Ghrelin receptor
Category: Receptors · Last updated
The growth hormone secretagogue receptor 1a (GHS-R1a), commonly called the ghrelin receptor, is a Gαq-coupled G-protein-coupled receptor expressed on pituitary somatotroph cells, hypothalamic neurons, and several peripheral tissues. The endogenous ligand is ghrelin, a 28-residue acylated peptide produced predominantly in the stomach.
Signaling
Ghrelin binding activates phospholipase C → IP3 → calcium release. In pituitary somatotrophs, the calcium pulse triggers vesicular release of stored Growth_hormone. In hypothalamic NPY/AgRP neurons, the same pathway drives appetite signaling.
Relevance to research peptides
- Ipamorelin · selective ghrelin-receptor agonist (Aib-His-D-2Nal-D-Phe-Lys-NH₂)
- GHRP-6 · older, less selective ghrelin-receptor agonist
- Hexarelin · older, less selective ghrelin-receptor agonist