Behavioral characteristics and c-Fos expression in the medullary dorsal horn in a rat model for orofacial cancer pain
Behavioral characteristics and c-Fos expression in the medullary dorsal horn in a rat model for orofacial cancer pain
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DOI：
10.1016/j.ejpain.2008.05.004
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发表时间：
2009-04-01
影响因子：
3.6
通讯作者：
Nakanishi, Osamu
中科院分区：
文献类型：
--
作者：
Ono, Kentaro;Harano, Nozomu;Nakanishi, Osamu
众所周知，口面癌患者患有癌症引起的疼痛，从而产生进食困难。为了了解口面癌疼痛的机制，我们最近建立了大鼠口面癌模型，通过将步行者癌肉瘤256 B细胞接种到触须垫中。本研究采用行为学和免疫组织化学技术来研究疼痛相关行为和摄食行为的变化，沿着c-Fos在延髓背角的表达，延髓背角是处理口面疼痛的部位。瘤块逐渐生长，并在接种肿瘤细胞后数天内接触神经干。接种后第10天观察到摄食身体困难，面部梳理期延长。在第4天和第7天，接种的触须垫对机械和热刺激的敏感性增加，表明机械异常性疼痛和热痛觉过敏的发展。虽然在接种区域中观察到对机械和热刺激的低敏感性在第10天之后，但在肿瘤的边缘上产生痛觉过敏，这表明过敏区域随着肿瘤块的生长而扩散。在脊髓背角，同侧的c-Fos免疫反应性的水平显着增加，在第4，7和10天，支持的行为观察。这些结果表明，大鼠模型显示出与口面癌患者相似的症状，例如，诱发进食障碍和神经性疼痛。(c)2008年，国际疼痛研究协会欧洲分会联合会。由爱思唯尔有限公司出版。保留所有权利。
It is well known that patients with orofacial cancer suffer from cancer-induced pain which produces feeding difficulties. To understand the mechanisms of pain associated with orofacial cancer, we have recently created a model for rat orofacial cancer by inoculation with Walker carcinosarcoma 256B-cells into the vibrissal pads. The present study used both behavioral and immunohistochemical techniques to investigate changes in pain-related and ingestive behavior, along with c-Fos expression in the medullary dorsal horn which is a site for processing orofacial pain. The tumor mass grew gradually and contacted the nerve trunks within days after the inoculation of tumor cells. Physical difficulties in ingestion were observed after day 10 post-inoculation and facial grooming periods were prolonged. Sensitivities of the inoculated vibrissal pads to mechanical and thermal stimuli were increased on days 4 and 7, suggesting the development of mechanical allodynia and thermal hyperalgesia. Although hyposensitivity to mechanical and thermal stimulation was observed in the inoculated region after day 10, hyperalgesia developed on the margin of the tumor, suggesting that the hypersensitive region spread with growth of tumor mass. In the medullary dorsal horn, the levels of c-Fos immunoreactivity of the ipsilateral side increased significantly on days 4, 7 and 10, supporting the behavioral observations. These results indicate that the rat model shows symptoms similar to those in patients with orofacial cancer, for example, induction of feeding disorder and neuropathic pain. (c) 2008 European Federation of Chapters of the International Association for the Study of Pain. Published by Elsevier Ltd. All rights reserved.