The ghrelin receptor (GHSR) is a GPCR expressed in hypothalamus, pituitary, and peripheral sites. It is central to discussions of orexigenic signaling and GH secretagogue research.
What it is
GHSR type 1a is the functional receptor for acylated ghrelin. Synthetic growth hormone secretagogues studied in research settings often act as GHSR agonists, which is why this receptor page anchors several peptide discussions.
How it works
Ligand-bound GHSR couples primarily through Gq/11 pathways, raising intracellular calcium and activating PKC-linked cascades in target neurons and pituitary cells.
Central GHSR activity influences appetite circuitry, while pituitary GHSR can contribute to GH release dynamics alongside GHRH input.
Biological role
Physiologically, ghrelin–GHSR signaling participates in meal initiation cues, energy homeostasis, and GH axis modulation. Research models explore receptor constitutive activity and biased agonism.
Proteins involved
- GHSR1a
- Ghrelin-O-acyltransferase (GOAT) for ligand activation
- Gq/11 proteins
- PLC / IP3–calcium machinery
Research summary
Structural and pharmacological studies define GHSR ligand preferences and signaling bias. Secretagogue peptides are frequently discussed in GHSR terms, but human outcomes remain indication- and compound-specific.
Descriptions summarize published mechanistic frameworks. Findings from cell culture or animal models should not be interpreted as proven clinical effects in humans.
Research limitations
Scientific references
- Kojima M, Kangawa K. Ghrelin discovery and receptor biology reviews.
- Howard AD et al. Early GHSR cloning literature and subsequent pharmacology reviews.