title: GH-releasing activity of Hexarelin, a new growth hormone releasing peptide, in infant and adult rats.
abstract: In recent years several synthetic peptides have been shown to be active in inducing GH secretion in different mammalian species. Among them GHRP-6, GHRP-1 and GHRP-2 have demonstrated high effectiveness and high selectivity in stimulating GH release. In the present paper we report studies on the GH-secreting properties of a GHRP analog in which Trp was substituted with the chemically more stable 2-Methyl-Trp. In studies performed in conscious 10-day old rats, the hexapeptide Hexarelin (His-D-2Me-Trp-Ala-Trp-D-Phe-Lys-NH2) resulted very active in stimulating GH secretion. In anesthetized adult male rats, i.v. administration of GHRP-6 or Hexarelin elicited prompt GH release with peak GH levels occurring within 10 min At all the doses tested, the 2 peptides possessed similar effectiveness in stimulating GH release. Hexarelin given s.c. elicited a long-lasting GH release and was slightly more effective than GHRP-6. In conclusion, these findings indicate that Hexarelin is a highly effective GH releaser and might represent a valuable diagnostic and/or therapeutic tool in clinical practice.
authors.affiliation: Department of Pharmacology, School of Medicine, University of Milan, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Deghenghi
authors.forename: M M
authors.initials: MM
authors.lastname: Cananzi
authors.forename: A
authors.initials: A
authors.lastname: Torsello
authors.forename: C
authors.initials: C
authors.lastname: Battisti
authors.forename: E E
authors.initials: EE
authors.lastname: Muller
authors.forename: V
authors.initials: V
authors.lastname: Locatelli
mesh_terms: D000375:Aging / Q000502:physiology; D000595:Amino Acid Sequence; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D013007:Growth Hormone-Releasing Hormone / Q000031:analogs & derivatives* / Q000494:pharmacology*; D006133:Growth Substances / Q000494:pharmacology*; D008297:Male; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000494:pharmacology*; D051381:Rats; D013004:Somatostatin / Q000097:blood / Q000378:metabolism*; D013329:Structure-Activity Relationship
chemical_list: D006133:Growth Substances; D009842:Oligopeptides; C086184:hexarelin; D013004:Somatostatin; D013007:Growth Hormone-Releasing Hormone