Abstract

Nociceptin and its receptor are widely expressed in the central nervous system and are involved in the modulation of nociception. We have previously reported that the minimum anesthetic alveolar concentrations for volatile anesthetics do not differ between nociceptin receptor knockout (NOP-/-) mice and wild-type (NOP+/+) mice. In the present study, we investigated whether the nociceptin system is involved in the antinociceptive action of nitrous oxide. Using the acetic acid-induced writhing test, we showed that nitrous oxide had significantly less analgesic action in NOP-/- mice than in NOP+/+ mice. Furthermore, when anesthetized with a mixture of halothane and nitrous oxide (70%), intraperitoneal injection of acetic acid resulted in an increase of plasma adrenocorticotropic hormone concentrations in NOP-/- mice but not in NOP+/+ mice. An immunohistochemical study showed that nitrous oxide exposure induced c-Fos expression in the spinal cords of NOP+/+ mice but not in those of NOP-/- mice. These results together suggest that the antinociceptive action of nitrous oxide is, at least partly, mediated by the nociceptin system.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.