title: [tBu-D-Gly5]NPS, a pure and potent antagonist of the neuropeptide S receptor: in vitro and in vivo studies.
abstract: Neuropeptide S (NPS) regulates various biological functions by selectively activating the NPS receptor (NPSR). Recently, the NPSR ligand [(t)Bu-D-Gly(5)]NPS was generated and in vitro characterized as a pure antagonist at the mouse NPSR. In the present study the pharmacological profile of [(t)Bu-D-Gly(5)]NPS has been investigated. [(t)Bu-D-Gly(5)]NPS activity was evaluated in vitro in the calcium mobilization assay at the rat NPSR and in vivo in the locomotor activity and righting reflex tests in mice and in the elevated plus maze and defensive burying assays in rats. In vitro, [(t)Bu-D-Gly(5)]NPS was inactive per se while it inhibited the calcium mobilization induced by 30 nM NPS (pK(B) 7.42). In Schild analysis experiments [(t)Bu-D-Gly(5)]NPS (0.1-10 μM) produced a concentration-dependent rightward shift of the concentration-response curve to NPS, showing a pA(2) value of 7.17. In mouse locomotor activity experiments, supraspinal injection of [(t)Bu-D-Gly(5)]NPS (1-10 nmol) dose dependently counteracted NPS (0.1 nmol) stimulant effects. In the mouse righting reflex assay [(t)Bu-D-Gly(5)]NPS (0.1-10 nmol) fully prevented the arousal-promoting action of the natural peptide (0.1 nmol). Finally, [(t)Bu-D-Gly(5)]NPS (3-30 nmol) was able to completely block NPS (1 nmol) anxiolytic-like actions in rat elevated plus maze and defensive burying assays. Collectively, the present results demonstrated that [(t)Bu-D-Gly(5)]NPS behaves both in vitro and in vivo as a pure and potent NPSR antagonist. This compound represents a novel and useful tool for investigating the pharmacology and neurobiology of the NPS/NPSR system.
authors.affiliation: Department of Experimental and Clinical Medicine, Section of Pharmacology and Neuroscience Center and National Institute of Neuroscience, University of Ferrara, via Fossato di Mortara 19, 44121 Ferrara, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Ruzza
authors.forename: A
authors.initials: A
authors.lastname: Rizzi
authors.forename: V
authors.initials: V
authors.lastname: Camarda
authors.forename: A
authors.initials: A
authors.lastname: Pulga
authors.forename: G
authors.initials: G
authors.lastname: Marzola
authors.forename: M
authors.initials: M
authors.lastname: Filaferro
authors.forename: C
authors.initials: C
authors.lastname: Novi
authors.forename: V
authors.initials: V
authors.lastname: Ruggieri
authors.forename: E
authors.initials: E
authors.lastname: Marzola
authors.forename: G
authors.initials: G
authors.lastname: Vitale
authors.forename: S
authors.initials: S
authors.lastname: Salvadori
authors.forename: R
authors.initials: R
authors.lastname: Guerrini
authors.forename: G
authors.initials: G
authors.lastname: Calo'
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D057809:HEK293 Cells; D006801:Humans; D057967:Infusions, Intraventricular; D007278:Injections, Spinal; D007700:Kinetics; D008297:Male; D018782:Maze Learning / Q000187:drug effects / Q000502:physiology; D051379:Mice; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D009479:Neuropeptides / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D043562:Receptors, G-Protein-Coupled / Q000037:antagonists & inhibitors* / Q000378:metabolism; D018013:Receptors, Neuropeptide / Q000037:antagonists & inhibitors* / Q000378:metabolism; D057897:Reflex, Righting / Q000187:drug effects / Q000502:physiology; D014162:Transfection
chemical_list: C515062:NPSR1 protein, mouse; D009479:Neuropeptides; D043562:Receptors, G-Protein-Coupled; D018013:Receptors, Neuropeptide; C568280:neuropeptide S receptor, rat; C559118:neuropeptide S, tert-butylGly(5)-; D002118:Calcium