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
Growth hormone secretagogue receptor coupled receptors (GPCRs). Various studies suggest that GHS-R1a specifically forms dimers with the following hormone and neurotransmitter receptors: somatostatin receptor 5, dopamine receptor type 2 (DRD2), melanocortin-3 receptor (MC3R), and serotonin receptor type 2C (5-HT receptor). See "Function" section below for details on the purported functions of these heterodimers. The binding of ghrelin to GHS-R1a in pituitary cells stimulates the secretion of growth hormone (GH) by the pituitary gland. One important feature of GHS-R1a is that there is still some activity in the receptor even when it is not actively being stimulated. This is called constitutive activity, and it means