A型肉毒毒素抑制脑源性神经营养因子的表达减缓大鼠神经病理性疼痛

Type A botulinum toxin alleviates neuropathic pain in rats by inhibiting BDNF expression

目的探讨A型肉毒毒素通过抑制脊髓中脑源性神经营养因子(BDNF)的表达减缓大鼠神经病理性疼痛。方方法30只雄性SD大鼠随机分为3组:假手术+鞘内注射生理盐水组、慢性坐骨神经压迫损伤(CCI)造模+鞘内注射生理盐水组、CCI造模+鞘内注射0.1 U A型肉毒毒素组,每组10只。术前1 d及术后3、5、7、9、11、13、14 d观察鞘内注射A型肉毒毒素对大鼠患侧机械缩足反射阈值(MWT)的影响,术后第14天取各组大鼠脊髓腰膨大,检测BDNF的表达水平。结果与假手术+鞘内注射生理盐水组相比较,CCI造模+鞘内注射生理盐水组MWT显著下降(P<0.05),与CCI造模+鞘内注射生理盐水组相比较,鞘内注射A型肉毒毒素后,大鼠MWT明显升高(P<0.05)。鞘内注射A型肉毒毒素抑制了CCI损伤引起的大鼠脊髓BDNF表达上调。结论A型肉毒毒素通过抑制BDNF的表达减缓大鼠神经病理性疼痛。

Objective To investigate whether type A botulinum toxin alleviates neuropathic pain in rats by inhibiting the expression of brain-derived neurotrophic factor(BDNF)in the spinal cord.Methods Thirty male SD rats were randomly divided into three groups(n=10):the sham operation+intrathecal injection of normal saline group,sciatic nerve chronic constriction inury(CCI)+intrathecal injection of normal saline group,CCI+intrathecal injection of 0.1 U type A botulinum toxin group.The effects of intrathecal injection of type A botulinum toxin on the mechanical withdrawal threshold(MWT)of rats were observed on the 1st day before operation and 3 rd,5 th,7 th,9 th,11 th,13 th and 14 th days after operation.The lumbar spinal cord was taken out from different groups of rats after the surgery for 14 d,and the BDNF of lumbar spinal cord were measured.Results Compared with the sham operation+intrathecal injection of normal saline group,the MWT of CCI+intrathecal injection of normal saline group were significantly decreased(P<0.05),and compared with CCI+intrathecal injection of normal saline group,the MWT of rats increased after intrathecal type A botulinum toxin injection(P<0.05).In addition,intrathecal injection of type A botulinum toxin inhibited the up-regulation of BDNF levels in CCI-induced rats.Conclusion Type A botulinum toxin can alleviate neuropathic pain in rats by inhibiting BDNF expression.