Delta-opioid receptors are present in the superficial dorsal horn and are believed to regulate the release of small afferent transmitters. The present study examined the effects of intrathecal SNC80 [(1)-4-[α(R)-α-[(2S,5R)-4-allyl-2,5-dimethyl- 1-piperazinyl]-3-(methoxybenzyl)-N,N-diethylbenzamide], a selective nonpeptide delta-opioid receptor agonist in three preclinical pain models. Intrathecal SNC80 did not change acute thermal latencies or carrageenan-induced thermal hyperalgesia. However, SNC80 attenuated carrageenan-induced tactile allodynia and significantly reduced formalin-induced paw flinches. These effects were abolished by selective a delta-opioid antagonist but not by a mu-opioid antagonist. Furthermore, intrathecal SNC80 blocked substance P release from the ispilateral superficial dorsal horn. These data suggest that delta-opioid agonist alleviates pain hypersensitivity following peripheral inflammation.
See article at J Pharmacol Exp Ther 2013, 347:258–264.
- Copyright © 2013 by The American Society for Pharmacology and Experimental Therapeutics