Pathomechanism of radicular pain in lumbar radiculopathy.

将脂肪、髓核（NP）和纤维环（AF）异体移植至大鼠L_6水平硬膜外腔。术后对机械刺激的戒断反应阈值和对热刺激的戒断反应潜伏期。应用免疫组织化学、NADPH-diaphorase组织化学和原位杂交技术检测各组组织中白细胞介素-1、PLA_2和NOS的表达。结果表明，同种异体移植的脂肪不会产生痛觉过敏。NP和NP+AF异体移植物分别表现出机械痛觉过敏和热痛觉过敏。白细胞介素-1在所有应用组织中均可见，PLA_2仅在应用NP和NP+AF周围可见。NOS仅在施药前后显著升高。分别采用NP组（同种异体NP放置于坐骨神经上）和NP+AF组（NP+AF）对手术部位局部坐骨神经给予L-NAME或甲哌辛后对有害刺激的敏感性进行评价。只有NP组大鼠表现出机械性痛觉过敏。注射L-NAME导致NP+AF组出现机械性痛觉过敏。机械性痛觉过敏，NP组和NP+AF组分别在注射L-NAME后产生，注射甲哌辛后恢复正常。综上所述，PLA_2和NO在腰椎间盘突出症神经根性疼痛的发病机制中发挥重要作用，但作用不同。

Fat, nucleus pulposus (NP) and anulus fibrosus (AF) were allografted into the epidural space at L_6 level in the rat. Withdrawal response thresholds to mechanical stimuli and withdrawal response latencies to thermal stimuli on the tail postoperatively. Interleukin-1, PLA_2 and NOS were examined in the applied tissues using immunohistochemistry, NADPH-diaphorase histochemistry and in situ hybridization. In results, allografted fat did not produce hyperalgesia. Allografts of NP and NP+AF showed evidence of mechanical and thermal hyperalgesia, respectively. Although interleukin-1 was demonstrated in all applied tissues, PLA_2 was only observed around the applied NP and NP+AF.NOS was only markedly increased around the applied. The NP group (allografted NP placed on the sciatic nerve) and NP+AF group (NP+AF,respectively) were mede to evaluate the sensitivities to noxious stimuli following local sciatic nerve administration of L-NAME or mepacrine into the operated site. Only rats in the NP group showed evidence of mechanical hyperalgesia. Injection of L-NAME resulted in evidence of mechanical hyperalgesia in the NP+AF group. Mechanical hyperalgesia, which was produced in the NP group and after injection of L-NAME in the NP+AF group, both of which returned to normal after mepacrine injection. In conclusion, it appears that PLA_2 and NO play important but different roles in pathomechanisms of radicular pain in lumbar disc herniation.