title: Endogenous opioid and cannabinoid mechanisms are involved in the analgesic effects of celecoxib in the central nervous system.
abstract: OBJECTIVE
  In this study we analyzed the mechanisms underlying celecoxib-induced analgesia in a model of inflammatory pain in rats, using the intracerebroventricular (i.c.v.) administration of selective opioid and cannabinoid antagonists.
  
  
  RESULTS
  Analgesic effects of celecoxib were prevented by selective μ-(β-funaltrexamine) and δ-(naltrindole), but not κ-(nor-binaltorphimine) opioid antagonists, given i.c.v. 30 min before celecoxib. Similar pretreatment with AM 251, but not SR 144528, cannabinoid CB(1) and CB(2) receptor antagonists, respectively, prevented celecoxib-induced analgesia. The fatty acid amide hydrolase inhibitor, URB 597, also prevented celecoxib-induced analgesia.
  
  
  CONCLUSIONS
  Our data provided further evidence for the involvement of endogenous opioids and revealed a new cannabinoid component of the mechanism(s) underlying celecoxib-induced analgesia.
authors.affiliation: Laboratory of Inflammation and Pain, Department of Pharmacology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil.
authors.forename: R M
authors.initials: RM
authors.lastname: Rezende
authors.forename: P
authors.initials: P
authors.lastname: Paiva-Lima
authors.forename: W G P
authors.initials: WG
authors.lastname: Dos Reis
authors.forename: V M
authors.initials: VM
authors.lastname: Camêlo
authors.forename: A
authors.initials: A
authors.lastname: Faraco
authors.forename: Y S
authors.initials: YS
authors.lastname: Bakhle
authors.forename: J N
authors.initials: JN
authors.lastname: Francischi
mesh_terms: D000700:Analgesics / Q000494:pharmacology*; D000818:Animals; D002351:Carrageenan; D000068579:Celecoxib; D002490:Central Nervous System / Q000187:drug effects / Q000503:physiopathology; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology; D007249:Inflammation / Q000139:chemically induced / Q000188:drug therapy / Q000503:physiopathology; D008297:Male; D009271:Naltrexone / Q000031:analogs & derivatives / Q000494:pharmacology; D010146:Pain / Q000139:chemically induced / Q000188:drug therapy / Q000503:physiopathology; D010880:Piperidines / Q000494:pharmacology; D011720:Pyrazoles / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D043884:Receptor, Cannabinoid, CB1 / Q000037:antagonists & inhibitors / Q000502:physiology*; D017465:Receptors, Opioid, delta / Q000037:antagonists & inhibitors / Q000502:physiology*; D017450:Receptors, Opioid, mu / Q000037:antagonists & inhibitors / Q000502:physiology*; D013449:Sulfonamides / Q000494:pharmacology*
chemical_list: D000700:Analgesics; D052246:Cyclooxygenase 2 Inhibitors; D010880:Piperidines; D011720:Pyrazoles; D043884:Receptor, Cannabinoid, CB1; D017465:Receptors, Opioid, delta; D017450:Receptors, Opioid, mu; D013449:Sulfonamides; C103505:AM 251; D009271:Naltrexone; C024524:beta-funaltrexamine; D002351:Carrageenan; D051546:Cyclooxygenase 2; C055382:naltrindole; D000068579:Celecoxib