Effects of intrathecally administered nociceptin, an opioid receptor-like1 (ORL1) receptor agonist, on the thermal hyperalgesia induced by unilateral constriction injury to the sciatic nerve in the rat.

Abstract

Nociceptin is a 17 amino acid peptide which acts as a potent endogenous agonist of the opioid receptor-like1 (ORL1) receptor. In the spinal cord, nociceptin is reported to depress glutamatergic transmission and to block the spinally mediated facilitation which is thought to be mediated by the activation of N-methyl-D-aspartate (NMDA) receptor. It has been found that NMDA receptor mediated spinal facilitation is crucial in the maintenance of thermal hyperalgesia evoked by a nerve constriction injury. In the present study, we investigated the effect of intrathecally administered nociceptin on the level of thermal hyperalgesia after unilateral constriction injury to the sciatic nerve in the rat. Intrathecally administered nociceptin attenuated the level of thermal hyperalgesia in a dose dependent manner. These data indicate that spinal ORL1 receptor activation by nociceptin inhibits the spinal facilitation evoked by the nerve constriction injury.

• Authors: T Yamamoto, N Nozaki-Taguchi, S Kimura
• Journal: Neuroscience letters (Neurosci Lett) Vol. 224 Issue 2 Pg. 107-10 (Mar 14 1997) ISSN: 0304-3940 [Print] Ireland
• PMID: 9086468 (Publication Type: Journal Article)

Chemical References

• Opioid Peptides
• Receptors, N-Methyl-D-Aspartate
• Receptors, Opioid
• nociceptin
• Nociceptin Receptor
• Oprl protein, rat

Topics

• Animals
• Behavior, Animal (drug effects)
• Brain Chemistry (physiology)
• Dose-Response Relationship, Drug
• Hot Temperature
• Hyperalgesia (drug therapy, metabolism)
• Injections, Spinal
• Ligation
• Male
• Nociceptors (drug effects)
• Opioid Peptides (pharmacology)
• Rats
• Rats, Sprague-Dawley
• Receptors, N-Methyl-D-Aspartate (physiology)
• Receptors, Opioid (agonists)
• Sciatic Nerve (injuries, surgery)
• Nociceptin Receptor