Gastrin-Releasing Peptide

Gastrin-releasing peptide (GRP) was originally isolated from the porcine stomach, and was believed to be the mammalian counterpart of the amphibian peptide bombesin – itself originally isolated from the porcine stomach and subsequently in other vertebrates. A large body of research indicates that GRP is distributed widely in the central nervous system of mammals in addition to the gastrointestinal tract. In mammals, bombesin-like peptides act through a family of at least three G protein-coupled receptors (GPCRs), namely the GRP-preferring receptor (GRPR), the NMB-preferring receptor, and bombesin receptor subtype-3, which is considered an orphan receptor. To date, it has been reported that GRP plays significant roles in many physiological processes, including food intake, circadian rhythms, male sexual behavior, and fear memory consolidation, through the specific GPCR, GRPR-mediated mechanisms.