TITLE

Role of serotonin 5-HT1A and opioid receptors in the antiallodynic effect of tramadol in the chronic constriction injury model of neuropathic pain in rats

AUTHOR(S)
Berrocoso, Esther; De Benito, M. Dolores; Mico, Juan A.
PUB. DATE
July 2007
SOURCE
Psychopharmacology;Jul2007, Vol. 193 Issue 1, p97
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Tramadol (1 RS, 2 RS)-2-[(dimethylamino)-methyl]-1-(3-methoxyphenyl)-cyclohexanol) is an atypical centrally acting analgesic agent with weak opioid receptor affinity that, like some antidepressants, enhances the extraneuronal concentrations of the monoamine neurotransmitters, noradrenaline and serotonin, by interfering with their re-uptake and release mechanisms. The present study was undertaken to evaluate the potential role of 5-HT1A receptors and opioids receptors in the analgesic effect of tramadol in neuropathic pain. With this aim, the effect of either a selective 5-HT1A receptor antagonist (WAY-100635, N-2-[4-(2-methoxyphenyl-1-piperazinyl]ethyl]- N-2-pyridinylcyclohexane carboxamide) or a selective 5-HT1A receptor agonist (8-OH-DPAT, 8-hydroxy-2-(di- n-propylamine) tetralin hydrobromide) or an opioid receptor antagonist (naloxone; naloxone hydrochloride dihydrate) was investigated in combination with tramadol by means of the cold-plate test in the chronic constriction injury model in rats. The results showed that WAY-100635 (0.8 mg/kg) significantly enhanced the antiallodynic effect of non-effective doses of tramadol (5–10 mg/kg). In contrast, 8-OH-DPAT (0.5 mg/kg) counteracted the antiallodynic effect of an effective dose of tramadol (22 mg/kg). Naloxone (0.5 mg/kg) partially counteracted the antiallodynic effect of tramadol (22 mg/kg). These findings suggest the involvement of opioid and 5-HT1A receptors in the antinociceptive effect of tramadol and support the idea that the combination of tramadol with compounds having 5-HT1A antagonist properties could be a new strategy to improve tramadol-induced analgesia in neuropathic pain.
ACCESSION #
25353477

 

Related Articles

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics