Ghrelin, an endogenous ligand for the growth-hormone-secretagogue receptor, was isolated
from human and rat stomach. It is a 28-amino acid peptide with a posttranslational acyl
modification that is indispensable for its activity. In addition to stimulating growth-hormone
secretion, food intake, and body weight gain, ghrelin also plays a role in a variety of other
systems, including circulation, digestion, and cell proliferation. This review will focus on the
discovery, structural characteristics, tissue distribution, and physiological functions of …