GHRP-2

GHRP-2, also called pralmorelin or KP-102, is a synthetic hexapeptide with the sequence D-Ala-D-2-Nal-Ala-Trp-D-Phe-Lys-NH2, a molecular weight near 818 g/mol and CAS 158861-67-7. It belongs to a series of small synthetic peptides, three to five residues long, that mimic the actions of ghrelin, the octanoylated 28-residue stomach peptide identified as the endogenous ligand of the growth hormone secretagogue receptor. That receptor, GHS-R1a, is a G protein-coupled receptor cloned from pituitary and hypothalamic tissue of swine.

GHRP-2 in the research literature

Rodent and canine pharmacology has been reported in some detail. In conscious rats the growth hormone-releasing activity of KP-102 exceeded that of exogenous GHRH, while under pentobarbital anaesthesia, a state in which endogenous somatostatin secretion is reduced, the two were approximately equivalent. Activity was absent in hypophysectomised rats and reduced in median eminence-lesioned rats, which the authors read as evidence that endogenous GHRH is required for its full effect. KP-102 also stimulated growth hormone secretion directly from cultured rat anterior pituitary cells, though less potently than GHRH in that assay, and in conscious rats it raised ACTH and corticosterone but not prolactin.