所属 埼玉医科大学 医学部 総合医療センター 麻酔科（麻酔科、産科麻酔科） 職種 教授
|Antihyperalgesic effect of duloxetine and amitriptyline in rats after peripheral nerve injury: Influence of descending noradrenergic plasticity
|ELSEVIER IRELAND LTD
|Hajime Hoshino,Hideaki Obata,Shigeru Saito
|Antidepressants such as serotonin-noradrenaline reuptake inhibitors (SNRIs) and tricyclic antidepressants (TCAs) are frequently used for the management of neuropathic pain. Noradrenaline (NA) and serotonin (5-HT) increase in the spinal cord by reuptake inhibition is considered to be main mechanism of the therapeutic effect of antidepressants in neuropathic pain. In the present study, we examined the analgesic effects of duloxetine (SNRI) and amitriptyline (TCA) in a rat model of neuropathic pain induced by spinal nerve ligation (SNL). Intraperitoneal administration of duloxetine and amitriptyline dose-dependently (3,10 and 30 mg/kg) suppressed hyperalgesia induced by SNL. In vivo microdialysis in the lumbar spinal dorsal horn revealed that NA and 5-HT concentrations increased after intraperitoneal administration of duloxetine and amitriptyline (10 mg/kg, respectively). We further determined NA and 5-HT contents in homogenizedsamples from the ipsilateral dorsal spinal cord after SNL Although the NA content in SNL rats 2 weeks after ligation was higher than that in SNL rats 4 weeks after ligation, the analgesic efficacy of duloxetine and amitriptyline was similar between two groups.