盐酸布比卡因对大鼠神经病理性疼痛的早期阻滞作用

目的:探讨盐酸布比卡因对大鼠L₅脊神经结扎术(SNL)引起的神经病理性疼痛的早期阻滞作用。方法:雄性SD大鼠随机分为3组:L₅SNL组:包括L₅SNL手术组和L₅SNL假手术组;L₅脊神经背根切断术(DR)组:包括L₅DR联合L₅SNL组、L₅DR假手术联合L₅SNL组、L₅DR联合L₅SNL假手术组;L₅背根节(DRG)节外注射盐酸布比卡因组:包括L₅SNL术后L₅DRG节外盐酸布比卡因注射组或HEPES缓冲液注射组。采用von Frey丝测试各组大鼠术侧及对侧后肢足底L₄脊神经支配皮肤区域特异性的疼痛反应;用免疫荧光组织化学染色技术检测大鼠L₅脊髓节段Iba-1的表达。结果:L₅SNL术后大鼠术侧50%爪缩阈值(P...

Early blockade of bupivacaine hydrochloride for neuropathic pain in rats

Objective:To investigate the early blocking effects of bupivacaine hydrochloride on neuropathic pain induced by L5 spinal nerve ligation(SNL)in rat.Methods:Male SD rats were randomly divided into 3 groups:L5SNL group:including L5SNL and L5SNL sham;L5DR group:including L5 dorsal rhizotomy(DR)combined with L5SNL,L5DR sham combined with L5SNL and L5DR combined with L5SNL sham;L5 dorsal root ganglia(DRG)injection of bupivacaine hydrochloride group:including injection of bupivacaine hydrochloride and injection of HEPES buffer to L5DRG after L5SNL.For ipsilateral and contralateral rats hindpaws of each group,the von Frey hair behavior test method was used to detect the specific pain response of the skin area innervated by the L4 spinal nerve.The expression of Iba-1 in L5 spinal cord segment in rat was detected by immunofluorescence histochemincal technique.Results:After L5SNL,the ipsilateral 50%paw withdrawal threshold(PW T)of rats decreased(P<0.05)and was maintained until the 14 th day.The model,L5SNL,was successfully established.After the combined action of L5DR anti L5SNL,the ipsilateral 50%PWT of rats decreased(P<0.05),and its pain threshold level and time course were no difference with that of rats with L5SNL surgery alone.After L5SNL,the ipsilateral 50%PWT decreased(P<0.05)both in rats injected with bupivacaine hydrochloride or HEPES buffer to the L5DRG,but the reduction degree of bupivacaine hydrochloride injection group was lower than the HEPES buffer injection group(P<0.05).And the microglia were not activated in the 5th lumbar segment of the ipsilateral spinal cord in the bupivacaine hydrochloride injection group,showing no difference with normal animals as control(P>0.05)but difference with HEPES buffer injection group(P<0.05).Conclusion:L5DR cannot block or alleviate neuropathic pain caused by L5 spinal nerve injury in rats,while L5DRG injection of bupivacaine hydrochloride can effectively block the neuropathic pain behavioral response and the activation of microglia in corresponding spinal cord segment caused by spinal nerve injury in rats.