle and other organs including adipose tissue, liver, pancreas, the cardiovascular system, brain, bones, and skin.

Figure 1. Skeletal muscle as a paracrine and endocrine organ

Skeletal muscle is one of the largest tissues in the body and myofibers are one of the most metabolically active tissues. Skeletal muscles ‘communicate’ their energy demands to other organs through active release of factors. Muscle-derived secretory proteins include a variety of cytokines and peptides collectively termed “myokines” that exert auto-, para- or endocrine effects.