The effects of neuropeptide S on general anesthesia in rats.

Authors :: Kushikata T
Yoshida H
Kudo M
Salvadori S
Calo G
Hirota K
Source :: Anesthesia and analgesia [Anesth Analg] 2011 Apr; Vol. 112 (4), pp. 845-9. Date of Electronic Publication: 2011 Feb 02.
Publication Year :: 2011
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.<br />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.<br />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.<br />Conclusion: 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.