Analgesic profile of the nicotinic acetylcholine receptor agonists, (+)-epibatidine and ABT-594 in models of persistent inflammatory and neuropathic pain.
The anti-nociceptive and locomotor effects of the nicotinic acetylcholine receptor (nAChR) agonists (+)-epibatidine and ABT-594 were compared in the rat. Acute thermal nociception was measured using the tail flick test. Mechanical hyperalgesia was measured as paw withdrawal threshold (PWT) in response to a mechanical stimulus in two animal models of persistent pain; (1) 24 h following subplantar injections of Freund's complete adjuvant (FCA) into the left hind paw or (2) 11-15 days following a partial ligation of the left sciatic nerve. Disruption of locomotor function was assessed using an accelerating rotarod device. In all tests, (+)-epibatidine was significantly more potent than ABT-594. Both (+)-epibatidine and ABT-594 dose-dependently increased tail flick latencies but only at doses that also disrupted performance in the rotarod test. On the other hand, (+)-epibatidine and ABT-594 dose-dependently reversed inflammatory and neuropathic hyperalgesia at significantly lower doses than that needed to disrupt performance in the rotarod test. In summary, ABT-594 is less potent than (+)-epibatidine in assays of acute and persistent pain and in the rotarod assay. However, ABT-594 displayed a clearer separation between its motor and anti-hyperalgesic effects. This shows that nicotinic agonists with improved selectivity between the nicotinic receptor subtypes could provide strong analgesic effects with a much improved therapeutic window.[1]References
- Analgesic profile of the nicotinic acetylcholine receptor agonists, (+)-epibatidine and ABT-594 in models of persistent inflammatory and neuropathic pain. Kesingland, A.C., Gentry, C.T., Panesar, M.S., Bowes, M.A., Vernier, J.M., Cube, R., Walker, K., Urban, L. Pain (2000) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg