Ghrelin and des-acyl ghrelin: two major forms of rat ghrelin peptide in gastrointestinal tissue

Biochem Biophys Res Commun. 2000 Dec 29;279(3):909-13. doi: 10.1006/bbrc.2000.4039.

Abstract

Ghrelin, a novel peptide purified from stomach, is the endogenous ligand for the growth hormone secretagogue receptor and has potent growth hormone-releasing activity. The Ser3 residue of ghrelin is modified by n-octanoic acid, a modification necessary for hormonal activity. We established two ghrelin-specific radioimmunoassays; one recognizes the octanoyl-modified portion and another the C-terminal portion of ghrelin. Using these radioimmunoassay systems, we found that two major molecular forms exist-ghrelin and des-n-octanoyl ghrelin. While ghrelin activates growth-hormone secretagogue (GHS) receptor-expressing cells, the nonmodified des-n-octanyl form of ghrelin, designated as des-acyl ghrelin, does not. In addition to these findings, our radioimmunoassay systems also revealed high concentrations of ghrelin in the stomach and small intestine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Duodenum / metabolism*
  • Gastric Mucosa / metabolism*
  • Ghrelin
  • Immunoglobulins / immunology
  • Male
  • Molecular Sequence Data
  • Peptide Hormones*
  • Peptides / analysis*
  • Peptides / immunology
  • Radioimmunoassay
  • Rats
  • Rats, Sprague-Dawley
  • Tissue Distribution

Substances

  • Ghrelin
  • Immunoglobulins
  • Peptide Hormones
  • Peptides
  • ghrelin, des-n-octanoyl