Anti-allodynic Efficacy of NMDA Antagonist Peptide and Noradrenaline Alone and in Combination in Rodent Neuropathic Pain Model.

Abstract

BACKGROUND:

The present experiment was conducted to identify the cooperative effect of serine histogranin (SHG) and noradrenaline in alleviating peripheral neuropathic pain.

METHODS:

Chronic constriction injury of the right sciatic nerve was used to induce chronic neuropathic pain. For drug delivery, a PE10 tube was inserted into the subarachnoid space. Acetone drops and a 44℃ water bath were used to evaluate the cold and heat allodynia, respectively. Placing and grasping reflexes were used to assess the locomotor system.

RESULTS:

SHG at 0.5 and 1 µg significantly (P < 0.05) decreased the thermal allodynia. The cold allodynia was also significantly reduced by intrathecal injections of 0.5 (P < 0.05) and 1 µg (P < 0.001) of SHG. 1 µg of noradrenaline, but not 0.5 µg, significantly alleviated the cold (P < 0.01) and thermal (P < 0.05) allodynia. The ameliorating effect of noradrenaline or SHG disappeared when the two compounds were administrated in equal concentrations. A significant difference (P < 0.01 in the acetone and P < 0.05 in the heat) was observed in the groups under equal doses of the two compounds, with a lower effectiveness of the combination therapy.

CONCLUSIONS:

Our findings suggest that the simultaneous administrations of noradrenaline and SHG do not result in synergistic analgesia, and combination therapy may not be a good approach to the treatment of chronic neuropathic pain syndrome.

• Authors: Farinaz Nasirinezhad, Marjan Hosseini, Sajad Salari
• Journal: The Korean journal of pain (Korean J Pain) Vol. 28 Issue 2 Pg. 96-104 (Apr 2015) ISSN: 2005-9159 [Print] Korea (South)
• PMID: 25852830 (Publication Type: Journal Article)