title: Differential effects of deltorphin on arginine and galanin-induced growth hormone secretion in healthy man.
abstract: Recently we demonstrated the inhibitory action on Growth Hormone (GH) secretion of an opioid heptapeptide, deltorphin (DT), that is highly selective in binding delta-opioid receptors. To investigate the possible mechanism leading to the decrease in GH secretion by specific activation of delta-opioidergic pathway in man, we compared, in normal subjects, the effect of DT on GH secretion responses to two different GH secretagogues, namely arginine (ARG) and galanin (GAL). DT completely blunted the GH response to ARG, whereas it attenuated the GH response to GAL, but not at a statistically significant level. We suggest that the specific activation of delta-opioid receptors in man may exert an inhibitory influence on GH secretion principally by modulating endogenous hypothalamic somatostatin (SRIH) release.
authors.affiliation: Cattedra di Endocrinologia, Università di Ferrara, Italy.
authors.forename: E C
authors.initials: EC
authors.lastname: degli Uberti
authors.forename: S
authors.initials: S
authors.lastname: Salvadori
authors.forename: G
authors.initials: G
authors.lastname: Trasforini
authors.forename: M R
authors.initials: MR
authors.lastname: Ambrosio
authors.forename: A
authors.initials: A
authors.lastname: Margutti
authors.forename: M
authors.initials: M
authors.lastname: Bondanelli
authors.forename: R
authors.initials: R
authors.lastname: Rossi
authors.forename: A
authors.initials: A
authors.lastname: Valentini
mesh_terms: D000328:Adult; D001120:Arginine / Q000494:pharmacology*; D001667:Binding, Competitive; D019004:Galanin / Q000494:pharmacology*; D013006:Growth Hormone / Q000378:metabolism*; D006801:Humans; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism; D007260:Infusion Pumps; D007262:Infusions, Intravenous; D008297:Male; D009842:Oligopeptides / Q000378:metabolism / Q000494:pharmacology*; D017465:Receptors, Opioid, delta / Q000819:agonists / Q000187:drug effects* / Q000378:metabolism; D016037:Single-Blind Method; D013004:Somatostatin / Q000378:metabolism
chemical_list: D009842:Oligopeptides; D017465:Receptors, Opioid, delta; C059567:deltorphin; D013004:Somatostatin; D019004:Galanin; D013006:Growth Hormone; D001120:Arginine