Growth Hormone-Releasing Peptides and Their Analogs

@article{Camanni1998GrowthHP,
  title={Growth Hormone-Releasing Peptides and Their Analogs},
  author={Franco Camanni and Ezio Ghigo and Emanuela Arvat},
  journal={Frontiers in Neuroendocrinology},
  year={1998},
  volume={19},
  pages={47-72}
}
Growth hormone-releasing peptides (GHRPs) are a series of hepta (GHRP-1)- and hexapeptides (GHRP-2, GHRP-6, Hexarelin) that have been shown to be effective releasers of GH in animals and humans. More recently, a series of nonpeptidyl GH secretagogues (L-692,429, L-692,585, MK-0677) were discovered using GHRP-6 as a template. Some cyclic peptides as well as penta-, tetra-, and pseudotripeptides have also been described. This review summarizes recent developments in our understanding of the GHRPs… 
Antiproliferative and GH-inhibitory activity of chimeric peptides consisting of GHRP-6 and somatostatin.
TLDR
One of the chimeric peptides, GSD, exhibited significantly greater anti-neoplastic and GH-inhibitory activity, as compared to RC-160, and may be of potential importance in the therapy of acromegaly, as well as provide novel tools to study the regulation of GH secretion by GHRP and somatostatin.
Identification of a novel growth hormone releasing peptide (a glycine analogue of GHRP-2) in a seized injection vial.
TLDR
A qualitative analysis by liquid chromatography coupled to high-resolution tandem mass spectrometry with a quadrupole time-of-flight analyzer was performed to identify a new heptapeptide - a glycine analogue of GHRP-2, which may indicate a new approach to circumvent a detection of doping practices.
Known and Unknown Growth Hormone Secretagogue Receptors and their Ligands
TLDR
Ghrelin is providing new understanding about how the gastrointestinal tract and nutritional intake regulate appetite, food intake and energy expenditure as well as the function of hypothalamus-pituitary axis, particularly the somatotroph function.
Physiology of ghrelin and related peptides.
Ghrelin in the Regulation of GH Secretion and Other Pituitary Hormones
TLDR
Ghrelin plays a relevant role in the modulation of the hypothalamus-pituitary-gonadal axis function, with a predominantly central nervous system (CNS)-mediated inhibitory effect upon the gonadotropin pulsatility both in animals and in humans.
Selective lack of growth hormone (GH) response to the GH-releasing peptide hexarelin in patients with GH-releasing hormone receptor deficiency.
TLDR
It is concluded that an intact G HRH signaling system is critical for GHRPs to exert their effect on GH release, but that the GHRH system is not necessary for the effect of GHRP on PRL and ACTH secretion.
Heterogeneity of Ghrelin/Growth Hormone Secretagogue Receptors
TLDR
This review highlights the most recently discovered features of GHS-R1a and the emerging evidence for a novel group of receptors that are not of the GHS1a type; these appear involved in the transduction of the multiple levels of information provided by GHS and ghrelin.
Pharmacological profile of a new orally active growth hormone secretagogue, SM-130686.
TLDR
An orally active GHS, SM-130686, which acts through the GHS receptor, is described here, which is likely that SM- 130686 is a partial agonist for the G HS receptor.
Regulation of Growth Hormones
TLDR
The results suggest that the actions of ghrelin and synthetic GHS closely parallel each other, in a manner that is consistent with an increase of hormone.
Natural (ghrelin) and synthetic (hexarelin) GH secretagogues stimulate H9c2 cardiomyocyte cell proliferation.
TLDR
A dose-dependent and specific stimulation of cardiomyocyte thymidine incorporation by natural and synthetic GHS analogues is demonstrated, suggesting increased cell proliferation and binding of GHS to H9c2Cardiomyocytes cell membranes and support potential peripheral effects of G HS on the cardiovascular system independent of an increased GH secretion.
...
...

References

SHOWING 1-10 OF 154 REFERENCES
In vitro characterization of four novel classes of growth hormone-releasing peptide.
TLDR
It is concluded that these novel compounds are potent and direct stimulators of pituitary GH release, with in vitro attributes that suggest mediation via a specific GHRP-like mechanism.
On the actions of the growth hormone-releasing hexapeptide, GHRP.
TLDR
Evidence indicates that these opiates and GHRP administered together synergistically release GH, demonstrating the independent action(s) ofGHRP and the opiates, and the complementary, rather dramatic synergistic interaction of G HRP, GHRH, and dermorphin or GHRp, G HRh, and 2549 in releasing GH again strongly supports the independent actions of these compounds.
Identification of a new G-protein-linked receptor for growth hormone secretagogues.
TLDR
A specific high affinity binding site in porcine and rat anterior pituitary membranes that mediates the activity of these secretagogues has now been identified and is tightly correlated with GH-secretory activity.
Growth hormone (GH) responses to the hexapeptide GH-releasing peptide and GH-releasing hormone (GHRH) in the cynomolgus macaque: evidence for non-GHRH-mediated responses.
TLDR
GHRP causes a potent dose-dependent release of GH in this primate species since GHRP can produce a greater maximal GH response than GHRH, mechanisms other than release of endogenous G HRH must be involved.
Central effects of growth hormone-releasing hexapeptide (GHRP-6) on growth hormone release are inhibited by central somatostatin action.
TLDR
It is concluded that the hypothalamus is a major target for GHRP-6 in vivo, and it is suggested that somatostatin may block this activation via receptors known to be located on or near the GRF cells themselves.
Role of selected endogenous peptides in growth hormone-releasing hexapeptide activity: analysis of growth hormone-releasing hormone, thyroid hormone-releasing hormone, and gonadotropin-releasing hormone.
TLDR
The results of this study suggest that synergy between GHRH and GHRp-6 seen in pharmacological studies is physiologically relevant, and that TRH and GnRH are not endogenous analogs of GHRP-6.
GH Releasing Peptides - Structure and Kinetics
  • C. Bowers
  • Biology, Medicine
    The Journal of pediatric endocrinology
  • 1993
TLDR
The results demonstrate GHRPs' potential importance at the theoretical as well as pharmaceutical level and the synergistic release of GH induced by the combined i.v. and oral administration in children with various degrees of GH deficiency.
Different growth hormone (GH) response to GH-releasing peptide and GH-releasing hormone in hyperthyroidism.
TLDR
It is shown that hyperthyroid patients have a normal GH response to GHRP-6 together with a blunted GH responsiveness to G HRH, suggesting that thyroid hormones modulate GH release induced by these two peptides in a differential way.
...
...