椎间盘源性腰痛神经传入通路的实验研究

Experimental study on nerve conduction pathways of discogenic low back pain

目的通过椎间盘内注入外源性炎性因子白细胞介素-1β(interleukin-1β,IL-1β)分别选择性切断L3及L5交感干,对交感神经在椎间盘痛觉传导通路中作用进行研究。方法实验以20只Wistar大鼠为研究对象,随机平均分为2组,10只切断双侧L3交感干(L3椎体上缘相应水平的交感链),10只切断双侧L5交感干(L5椎体上缘相应水平的交感链),皆为自身对照,切断前为对照数据。通过L5/L6椎间盘后侧注入外源性炎性因子IL-1β,分别选择性切断L3交感干及L5交感干,监测切断前后L1～5脊神经节动作电位的幅度和潜伏期,用统计学方法对切断前后各指标进行检验,观察交感干切断后对椎间盘痛觉传导通路的影响。结果切断双侧L3交感干后大鼠L1,2脊神经动作电位的幅度减弱,潜伏期延长,其差别有统计学意义(P<0.05)。切断双侧L5交感干后大鼠L1～4脊神经动作电位的幅度减弱,潜伏期延长,其差别有统计学意义(P<0.05)。结论交感干在腰椎椎间盘痛觉传导通路中起重要的作用。L3交感干和L5交感干在L5/L6椎间盘痛觉传导通路中的作用不同。L5交感干在L5/L6椎间盘至L1,2脊神经节的痛觉传导通路中起重要作用。L5/L6椎间盘后侧至上腰椎的传导通路与L3交感干有关,而至下腰椎的痛觉传导通路与L3交感干无关。

Objective To study the role of sympathetic nerves on the conduction of discogenic low back pain by intradiscal injection of exogenous inflammatory cytokines interleukin-1β（IL-1β）,via selective cutting off the bilateral sympathetic trunks distal to L3 and L5 sympathetic ganglions respectively.Methods Twenty Wistar rats were randomly divided into 2 groups in which bilateral L3 and L5 sympathetic trunks distal to L3 and L5 sympathetic ganglions were cut off respectively.Before sympathetic trunks were cut off,L5/L6 intradiscal injection of exogenous inflammatory cytokines IL-1β was performed in all rats.The action potential amplitude and latency of spinal nerves were monitored with the use neuroelectrophysiological method before and after cutting off sympathetic trunks.Results The action potential amplitudes of L1,2 nerve roots decreased,and the latency extended obviously after cutting off bilateral L3 sympathetic trunk compared with those before cutting off.The differences are statistically significant（P0.05）.The action potential amplitudes of L1-4 nerve roots decreased,and the latency extended obviously after cutting off bilateral L5 sympathetic trunk compared with those before cutting off.The differences also are statistically significant（P0.05）.Conclusion Sympathetic trunk has some effects on the nociceptive pathway of lumbar intervertebral disc.The effect of L3 Sympathetic trunk on the nociceptive afferent pathway of L5/L6 disc is different from that of L5 Sympathetic trunk.L5 sympathetic trunk has some effects on the nociceptive pathway of L5/L6 disc to L1/L2 spinal ganglion.L3 Sympathetic trunk is related with the nociceptive pathway of L5/L6 disc to Upper lumbar spine,but it is not related with the nociceptive pathway of L5/L6 disc to Lower lumbar spine.