GHRP-6

Growth hormone-releasing peptide 6 (GHRP-6) (developmental code name SKF-110679), also known as growth hormone-releasing hexapeptide, is one of several synthetic met-enkephalin analogues that include unnatural D-amino acids, were developed for their growth hormone-releasing activity and are called growth hormone secretagogues. They lack opioid activity but are potent stimulators of growth hormone (GH) release. These secretagogues are distinct from growth hormone releasing hormone (GHRH) in that they share no sequence relation and derive their function through activation of a completely different receptor. This receptor was originally called the growth hormone secretagogue receptor (GHSR), but due to subsequent discoveries, the hormone ghrelin is now considered the receptor's natural endogenous ligand, and it has been renamed as the ghrelin receptor. Therefore, these GHSR agonists act as synthetic ghrelin mimetics.

GHRP-6

Clinical data
ATC code	None
Pharmacokinetic data
Bioavailability	Oral: <1.0%
Elimination half-life	2.5 hours
Identifiers
IUPAC name L-histidyl-D-tryptophyl-L-alanyl-L-tryptophyl-D-phenylalanyl-L-Lysinamide
CAS Number	87616-84-0 Y
PubChem CID	5486806
ChemSpider	26333269 N
UNII	4H7N4I6X6A
CompTox Dashboard (EPA)	DTXSID30904007
Chemical and physical data
Formula	C46H56N12O6
Molar mass	873.032 g·mol−1
3D model (JSmol)	Interactive image
SMILES C[C@@H](C(=O)N[C@@H](Cc1c[nH]c2c1cccc2)C(=O)N[C@H](Cc3ccccc3)C(=O)N[C@@H](CCCCN)C(=O)N)NC(=O)[C@@H](Cc4c[nH]c5c4cccc5)NC(=O)[C@H](Cc6c[nH]cn6)N
InChI InChI=InChI=1S/C46H56N12O6/c1-27(54-44(62)39(20-29-23-51-35-15-7-5-13-32(29)35)57-43(61)34(48)22-31-25-50-26-53-31)42(60)56-40(21-30-24-52-36-16-8-6-14-33(30)36)46(64)58-38(19-28-11-3-2-4-12-28)45(63)55-37(41(49)59)17-9-10-18-47/h2-8,11-16,23-27,34,37-40,51-52H,9-10,17-22,47-48H2,1H3,(H2,49,59)(H,50,53)(H,54,62)(H,55,63)(H,56,60)(H,57,61)(H,58,64)/t27-,34-,37-,38+,39+,40-/m0/s1 N Key:WZHKXNSOCOQYQX-FUAFALNISA-N N
NY (what is this?)  (verify)

It has been discovered that when GHRP-6 and insulin are administered simultaneously, GH response to GHRP-6 is increased (1). However, the consumption of carbohydrates and/or dietary fats, around the administration window of GH secretagogues significantly blunts the GH release. A recent study in normal mice showed significant differences in body composition, muscle growth, glucose metabolism, memory and cardiac function in the mice being administered the GHRP-6 (2). There are still many questions regarding this fairly new compound.

See also

• List of growth hormone secretagogues

Further reading

• Korbonits M, Goldstone AP, Gueorguiev M, Grossman AB (April 2004). "Ghrelin--a hormone with multiple functions". Frontiers in Neuroendocrinology. 25 (1): 27–68. doi:10.1016/j.yfrne.2004.03.002. PMID 15183037. S2CID 24821233.
• Peñalva A, Carballo A, Pombo M, Casanueva FF, Dieguez C (January 1993). "Effect of growth hormone (GH)-releasing hormone (GHRH), atropine, pyridostigmine, or hypoglycemia on GHRP-6-induced GH secretion in man". The Journal of Clinical Endocrinology and Metabolism. 76 (1): 168–171. doi:10.1210/jcem.76.1.8421084. PMID 8421084.
• Camanni F, Ghigo E, Arvat E (January 1998). "Growth hormone-releasing peptides and their analogs". Frontiers in Neuroendocrinology. 19 (1): 47–72. doi:10.1006/frne.1997.0158. PMID 9465289. S2CID 31400577.
• Adeghate E, Ponery AS (July 2002). "Ghrelin stimulates insulin secretion from the pancreas of normal and diabetic rats". Journal of Neuroendocrinology. 14 (7): 555–560. doi:10.1046/j.1365-2826.2002.00811.x. PMID 12121492. S2CID 26490804.
• McGirr R, McFarland MS, McTavish J, Luyt LG, Dhanvantari S (December 2011). "Design and characterization of a fluorescent ghrelin analog for imaging the growth hormone secretagogue receptor 1a". Regulatory Peptides. 172 (1–3): 69–76. doi:10.1016/j.regpep.2011.08.011. PMID 21893106. S2CID 8213917.
• Koh B, Hardie M (2013). "We need an advocate against ASADA's power in doping control". The Conversation.