title: The effects of neuropeptide S on general anesthesia in rats.
abstract: BACKGROUND
  Neuropeptide S (NPS) and its receptor (NPSR) is a novel neuropeptide system that regulates arousal and anxiety. A link between natural sleep and general anesthesia has been suggested. Therefore, we hypothesized that the NPS neuronal system may also modulate general anesthesia.
  
  
  METHODS
  The effects of intracerebroventricular NPS and [D-Cys(tBu)(5)]NPS, a peptide NPSR antagonist, on ketamine and thiopental anesthesia time were measured in rats. Anesthesia time was defined as the interval between the loss of righting reflex and its recovery.
  
  
  RESULTS
  Intracerebroventricular NPS 1 to 30 nmol significantly reduced ketamine anesthesia time, showing a bell-shaped dose-response curve. [D-Cys(tBu)(5)]NPS 20 nmol antagonized NPS 1 nmol effects and was per se able to increase ketamine anesthesia time. Similar results were obtained investigating thiopental anesthesia time that was significantly reduced by NPS and prolonged by [D-Cys(tBu)(5)]NPS.
  
  
  CONCLUSIONS
  NPS via selective NPSR activation stimulates the wakefulness-promoting pathway, thus reducing anesthesia duration. The endogenous NPS/NPSR system seems to tonically control these pathways.
authors.affiliation: Department of Anesthesiology, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Kushikata
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Yoshida
authors.forename: Mihoko
authors.initials: M
authors.lastname: Kudo
authors.forename: Severo
authors.initials: S
authors.lastname: Salvadori
authors.forename: Girolamo
authors.initials: G
authors.lastname: Calo
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Hirota
mesh_terms: D000768:Anesthesia, General / Q000379:methods; D000818:Animals; D004305:Dose-Response Relationship, Drug; D057967:Infusions, Intraventricular; D009479:Neuropeptides / Q000008:administration & dosage*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D014851:Wakefulness / Q000187:drug effects* / Q000502:physiology
chemical_list: D009479:Neuropeptides; C534458:neuropeptide S, rat