Authors: Esther Berrocoso M Olga RojasCorrales Juan A Mico
Publish Date: 2006/07/11
Volume: 188, Issue: 1, Pages: 111-118
Abstract
Tramadol 1RS2RS2dimethylaminemethyl13methoxyphenylcyclohexanol hydrochloride is an atypical analgesic which binds weakly to ìopioid receptors and enhances the extraneuronal concentration of noradrenaline and serotonin by interference with both the uptake and release mechanismsThe effect of either a selective 5HT1A receptor antagonist WAY 100635 N242methoxyphenyl1piperazinylethylN2pyridinylcyclohexane carboxamide 02–08 8 mg/kg or a selective 5HT1B receptor antagonist SB 216641 N33dimethylamino ethoxy4methoxyphenyl2′methyl4′5methyl124oxadiazol3yl11′biphenyl4carboxamide 02–08 8 mg/kg was investigated in mice in combination with tramadol by means of the hotplate test a phasic nociceptive model and the forced swimming test a paradigm aimed at screening potential antidepressantsThe results showed that WAY 100635 enhanced the antinociceptive effect and produced a large decrease in the antidepressantlike effect of tramadol In contrast SB 216641 did not significantly modify either the analgesic or the antidepressantlike effects of tramadolThese findings suggest that 5HT1A receptors modulate the analgesic and the antidepressantlike effects of tramadol in differing ways The results suggest the involvement of the 5HT1A autoreceptors from the raphe nuclei and spinal 5HT1A receptors in the antinociceptive effect In contrast the 5HT1A receptors located in the forebrain may be responsible for the blockade of the antidepressantlike effect of tramadol 5HT1B receptors seem not to modify these effects in the models investigated
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