Different symptoms of neuropathic pain can be induced by different degrees of compressive force on the C7 dorsal root of rats
Different symptoms of neuropathic pain can be induced by different degrees of compressive force on the C7 dorsal root of rats
复制标题
对大鼠C7背根施加不同程度的压迫力可诱发不同的神经病理性疼痛症状
DOI：
10.1016/j.spinee.2012.10.036
复制
发表时间：
2012-12-01
期刊：
影响因子：
4.5
通讯作者：
Guo, Qulian
中科院分区：
文献类型：
--
作者：
Huang, Changsheng;Zou, Wangyuan;Guo, Qulian
背景背景：神经损伤后的神经性疼痛以阳性和阴性感觉症状和体征为特征。神经损伤后感觉纤维损失的程度已被证明与神经性疼痛的症状相关，通过定量感觉测试和小神经纤维活检证实。然而，大神经损伤的病理改变与疼痛症状之间的关系尚不清楚。目的：探讨背根损伤程度与神经性疼痛症状的关系。研究设计：神经损伤及以下疼痛相关行为和神经病理改变的评估。方法：取体重250 ~ 300 g的成年雄性Sprague-Dawley大鼠24只，随机分为3组（每组8只）：假手术组、不压迫神经组、70 gf组、180 gf组；分别对右侧C7背根施加70或180 g的压缩力。在术前（基线）和术后第1、3、5、7天测量阈值热痛和机械性痛。术后第7天处死大鼠，观察受压区神经纤维结构变化。结果：70 g的压缩力导致痛觉过敏，而180 g的压缩力在损伤后7天内引起同侧前爪对机械和热刺激的痛觉减退。光镜和电镜显示，70-gf压缩后感觉纤维有轻度至中度损失，180-gf压缩后感觉纤维损失更严重。结论：短暂性感觉纤维损伤可产生神经性疼痛的阳性或阴性症状，不同程度损伤后感觉纤维损失程度的不同可能是导致神经性疼痛症状不同的原因。(c) 2012 Elsevier Inc.版权所有。
BACKGROUND CONTEXT: Neuropathic pain after nerve injuries is characterized by positive and negative sensory symptoms and signs. The extent of sensory fiber loss after nerve injuries has been demonstrated to correlate with symptoms of neuropathic pain by quantitative sensory testing and confirmed by biopsies of small nerve fibers. However, the relationship between the pathologic changes of large nerves on injuries and resulting pain symptoms remains unclear.PURPOSE: To investigate the relationship between the extent of dorsal root injury and resulting symptoms of neuropathic pain.STUDY DESIGN: Nerve injury and assessment of the following pain-related behaviors and neuropathologic changes.METHODS: A total of 24 adult male Sprague-Dawley rats weighing 250 to 300 g were randomly divided into three groups (n=8 each): sham group operated on but without nerve compression, 70 gf group, and 180 gf group; a compression force of 70 or 180 g was applied to the right C7 dorsal root, separately. Threshold thermal and mechanical pains were measured before surgery (baseline) and on the first, third, fifth, and seventh day after surgery. On the seventh day after surgery, all rats were killed, and the structural alterations of nerve fibers within the compressed areas were examined.RESULTS: A compression force of 70 g resulted in hyperalgesia, whereas a compression force of 180 g induced hypoalgesia in the ipsilateral forepaw in response to both mechanical and thermal stimulations within 7 days after injury. Light microscopy and electron microscopy revealed a mild to moderate sensory fiber loss after 70-gf compression and a more severe sensory fiber loss after 180-gf compression.CONCLUSIONS: Transient injuries on sensory fibers can produce either positive or negative symptoms of neuropathic pain, and the different extent of sensory fiber loss after different degrees of injuries might account for the varied resulting symptoms of neuropathic pain. (c) 2012 Elsevier Inc. All rights reserved.