title: In vivo action of a new octadecaneuropeptide (ODN) antagonist on gonadotropin-releasing hormone gene expression in the male rat brain.
abstract: It has been reported that several of the effects induced by octadecaneuropeptide (ODN) could be mediated by an activation of a metabotropic receptor. In order to investigate the role and mechanism of action of ODN in gonadotropin-releasing hormone (GnRH) neuron regulation, we studied the effects of the acute i.c.v. administration of ODN and of a new ODN antagonist to metabotropic receptor, cyclo(1-8)[Dleu(5)]OP, on GnRH mRNA expression as evaluated by in situ hybridization in castrated male rats. The administration of ODN produced a decrease in the hybridization signal while the administration of cyclo(1-8)[Dleu(5)]OP alone produced an 18% increase. When administrated concomitantly with ODN, the antagonist both inhibited the depressing effect of ODN and induced a 22% increase over the values detected in ODN-treated rats. The data suggest that the effect of ODN on GnRH mRNA expression might be mediated by interaction with metabotropic receptors.
authors.affiliation: European Institute for Peptide Research (IFRMP 23), Laboratory of Cellular and Molecular Neuroendocrinology, INSERM U413, UA CNRS, University of Rouen, Mont-Saint-Aignan, France.
authors.forename: V
authors.initials: V
authors.lastname: Compère
authors.forename: S
authors.initials: S
authors.lastname: Li
authors.forename: J
authors.initials: J
authors.lastname: Leprince
authors.forename: M C
authors.initials: MC
authors.lastname: Tonon
authors.forename: H
authors.initials: H
authors.lastname: Vaudry
authors.forename: G
authors.initials: G
authors.lastname: Pelletier
mesh_terms: D000818:Animals; D002369:Castration / Q000379:methods; D026261:Diazepam Binding Inhibitor; D004347:Drug Interactions; D015870:Gene Expression / Q000187:drug effects*; D007987:Gonadotropin-Releasing Hormone / Q000235:genetics / Q000378:metabolism*; D017403:In Situ Hybridization / Q000379:methods; D008297:Male; D009479:Neuropeptides / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D010446:Peptide Fragments; D010456:Peptides, Cyclic / Q000737:chemistry / Q000494:pharmacology*; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D026261:Diazepam Binding Inhibitor; D009479:Neuropeptides; D010446:Peptide Fragments; D010456:Peptides, Cyclic; D012333:RNA, Messenger; C487836:cyclo(Arg-Pro-Gly-Leu-Leu-Asp-Leu-Lys); C067529:diazepam binding inhibitor (33-50); D007987:Gonadotropin-Releasing Hormone