Leptin is a cytokine 16 Kd peptide hormone .Its crucial role is regulation of appetite and the body fat mass mainly through action on the hypothalamus.
It is produced manily in adipocytes of white fat,as well as from other tissue ,e.g placenta ,skeletal muscles , fundus of the stomach and activated hepatic stellate cell (HSC). and recently reported that leptin is produced from B cell of islands of the pancreas.The gene responsible for production is present on chromosome 7 called obse gene(ob /gene).Leptin receptor (OB-R) were present in two forms short (OB-Ra or OB-RS) and long one (OB-Rb orOBRl).The main action of leptin depends on long form(OB-Rl),where very little evidence is available implicating a role for the short form in the action of leptin.One of the unconventional areas in which leptin is now receiving great attention is liver diseases as several published studies indicate that circulating leptin level are increased in cirrhosid , hepatitis C virus (HCV ) and non –alcoholic steatohepatitis (NASH).