Growth hormone secretagogue receptor Growth hormone secretagogue receptor Growth hormone secretagogue receptor(GHS-R), also known as ghrelin receptor, is a G protein-coupled receptor that binds growth hormone secretagogues (GHSs), such as ghrelin, the "hunger hormone". The role of GHS-R is thought to be in regulating energy homeostasis and body weight. In the brain, they are most highly expressed in the hypothalamus, specifically the ventromedial nucleus and arcuate nucleus. GSH-Rs are also expressed in other areas of the brain, including the ventral tegmental area, hippocampus, and substantia nigra. Outside the central nervous system, too, GSH-Rs are also found in the liver, in skeletal muscle, and even
Ghrelin promotilin and both are members of the motilin family. Unlike the case of many other endogenous peptides, ghrelin is able to cross the blood-brain-barrier, giving exogenously-administered ghrelin unique clinical potential. Ghrelin was discovered after the ghrelin receptor (called growth hormone secretagogue type 1A receptor or GHS-R) was discovered in 1996 and was reported in 1999. The hormone name is based on its role as a "growth hormone-releasing peptide", with reference to the Proto-Indo-European root "gʰre-", meaning "to grow". The "GHRL" gene produces mRNA which has four exons. Five products arise: the first is the 117-amino acid "preproghrelin". (It is homologous