大鼠腰5背根神经节束膜切开后自体髓核移植---一种改良非压迫性腰椎间盘突出症模型的建立

摘要：背景：椎间盘髓核的致炎特性是腰椎间盘突出症神经痛的重要机制，大鼠腰4、腰5半椎板切除术和并在左腰4、腰5神经根覆盖自体尾椎椎间盘髓核是研究非压迫性腰椎间盘髓核突出症常用的动物模型（简称传统模型）。但该模型尚存在创伤较大、成模率不高的不足。目的 ：只暴露左L5 背根神经节(Dorsal root ganglion, DRG)，行束膜切开后自体髓核移植制备非压迫性腰椎间盘髓核突出症改良模型，与传统模型比较其创伤度和成模率。方法 : 30只SD 雄性大鼠，随机分成三组，假手术组（6只），传统组（12只）、和改良组（12只）。统计每组的出血量和手术时间；测量术前1天和到术后大鼠的左后肢机械刺激缩爪阈值（paw withdrawal Threshold，PWT），和热刺激撤足潜伏期（paw withdrawal latency，PWAL）。结果：改良组手术时间和出血量少于传统模型组，改良组成模率91.7%高于传统组的58.3%，组间比较有统计学差异（p<0.05）。三组均未出现PWAL的减少。假手术组术后未出现PWT的降低。改良组和传统组术后出现明显的PWT降低（机械痛敏），改良组的机械痛敏比传统组更持久（28天VS 21天）。结论：对大鼠腰5背根神经节的束膜切开后再进行髓核移植可以制备损伤更小、疼痛行为学稳定的非压迫性腰椎间盘突出症的改良动物模型。

Autologous nucleus pulposus transplantation to lumbar 5 dorsal root ganglion after epineuriumetomy in rats: a modified model of non-compressive lumbar herniated intervertebral disc

Background: Nucleus pulposus of intervertebral discs has proinflammatory characteristics that play a key role in neuropathic pain in lumbar herniated intervertebral disc. One of the most commonly used animal models (the traditional model) of non-compressive lumbar herniated intervertebral disc is created by L4-L5 hemilaminectomy and the application of autologous nucleus pulposus to cover the left L4 and L5 nerve roots in rats. However, such procedures have the disadvantages of excessive trauma and low success rate. Purpose: We proposed a modified model of non-compressive lumbar herniated intervertebral disc in which only the left L5 dorsal root ganglion is exposed and transplanted with autologous nucleus pulposus following epineuriumetomy. We aimed to compare the modified model with the traditional one with regard to trauma and success rate. Methods: Thirty Sprague-Dawley male rats were randomized into three groups: sham operation group (n=6), traditional group (n=12), and modified group (n=12). The amount of blood loss and operative time for each group were analyzed. The paw withdrawal threshold of the left hind limb to mechanical stimuli and paw withdrawal latency to heat stimuli were examined from the day before surgery to day 35 after surgery. Results: Compared with the traditional group, the modified group had shorter operative time, smaller amount of blood loss, and higher success rate (91.7% versus 58.3%, p<0.05). There was no decrease in paw withdrawal latency in any group. The sham operation group had no decrease in postoperative paw withdrawal threshold,, whereas the modified and traditional groups had significant reduction in paw withdrawal threshold after surgery (mechanical hyperalgesia). Conclusions: Transplantation of nucleus pulposus onto the L5 dorsal root ganglion following epineuriumetomy in rats established an improved animal model of non-compressive lumbar herniated intervertebral disc with less trauma and more stable pain ethology.