GHRP (Growth Hormone Releasing Peptide)
Definition
A family of synthetic peptides that release growth hormone by activating the ghrelin receptor. GHRP-2, GHRP-6, hexarelin and ipamorelin belong to it, and they differ in how much hunger, cortisol and prolactin signalling they bring with them.
Terms used in this definition
Other entries this definition refers to.
Where this term comes up
Entries whose definition mentions GHRP (Growth Hormone Releasing Peptide).
What this means for research sourcing
Mechanistic terms like this describe how research compounds behave in vitro. See the mechanism overviews for compounds Volta stocks.
Related Terms in Pharmacology
GHRH (Growth Hormone Releasing Hormone)
The hypothalamic hormone that instructs the pituitary to synthesise and release growth hormone. Sermorelin, tesamorelin and CJC-1295 are analogues of it, and they act at a different receptor from the GHRPs, which is the basis for studying the two together.
GHS-R1a (Growth Hormone Secretagogue Receptor)
The ghrelin receptor, a G protein-coupled receptor expressed mainly in the pituitary and hypothalamus. Activation by ghrelin or by a GHRP produces a growth hormone pulse along with appetite and reward signalling.
Somatostatin
The hypothalamic hormone that brakes growth hormone release, acting as the counterweight to GHRH. The alternation between the two is what makes natural growth hormone secretion pulsatile rather than continuous.
Pulsatile Release
Secretion in bursts rather than at a steady level. Growth hormone and GnRH are both pulsatile, and the pattern carries information: continuous stimulation of a GnRH receptor suppresses the axis it would otherwise drive.
IGF-1 (Insulin-Like Growth Factor 1)
A liver-produced hormone that mediates much of what growth hormone does to growth, metabolism and body composition. Serum IGF-1 is the usual laboratory proxy for growth hormone exposure because it is stable where GH itself is pulsatile.
Pituitary Gland
The gland at the base of the brain that releases growth hormone, the gonadotropins and other hormones on hypothalamic instruction. Secretagogues and releasing-hormone analogues both act here rather than at the tissue where the effect appears.
Hypothalamus
The brain region joining the nervous and endocrine systems, releasing GHRH, GnRH and somatostatin to control the pituitary. It also carries much of the appetite circuitry that incretin agonists act on.
GnRH (Gonadotropin-Releasing Hormone)
The hypothalamic hormone released in pulses that tells the pituitary to secrete luteinising hormone and follicle-stimulating hormone. Continuous rather than pulsatile stimulation of its receptor has the opposite effect and shuts those hormones down.
