DRPSHP

Scientific Reference

GHRP-2

Evidence profile: Controlled human evidence

GHRP-2, with the non-proprietary name pralmorelin, is a six-residue synthetic peptide that switches on the ghrelin receptor GHS-R1a. Half of its residues are D-amino acids, among them the non-natural D-2-naphthylalanine, a design habit it shares with other synthetic growth hormone-releasing peptides. Those compounds were found by screening for growth hormone release at a time when their receptor was unknown, and ghrelin, the receptor's own ligand, turned up later. It has been used in receptor and pituitary cell assays, animal experiments and short human endocrine studies measuring hormone output. Longer human data are limited, and the effect is not confined to growth hormone, because other pituitary and adrenal hormones also rise.

Mechanism of Action

GHRP-2 is reported to be an agonist at GHS-R1a, a G protein-coupled receptor found on anterior pituitary somatotrophs and on hypothalamic neurons. In somatotrophs the receptor couples mainly to Gq and phospholipase C, and the calcium rise that follows drives growth hormone secretion. That is a different route from growth hormone-releasing hormone, which signals through its own receptor and cyclic AMP. Some of the response is thought to be hypothalamic, via GHRH neurons and somatostatin signalling. Human studies have recorded modest increases in ACTH, cortisol and prolactin alongside growth hormone.

Molecular Information

  • Type: Growth hormone secretagogue (GHRP)
  • Molecular weight: 818.0 g/mol
  • Molecular formula: C45H55N9O6
  • CAS: 158861-67-7

Published Research

  • The combined administration of GH-releasing peptide-2 (GHRP-2), TRH and GnRH to men with prolonged critical illness evokes superior endocrine and metabolic effects compared to treatment with GHRP-2 alone

    Van den Berghe G et al. · Clinical endocrinology · 2002 · Clinical

    PMID 12030918 — View on PubMed

  • Synergy of L-arginine and GHRP-2 stimulation of growth hormone in men and women: modulation by exercise

    Wideman L et al. · American journal of physiology. Regulatory, integrative and comparative physiology · 2000 · Clinical

    PMID 11004017 — View on PubMed

  • Growth hormone-releasing peptide-2 infusion synchronizes growth hormone, thyrotrophin and prolactin release in prolonged critical illness

    Van den Berghe G et al. · European journal of endocrinology · 1999 · Clinical

    PMID 10037246 — View on PubMed

  • Treatment effects of intranasal growth hormone releasing peptide-2 in children with short stature

    Pihoker C et al. · The Journal of endocrinology · 1997 · Clinical

    PMID 9390009 — View on PubMed