中文摘要：

目的：脊椎间盘突出、椎间孔狭窄、脊髓损伤以及肿瘤造成的背根节（dorsal root ganglion，DRG）及其邻近神经根的机械性压迫可能是引起腰背痛与坐骨神经痛的重要原因。临床上多节段神经根性痛比单一神经根性痛更常见，患者表现出多节段神经根压迫和多节段椎间孔狭窄。为此，本实验观察了多节段DRG慢性压迫大鼠的痛行为。方法：实验在本室创建的大鼠背根节慢性压迫（chronic compression of DRG，CCD）模型基础上采用单侧L3—5多节段DRG慢性压迫模型，应用von Frey细丝和丙酮分别检测机械触刺激诱发痛阈值和冷刺激诱发痛反应级别及反应百分数。结果：多节段DRG慢性压迫大鼠表现明显双侧机械触刺激诱发痛和冷刺激诱发痛行为，伴随明显延迟的对侧机械触刺激和冷刺激诱发痛的镜像痛行为。组织学观察显示多节段DRG慢性压迫同侧DRG内部及其神经根有明显炎症反应。结论：机械性压迫和炎症共同作用神经根和DRG导致多节段DRG慢性压迫大鼠明显的机械触刺激诱发痛和冷刺激诱发痛行为。

英文摘要：

Objectives： Mechanical deformation of the dorsal root ganglion （DRG） and its nerve roots nearby are possible consequences of low back pain and sciatica, resulted from disc herniation, spinal stenosis, spinal injury or tumors. Multilevel lumbosacral radiculopathies are more common than single level radiculopathies in clinics, and patients exhibit multilevel nerve root compression and intervertebral foraminal stenosis. Thus, pain behaviors were examined in chronically compressed multiple DRG rats. Methods： On the basis of a previously estabalished chronic compression of DRG in the rat in the lab, the rat model of unilateral compression of multiple DRGs was used in the present study. The mechanical threshold of tactile allodynia and response score and frequency of cold allodynia were examined with von Frey filaments and acetone respectively. Results： Both ipsilateral and contralateral mechanical thresholds were significantly decreased in a unilateral compression of multiple DRG model （ ipsilateral ： 4.0 ± 0.4 g, P 〈 10^-2 ; contralateral ： 6.0± 0.5 g, P 〈 10^-6, n = 29 ）. Furthermore, both ipsilateral and contralateral response scores to acetone were obviously increased after the chronic compression of multiple DRGs （ ipsilateral： 2.1 ±0.1, P 〈0.01; contralateral： 1.6 ±0.2, P 〈0.01, n = 16）. Histological study showed obvious inflammation occurred in injured ipsilateral DRGs and their nerve root nearby. Conclusion： Both mechanical deformation and inflammatory irritation of nerve roots and DRGs are involved in the behaviors of mechanical and cold allodynia, accompanying with obvious delayed mirror pains in chronically compressed multiple DRG rats.