Effect of intrathecal Butorphanol on rats′ changes of NMDAR1 mRNA and MOR mRNA expression in rat spinal following neuropathic pain

Objective: To observe the effect of intrathecal Butorphanol on rats′ changes of NMDAR1 mRNA and MOR mRNA expression in rat spinal following neuropathic pain and explore the possible mechanisms of Butorphanol treat neurathic pain. Methods: Twenty-four healthy mail Sprague-Dawley rats weight(250±20) g were randomly devided into three groups (n=8,in each group), control group (group B), normal saline group (group C)and Butorphanol group(group T). Group B weren′t given any treatment. Microapinal catheters were insterted intrathecally into the rest rats′ lumbar region succeefully and made the chronic constriction injury (CCI). Group C were intrathecally injected NS 10 μl.Group T were intrathecally in- jected Butorphanol 12 μg/10 μl (Diluted with NS). After seven days, all rats were killed, remove the spinal cord speci- mens. Using RT-PCR method to determine the expression level of NMDAR1 mRNA and MOR mRNA. Results:The ex- pression level of NMDAR1 mRNA, Compared to group B, the expression level of group C was higher, P0.01, and group T was lower than group C.The expression of MOR mRNA, there was no significant differences between three groups. Conclusion: Intrathecal injection of butorphanol can reduce the expression level of NMDAR1 mRNA increase in rat spinal cord which caused by the CCI model,and the expression level of MOR mRNA has no significant changes. After CCI model the expression of MOR mRNA level returned to normal within 12 days.