GHRP-2

Mechanism (as reported)

Cell and culture studies reported that GHRP-2 does not act via the human growth hormone-releasing factor (GRF) receptor in GC cells (PMID: 9798733). In cultured human acromegalic tumor cells, research concluded that GHRP-2 stimulated GH secretion mainly via a PKC pathway (with reported differences versus GHRH-related signaling) and did not act on the same receptor as GHRH on those tumor-derived somatotrophs. (PMID: 9688350)

Key findings (each cites a source)

• Pralmorelin is described as GHRP-2 and a series of synthetic growth hormone-releasing peptides were developed; the work describes pralmorelin/GHRP-2 as orally active and synthetic, with activity related to mimicking ghrelin. (PMIDs: 15230633) [PMID 15230633]
• Research reported that pralmorelin/GHRP-2 increased plasma GH levels in healthy subjects, while the effect was significantly lower in patients with GH deficiency; a receiver-operating characteristic analysis provided a GH peak cut-off threshold value of 15.0 microg/L for identifying GH deficiency. (PMIDs: 15230633) [PMID 15230633]
• A human study reported that acute GHRP-2 increased food intake in lean healthy men during an ad libitum buffet meal after subcutaneous infusion, and that serum GH levels rose during infusion. (PMIDs: 15699539) [PMID 15699539]
• In rat pituitary GC cells, research reported that GHRP-2 did not alter intracellular cAMP, [Ca2+]i, or GH secretion in cells lacking the human GRF receptor, and concluded that GHRP-2 does not act through the GRF receptor. (PMIDs: 9798733) [PMID 9798733]
• In cultured human acromegalic tumor cells, research reported that application of GHRP-2 increased GH secretion from all tested tumor cultures and that the study concluded GHRP-2 increases GH secretion mainly via the PKC pathway (with reported differences from the effects of GHRH). (PMIDs: 9688350) [PMID 9688350]
• In an arthritic rat model, research reported that GHRP-2 administration ameliorated external arthritis symptoms and decreased serum IL-6 levels; in vitro, peritoneal macrophage cultures exposed to GHRP-2 prevented endotoxin-induced IL-6 and decreased nitrite/nitrate release. (PMIDs: 9688350) [PMID 9688350]
• An analytical study in an anti-doping context reported identification of a novel heptapeptide described as a glycine analogue of GHRP-2 in a seized injection vial, using liquid chromatography coupled to high-resolution tandem mass spectrometry and de novo sequencing. (PMIDs: 30051972) [PMID 30051972]