针刺对腰椎间盘突出症大鼠模型痛行为和脊神经根组织形态学的影响

Influences of electro-acupuncture on pain-related behaviors and histomorphological changes of spinal nerve root in rat model of lumbar disc herniation

目的建立腰椎间盘突出症大鼠模型,观察针刺对其痛行为及神经根和背根神经节形态学变化的影响。方法雄性SD大鼠36只,随机分为4组:正常对照组、模型组、假手术组和针刺组,每组9只,采用自体髓核移植法建立腰椎间盘突出症大鼠模型。针刺组电针双侧腰4、5"夹脊穴"、"大肠俞"、"关元俞"、"委中"和"昆仑",每日1次,每次20 min,连续治疗7 d。治疗结束后,观察大鼠行为学变化,测定机械缩爪阈,应用HE染色方法检测脊神经根及背根神经节形态变化。结果模型组术后3 d出现痛觉过敏,与假手术组和正常对照组比较有极显著差异(P<0.01),痛阈降低持续至术后7 d。针刺组痛阈较模型组有显著上升,术后3 d最为明显,与模型组比较有极显著差异(P<0.01),术后7 d有显著差异(P<0.05)。HE染色结果显示模型组神经根术和背根神经节术后3 d出现炎性水肿,并且逐渐加重,术后7 d神经纤维髓鞘崩解及坏死,神经节胞浆出现空泡样改变,细胞核部分消失。与模型组比较,针刺组神经根及背根神经节水肿及坏死程度减轻。结论腰椎间盘突出症大鼠模型建立成功,针刺减轻脊神经根和背根神经节损伤程度。

Objective To establish a rat model of lumbar disc herniation （LDH）,and observe the influences of electro-acupuncture （EA） on pain-related behaviors and histomorphological changes of spinal nerve root and dorsal root ganglion （DRG）.Methods Male SD rats （n =36） were randomly divided into normal group,model group,sham-operation group and EA group （each n =9）.The rat model of LDH was established by using autologous grafting of nucleus pulposus.EA group was treated with EA in Jiaji （EX-B2）,Dachangshu （BL25）,Guanyuanshu （BL26）,Weizhong （BL40） and Kunlun （BL60） of bilateral L4 and L5 once a day and 20 min once for 7 d.After treatment,the changes of rat behaviors were observed and mechanical withdrawal threshold was detected.The morphological changes of spinal nerve root and DRG were detected after HE staining.Results The hyperalgesia was observed in model group 3 d after the operation and the difference was greatly significant compared with sham-operation group and normal group（P 〈0.01）,and the decrease of pain threshold was lasted for 7 d.The pain threshold increased significantly in EA group especially after the operation for 3 d （P 〈 0.01） and after the operation for 7 d （P 〈 0.05） compared with model group.HE staining results showed that spinal nerve root and DRG had inflammatory edema 3 d after the operation and gradually exacerbated in model group,and after 7 d,disintegration and necrosis of nerve myelin sheath,vacuole-like change in cytoplasm of nerve ganglion cells and disappearing of some nucleus were observed in model group.The degree of edema and necrosis of spinal nerve root and DRG was reduced in EA group compared with model group.Conclusion The rat model of LDH is established successfully,and EA can relieve the damage of spinal nerve root and DRG.