IRISIN: A NEWLY DISCOVERED NOVEL MYOKINE

Abstract

The name irisin was given after the Greek messenger goddess Iris. It is secreted by muscles during exercise. Irisin enhances lipolysis and inhibits hepatic cholesterol synthesis. Acute exercise markedly increases irisin levels and is correlated mainly with ATP levels.

A positive correlation exists between plasma irisin and muscle mass, glucose, ghrelin, IGF1, and BMI. Plasma irisin levels are reduced markedly in patients with type 2 diabetes. Irisin levels are negatively associated with age, serum cholesterol, serum insulin, and serum adiponectin levels. Irisin induces the browning of subcutaneous white adipocytes. It increases aerobic capacity. In the liver, irisin promotes the synthesis of glycogen and inhibits gluconeogenesis. It may contribute to the beta cells profile ration. Irisin has an antioxidant effect. It induces endothelial angiogenesis.