蛛网膜下腔注射pcDNA3.1(+)-hPPE对大鼠神经病理性痛的镇痛效应

Objective: To observe the analgesic effect of intrathecal injection of pcDNA3.1(+)-hPPE recombinant plasmid on neuropathic pain in rats. Methods: Sprague-Dawley rats were randomly divided into four groups: chronic constriction injury of the sciatic nerve (CCI) group, sham-operated group. pcDNA3.1(+)-hPPE group and pcDNA3.1(+) group. The CCI group and the sham-operated group were designed for the observation of pain behavior duration. The pcDNA3.1(+)-hPPE recombinant plasmid and the eukaryotic expression vector pcDNA3.1 (+) was intrathecally injected at a dose of 30 μg/100 μl at day 15 after CCI operation in the two groups. The paw withdrawal thermal latency (PWTL) was examinated before and after CCI operation. The effect of naloxone was tested; the concentrations of enkephalin in cerebrospinal perfusion fluid were measured with radioimmunoassay and the changes in NR2B protein expression in the spinal cord dorsal horn was detected with immunohistochemical techniques in both groups at day 18 after intrathecal injection. Results: 7-33 days after CCI. PWTL was significantly lower than that of the contralateral sides. There was no significant difference in PWTI, in the pcDNA3.1(+) group after intrathecal injection at any test time; The right PTWI, was significantly higher than that of the left PTWL in the pcDNA3.1(+)-hPPE group from 2 to 18 days after intrathecal injection. The attenuation of the thermal hyperalgesia induced by CCI in the rats could be blocked by naloxone. The concentrations of the leucine enkephalin in CSF of the pcDNA3.1(+)-hPPE group were significantly higher than those in CSF of the pcDNA3.1(+) group. The expression of NR2B protein was significantly decreased in the spinal cord dorsal horn in the pcDNA3.1 (+)-hPPE group. Conclusion: The pcDNA3.1(+)-hPPE recombinant plasmid transfecting into the soharachnoid space of CCI model rats via intrathecal injection may significantly attenuate thermal hyperalgesia.