Murata Yasuaki, Onda Akira, Rydevik Björn, Takahashi Ichiro, Takahashi Kazuhisa, Olmarker Kjell
Department of Orthopaedic Surgery, School of Medicine, Chiba University, Chiba, Japan.
Spine (Phila Pa 1976). 2006 Mar 1;31(5):530-5. doi: 10.1097/01.brs.0000201260.10082.23.
Histologic changes in the dorsal root ganglion (DRG) and the nociceptive stimulation thresholds were studied in rats.
To examine the effects of tumor necrosis factor-alpha (TNF) with special reference to pain behavior and histology of the DRG.
Recently, it was reported that local application of nucleus pulposus induces a characteristic tissue reaction at the surface of the DRG. However, to our knowledge, there have been no previous reports about the relationship between the histologic changes and pain behavior caused by cytokines.
Recombinant TNF was applied to the L4 DRG. Mechanical and thermal nociceptive thresholds were tested. The L4 DRG was sectioned and observed by light microscopy.
After the application of 5 ng/microL TNF, significant differences were observed in mechanical and thermal stimulation thresholds. At the site of application of TNF, a characteristic a semilunar-shaped enlargement was observed. The average width of the part was significantly larger in the 5 ng/microL TNF application, as compared to the 0.5-ng/microL TNF application.
The higher concentration of TNF used induced allodynia and hyperalgesia responses. Because the region showing the histologic changes was significantly larger after application of the higher concentration of TNF, the reaction of the DRG may be related to pain.
对大鼠背根神经节（DRG）的组织学变化及伤害性刺激阈值进行了研究。
特别参照疼痛行为和DRG的组织学，研究肿瘤坏死因子-α（TNF）的作用。
最近有报道称，局部应用髓核可在DRG表面诱导出特征性组织反应。然而，据我们所知，此前尚无关于细胞因子引起的组织学变化与疼痛行为之间关系的报道。
将重组TNF应用于L4 DRG。测试机械性和热伤害性阈值。对L4 DRG进行切片并通过光学显微镜观察。
应用5 ng/μL TNF后，在机械性和热刺激阈值方面观察到显著差异。在TNF应用部位，观察到特征性的半月形增大。与应用0.5 ng/μL TNF相比，应用5 ng/μL TNF时该部位的平均宽度显著更大。
使用的较高浓度TNF诱导了痛觉过敏和痛觉超敏反应。由于应用较高浓度TNF后显示组织学变化的区域明显更大，DRG的反应可能与疼痛有关。
