Extracellular signal-regulated kinase mitogen-activated protein kinase activation in the dorsal root ganglion (DRG) and spinal cord after DRG injury in rats
Extracellular signal-regulated kinase mitogen-activated protein kinase activation in the dorsal root ganglion (DRG) and spinal cord after DRG injury in rats
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DOI：
10.1097/01.brs.0000182091.53834.08
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发表时间：
2005-10-15
期刊：
影响因子：
3
通讯作者：
Yamashita, T
中科院分区：
文献类型：
--
作者：
Doya, H;Ohtori, S;Yamashita, T
研究设计.我们通过电化学检测磷酸化ERK（pERK）来研究背根神经节（DRG）和脊髓中细胞外信号调节激酶（ERK）的激活。阐明背根节损伤后大鼠神经系统中ERK的激活。已知神经根性疼痛与椎间盘突出引起的DRG损伤有关。ERK在伤害性刺激下通过DRG和脊髓中的磷酸化而被激活，这与疼痛超敏性有关。在左侧L4 DRG挤压伤后2 min至24 h，切除L4 DRG和脊髓，制备连续切片，行组织化学观察。在DRG中，在2分钟时在神经元和卫星细胞中检测到ERK激活;前者维持在增加的水平20分钟，后者维持4小时。在30分钟时，在许旺细胞中观察到pERK免疫反应性，其持续长达24小时。在脊髓中，pERK阳性神经元在2 min时检测到，并且pERK水平在升高的水平上维持20 min。DRG损伤后神经元中pERK诱导的分布在DRG和脊髓之间相似，而卫星细胞中的pERK诱导更持久。背根神经节雪旺氏细胞pERK的诱导是迟发性的，并且持续时间最长。
Study Design. We investigated the extracellular signal-regulated kinase (ERK) activation by immunohistochemically detecting phosphorylated ERK (pERK) in the dorsal root ganglion (DRG) and spinal cord.Objective. To clarify the ERK activation in the rat nervous system following DRG injury.Summary of Background Data. Radicular pain is known to be associated with DRG injury caused by intervertebral disc herniation. ERK is activated by phosphorylation in the DRG and spinal cord by noxious stimuli, which are related to pain hypersensitivity.Methods. From 2 minutes to 24 hours after the left L4 DRG crush injury, L4 DRGs and spinal cords were resected to prepare serial sections, which were investigated immunohistochemically.Results. In the DRG, ERK activation was detected in neurons and satellite cells at 2 minutes; the former was maintained at increased levels for 20 minutes, and the latter for 4 hours. At 30 minutes, pERK immunoreactivity was observed in Schwann cells, which continued for up to 24 hours. In the spinal cord, pERK-positive neurons were detected at 2 minutes, and the pERK levels were maintained at increased levels for 20 minutes.Conclusions. Profiles of pERK induction in neurons after DRG injury were similar between the DRG and spinal cord, whereas pERK induction in the satellite cells was more long lasting. The pERK induction in Schwann cells in the DRG was late onset and the most long lasting.