Effect of repeatedly intrathecal butorphanol on spinal FOS expression in a rat with neuropathic pain

Objective To investigate the effects of repeatedly intrathecal butorphanol on spinal Fos expression in a rat with neuropathic pain. Methods Thirty Sprague-Dawley rats were randomly divided into 3 groups : Control group (C), model group (M) and butorphanol group (B). Micro-catheter were implanted in spinal space. CCI was produced by placing 4 loose ligatures on the sciatic nerve at 1 mm intervals with 4-catgnt. Five days after operation, rats from group M and group B were intrathecally administered butorphanol ( 12μg/10μL) for 7 days. On the 12th day, the lumbar segment of spinal cord was removed for determination of the expression of Fos by immunohistochemistry. Results Micro-catheter were pulled out in 2 rats in group B. Compared with group C, the number of FLI neurons was significantly increased in group M and B. The expression of c-los in group M was significantly higher than those in group B. Conclusions Repeatedly intrathecal butorphanol significantly inhibited the increase of Fos expression in the spinal dorsal horn of CCI, suggesting repeatedly intrathecal betorphanol may be a possible way to treat neuropathic pain. Key words: Butorphanol/AD;  Pain/DT/ET;  Nervous system diseases/CO;  Proto-oncogene proteins c-los/ME ;  Injection;  spinal