RESUMO
Physical exercise is a therapeutic strategy for some systemic and non-systemic complications. Various processes or factors like myokines are involved in an exercise course. Irisin is produced in skeletal muscle during exercise, and its effects resemble many exercise effects. Besides the systemic effects of muscle-derived irisin, this peptide is produced in different tissues. Numerous studies have investigated the underlying molecular mechanisms of irisin effects. Despite some controversies, most studies have demonstrated the improvement of metabolic-related complications and immunomodulatory or regenerative mechanisms in correlation with the circulating level of this peptide or after in vivo/in vitro treatments that have introduced it as a peptide with therapeutic value. This review describes the similarities and differences of the effects in various tissues and their correlation with the most prevalent tissue-related complication to present a view for the mechanism(s) of function, efficacy, and safety of this peptide in each tissue as an exercise effector and endocrine peptide.