Myokine

A myokine is a term referring to a cytokine which is produced from a muscle cell. Cytokines are a diverse and ill defined group of small proteins or proteoglycans. These intercellular communication molecules fulfill very diverse roles in regulation of cellular expression and differentiation whose systemic effects occur at mere picomolar concentrations. Of particular interest are their effects in immunomodulation and embryogenesis. IL-6 is the first myokine to appear in the circulation during exercise.