title: Ghrelin: structure and function.
abstract: Small synthetic molecules called growth hormone secretagogues (GHSs) stimulate the release of growth hormone (GH) from the pituitary. They act through the GHS-R, a G protein-coupled receptor whose ligand has only been discovered recently. Using a reverse pharmacology paradigm with a stable cell line expressing GHS-R, we purified an endogenous ligand for GHS-R from rat stomach and named it "ghrelin," after a word root ("ghre") in Proto-Indo-European languages meaning "grow." Ghrelin is a peptide hormone in which the third amino acid, usually a serine but in some species a threonine, is modified by a fatty acid; this modification is essential for ghrelin's activity. The discovery of ghrelin indicates that the release of GH from the pituitary might be regulated not only by hypothalamic GH-releasing hormone, but also by ghrelin derived from the stomach. In addition, ghrelin stimulates appetite by acting on the hypothalamic arcuate nucleus, a region known to control food intake. Ghrelin is orexigenic; it is secreted from the stomach and circulates in the bloodstream under fasting conditions, indicating that it transmits a hunger signal from the periphery to the central nervous system. Taking into account all these activities, ghrelin plays important roles for maintaining GH release and energy homeostasis in vertebrates.
authors.affiliation: Molecular Genetics, Institute of Life Science, Kurume University, Hyakunenkouen 1-1, Kurume, Fukuoka 839-0864, Japan. mkojima@lsi.kurume-u.ac.jp
authors.forename: Masayasu
authors.initials: M
authors.lastname: Kojima
authors.forename: Kenji
authors.initials: K
authors.lastname: Kangawa
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D054439:Ghrelin; D006801:Humans; D008969:Molecular Sequence Data; D036361:Peptide Hormones / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D013329:Structure-Activity Relationship; D014018:Tissue Distribution
chemical_list: D054439:Ghrelin; D036361:Peptide Hormones