Opioid receptors and acetaminophen (paracetamol).
We report that the acetaminophen (paracetamol)-induced spinal (intrathecal, i.t.)/supraspinal (intracerebroventricular, i.c.v.) site/site antinociceptive 'self-synergy' in mice is attenuated by the opioid receptor subtype selective antagonists beta-funaltrexamine hydrochloride (beta-FNA; mu), naltrindole (delta), and nor-binaltorphine hydrochloride (nor-BNI; kappa). These findings further implicate endogenous opioids (viz., endorphins, enkephalins, and dynorphins) and their pathways as contributors to the central antinociceptive action of acetaminophen.
Raffa
Robert B
RB
Department of Pharmaceutical Sciences, Temple University School of Pharmacy, 3307 North Broad Street, Philadelphia, PA 19140, USA. robert.raffa@temple.edu
Walker
Ellen A
EA
Sterious
Steven N
SN
D000082:Acetaminophen / Q000008:administration & dosage / Q000494:pharmacology*; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D004399:Dynorphins / Q000502:physiology; D004723:Endorphins / Q000502:physiology; D004745:Enkephalins / Q000502:physiology; D007276:Injections, Intraventricular; D007278:Injections, Spinal; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009271:Naltrexone / Q000031:analogs & derivatives* / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D011957:Receptors, Opioid / Q000187:drug effects*; D017465:Receptors, Opioid, delta / Q000037:antagonists & inhibitors; D017473:Receptors, Opioid, kappa / Q000037:antagonists & inhibitors; D017450:Receptors, Opioid, mu / Q000037:antagonists & inhibitors
D018712:Analgesics, Non-Narcotic; D004723:Endorphins; D004745:Enkephalins; D009292:Narcotic Antagonists; D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu; D000082:Acetaminophen; C051844:norbinaltorphimine; D009271:Naltrexone; C024524:beta-funaltrexamine; D004399:Dynorphins; C055382:naltrindole