PMID- 10780972
OWN - NLM
STAT- MEDLINE
DCOM- 20000630
LR  - 20181113
IS  - 0007-1188 (Print)
IS  - 0007-1188 (Linking)
VI  - 129
IP  - 8
DP  - 2000 Apr
TI  - Antihyperalgesic effects of delta opioid agonists in a rat model of chronic 
      inflammation.
PG  - 1668-72
AB  - Opioid receptors in the brain activate descending pain pathways to inhibit the 
      nociceptive response to acute noxious stimuli. The aim of the present study was 
      to clarify the role of supraspinal opioid receptors in modulating the nociceptive 
      response to persistent inflammation in rats. Subcutaneous administration of 50 
      microl of complete Freund's Adjuvant (CFA) into the plantar surface of the 
      hindpaw induced a significant decrease in paw withdrawal latency to thermal 
      stimuli (P<0.01) at 24 h post-injection. Intracerebroventricular (i.c.v.) 
      administration of the mu opioid receptor agonists, DAMGO and morphine, and the 
      delta opioid receptor agonists, deltorphin II and SNC80, significantly reversed 
      the hyperalgesic response associated with peripheral inflammation in a 
      dose-dependent manner (P<0.0001). The mu and delta agonists also significantly 
      attenuated the antinociceptive response to acute thermal stimulation in rats 
      (P<0.001). However, deltorphin II and SNC80 were less potent, and in the case of 
      SNC80 less efficacious, in modulating the response to acute thermal nociception 
      in comparison to hyperalgesia associated with persistent inflammation. These 
      results indicate that mu and delta opioid receptors in the brain modulate 
      descending pain pathways to attenuate the nociceptive response to acute thermal 
      stimuli in both normal and inflamed tissues. The heightened response to delta 
      agonists in the hyperalgesia model suggests that delta opioid receptors in the 
      brain are promising targets for the treatment of pain arising from chronic 
      inflammation.
FAU - Fraser, G L
AU  - Fraser GL
AD  - AstraZeneca R&D Montreal, H4S 1Z9 Canada.
FAU - Gaudreau, G A
AU  - Gaudreau GA
FAU - Clarke, P B
AU  - Clarke PB
FAU - Menard, D P
AU  - Menard DP
FAU - Perkins, M N
AU  - Perkins MN
LA  - eng
PT  - Journal Article
PL  - England
TA  - Br J Pharmacol
JT  - British journal of pharmacology
JID - 7502536
RN  - 0 (Narcotics)
RN  - 0 (Receptors, Opioid, delta)
RN  - 0 (Receptors, Opioid, mu)
RN  - 9007-81-2 (Freund's Adjuvant)
SB  - IM
MH  - Animals
MH  - Disease Models, Animal
MH  - Freund's Adjuvant
MH  - Hyperalgesia/chemically induced/*physiopathology
MH  - Male
MH  - Narcotics/chemistry/*pharmacology/therapeutic use
MH  - *Pain
MH  - Pain Measurement
MH  - Rats
MH  - Rats, Sprague-Dawley
MH  - Receptors, Opioid, delta/agonists/*physiology
MH  - Receptors, Opioid, mu/agonists
PMC - PMC1572005
EDAT- 2000/04/26 09:00
MHDA- 2000/07/08 11:00
PMCR- 2001/04/01
CRDT- 2000/04/26 09:00
PHST- 2000/04/26 09:00 [pubmed]
PHST- 2000/07/08 11:00 [medline]
PHST- 2000/04/26 09:00 [entrez]
PHST- 2001/04/01 00:00 [pmc-release]
AID - 0703248 [pii]
AID - 10.1038/sj.bjp.0703248 [doi]
PST - ppublish
SO  - Br J Pharmacol. 2000 Apr;129(8):1668-72. doi: 10.1038/sj.bjp.0703248.