Endogenous nociceptin signaling and stress-induced analgesia.
Neuroreport
; 12(14): 3009-13, 2001 Oct 08.
Article
in En
| MEDLINE
| ID: mdl-11568627
ABSTRACT
Nociceptin/orphanin FQ (NC) and its receptor (OP4) have been implicated in pain transmission. The aim of the present study was to investigate the role of the NC/OP4 system in stress-induced analgesia (SIA). The tail-withdrawal assay was performed in mice stressed by forced swimming in water at 15 degrees C (high severity swims) or 32 degrees C (low severity swims). High severity swims produced a naloxone-insensitive antinociceptive effect which was blocked by supraspinal NC (1 nmol). The selective OP4 receptor antagonist, [Nphe1]NC(-13)NH2 (30 nmol), was inactive by itself, but prevented the effect of NC. Low severity swims produced a milder analgesic effect that was partially antagonized by naloxone, completely blocked by NC and potentiated by [Nphe1]NC(-13)NH2. These findings confirm the anti-analgesic role of supraspinal NC and suggest that endogenous NC signaling counteracts the opioid component of SIA.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Pain
/
Stress, Physiological
/
Signal Transduction
/
Central Nervous System
/
Receptors, Opioid
/
Opioid Peptides
/
Analgesia
Limits:
Animals
Language:
En
Journal:
Neuroreport
Journal subject:
NEUROLOGIA
Year:
2001
Document type:
Article
Affiliation country:
Italy