Ghrelin (human)

Human ghrelin (GHR), the endogenous ligand of the growth hormone secretagogue receptor (GHS-R), potently stimulates GH release. The Ser³ octanoyl ester turned out to be essential for generating this activity. Ghrelin plays an important role in the short-time regulation of appetite and in the long-time regulation of energy balance and glucose homeostasis. A number of studies showed that ghrelin is also involved in the regulation of gastrointestinal, cardiovascular, and immune functions as well as in bone metabolism.