内降钙素基因相关肽和μ阿片受体在腰椎间盘突出模型大鼠脊髓后角内的表达

摘要

目的 利用椎间孔内置管模拟椎间盘突出压迫脊神经根,观察模型鼠脊髓后角内降钙素基因相关肽(CGRP)和μ阿片受体(MOR)的表达,探讨腰椎间盘突出后致腰腿疼发生的可能机制.方法 将18只SD大鼠随机分为模型组和对照组,模型组在大鼠椎间孔内置管,模拟腰椎间盘突出压迫脊神经根;对照组在大鼠椎间孔插管后旋即拔出.于术前、术后分别观察大鼠行为;采用足底力学感觉测量仪测定大鼠后肢机械痛阈,热板测痛仪测定大鼠左后足底的热刺激感受阈值;免疫荧光组织化学法观察CGRP和MOR在脊髓后角的形态学特点;Western blot检测CGRP和MOR在脊髓内的表达.结果 模型组大鼠后肢运动受限,对照组于术后第7天基本恢复正常;术后第1、3和7天模型组的机械痛阈值和热痛阈值均小于同时间点对照组(P均＜0.05);免疫荧光发现CGRP和MOR蛋白均表达于脊髓后角,且经Western blot检测发现CGRP含量模型组较对照组升高,而MOR蛋白含量模型组较对照组降低.结论 腰椎间盘突出模型大鼠脊髓背角内CGRP和MOR蛋白表达改变,可能为腰椎间盘突出症腰腿痛的机制之一.%ObjectiveTo observe the expression of calcitonin gene-related peptide (CGRP) andμopioid receptor (MOR) in the posterior horn of the spinal cord using the intervertebral foramen to simulate the intervertebral disc herniation, and then explores the possible mechanism of the occurrence of lumbar leg pain during lumbar disc herniation.Methods Eighteen SD rats were randomly divided into control group and model group.In the model group, a canal was inserted into the intervertebral foramen to simulate the compression of the spinal nerve root by lumbar disc herniation, in the control group, the cannula was inserted into the intervertebral foramen and then pulled out.Behavior of rats was observed before and after operation, mechanical pain threshold of hind limbs was measured by plantar mechanical sensory meter, thermal stimulation threshold of left hind plantar was measured by hot plate pain meter, morphological characteristics of CGRP and MOR in the posterior horn of spinal cord were observed by immunofluorescence histochemistry, CGRP and MOR expression in spinal cord were detected by Western blot.Results Compared with control group, the hind limb movement was restricted in the model group at day 7 after operation.Simultaneously, the threshold of mechanical pain and thermal pain in the model group was significantly lower than those of the control group at1d, 3d and 7d after operation (P＜0.05).The results of immunofluorescence showed that CGRP and MOR expressed in the posterior horn of spinal cord.According to Western blot, the expression of CGRP in the model group was higher than control group, while the content of MOR was lower than the control group.ConclusionThe expression change of CGRP and MOR in spinal dorsal horn of rats with lumbar disc herniation is probably the mechanism of lumbar and leg pain in lumbar disc herniation.