EFFECT OF INTRATHECAL KETAMINE ON THE EXPRESSION OF NR2B mRNA IN THE SPINAL CORD OF CCI RATS

Objective:To evaluate the effect of intrathecal ketamine on the expression of NR2B mRNA in the spinal dorsal cord of CCI rats.Methods: Eighteen male Sprague-Dawley rats were randomly divided into 3 groups: In groupⅠthe animals were shamly operated;In group Ⅱ(CCI) the rats were placed four loose ligatures around the right sciatic nerve;In group Ⅲ(CCI+KET) of ketamine 1mg/kg was administered 30min before and 1,2,3,5,7,9,11 days after operation.Rats were tested for hyperalgesia by measuring paw withdrawal latency(PWL) using von-Frey filaments and ice-cold water.The changes in NR2B mRNA expression in the spinal cord were detected by hybridization in situ technique.Results: The expression of NR2B mRNA was minimal in sham operation group;CCI induced significant increase in the expression of NR2B mRNA in the ipsilateral spinal cord(P0.01),ketamine i.t.significantly inhibited the increase in NR2B mRNA expression(P0.01).Conclusion: Upregulation of NR2B expression may be involved in the development of neuropathic pain,and inhibition of NR2B expression may contribute to the antinociceptive effects of ketamine.