Growth hormone-releasing peptide 6 (GHRP-6) (developmental code name SKF-110679), also known as growth hormone-releasing hexapeptide, is one of several
syntheticmet-enkephalinanalogues 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
endogenousligand, and it has been renamed as the ghrelin receptor. Therefore, these GHSR agonists act as synthetic ghrelin mimetics.
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.
^Cabrales A, Gil J, Fernández E, Valenzuela C, Hernández F, García I, et al. (January 2013). "Pharmacokinetic study of Growth Hormone-Releasing Peptide 6 (GHRP-6) in nine male healthy volunteers". European Journal of Pharmaceutical Sciences. 48 (1–2): 40–46.
doi:
10.1016/j.ejps.2012.10.006.
PMID23099431.
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.
PMID15183037.
S2CID24821233.
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.
PMID8421084.
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.
PMID9465289.
S2CID31400577.