Growth hormone-releasing peptides and their analogs.
Level 5 - mechanism / opinion, no new human data
Narrative review without systematic search methodology
PubMed 9465289 · doi:10.1006/frne.1997.0158
What was done
This narrative review summarizes the pharmacology, receptor biology, mechanisms of action, and clinical/physiological responses to growth hormone-releasing peptides (GHRP-1, GHRP-2, GHRP-6, Hexarelin) and nonpeptidyl secretagogues (L-692,429, L-692,585, MK-0677) in animals and humans.
What was found
The abstract reports qualitative physiological findings without numerical data. GHRPs and their analogs stimulate GH release in a reproducible, dose-dependent manner across IV, SC, intranasal, and oral routes. GH response magnitude is identical between sexes, increases from birth to puberty, and decreases in aging. GHRPs act synergistically with GHRH via a distinct cloned G-protein-coupled receptor and are only blunted, rather than abolished, by classic GHRH inhibitors such as glucose, free fatty acids, glucocorticoids, and exogenous somatostatin. Responsiveness is maintained in acromegaly, anorexia nervosa, hyperthyroidism, obesity, and idiopathic short stature, but is nearly absent in Cushing's syndrome and pituitary stalk disconnection.
Why it matters
This review synthesizes the mechanistic and early clinical foundations of synthetic growth hormone secretagogues shortly after the discovery and cloning of the GHRP receptor, prior to the identification of ghrelin as its endogenous ligand.
Limits
The abstract provides no quantitative data or statistical measures. As an unsystematic narrative review, it lacks defined search parameters, study selection criteria, and formal quality assessment of the cited literature. Long-term therapeutic outcomes and safety profiles are not evaluated.
Cited by
- supports GHRP-2 and GHRP-6 are growth hormone-releasing peptides that stimulate the body's natural release of growth hormone.