权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Study on the peripheral mechanism of hyperalgesia to mechanical and cold stimulations

机械刺激和冷刺激痛觉过敏的外周机制研究

基本信息

批准号：
11470016
负责人：
MIZUMURA Kazue
金额：
$ 9.28万
依托单位：
NAGOYA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2001
项目状态：
已结题

项目摘要

The purpose of this study is to clarify the peripheral mechanisms of mechanical and cold hyperalgesia. We found :1 ) Inflammatory mediators such as bradykinin, histamine and prostaglandin E2 as well as substances that were supposed to be second messengers of these mediators, sensitized the mechanical response of canine testicular polymodal receptors in vitro.2 ) Bradykinin response of Of C-fiber nociceptors recorded in rats with adjuvant-induced polyarthritis showed more than 1000 times higher sensitivity to bradykinin. Based on the assumption that this increased sensitivity might be resulted from the increased expression of B2 bradykinin receptor in sensory neurons, we measured B2 receptor mRNA in dorsal root ganglia (DRG_s) with RT-PCR method. We found 2.5 times increase in B2 receptor in DRG_s 1 week after inoculation of adjuvant.3 ) Animals with adjuvant-induced monoarthritis showed hyperalgesia to mechanical stimulation with von Frey hairs and to mild cold stimulation with aceton drops 10-14 days after injection.4 ) Corresponding to the existence of cold hyperalgesia in monoarthritic rat the percentage of C-fiber nociceptors responding to cold stimulation up to 2℃ increased, and C-low threshold mechanoreceptors showed augmented responses to mild cold stimulation. These results suggest that increased cold sensitivity of not only nociceptors but also low threshold mechanoreceptors, which are commonly believed not to involved in nociception, play some role in hyperalgesia to cold.

本研究的目的是阐明机械和冷痛觉过敏的外周机制。我们发现：1) 炎症介质，如缓激肽、组胺和前列腺素 E2 以及被认为是这些介质第二信使的物质，在体外使犬睾丸多模式受体的机械反应敏感。2) 在患有佐剂诱导的多关节炎的大鼠中记录的 C 纤维伤害性感受器的缓激肽反应显示出比佐剂诱导的多关节炎大鼠高 1000 倍的敏感性。缓激肽。基于这种敏感性增加可能是由于感觉神经元中 B2 缓激肽受体表达增加所致，我们采用 RT-PCR 方法测量了背根神经节 (DRG_s) 中 B2 受体 mRNA。我们发现，接种佐剂后 1 周，DRG_s 中的 B2 受体增加了 2.5 倍。3) 佐剂诱导的单关节炎动物在注射后 10-14 天，对 von Frey 毛的机械刺激和丙酮滴的轻度冷刺激表现出痛觉过敏。4) 与单关节炎大鼠中冷痛觉过敏的存在相对应，C 纤维伤害性感受器对冷刺激做出反应的百分比升高达2℃，C-低阈值机械感受器对轻度冷刺激的反应增强。这些结果表明，不仅伤害感受器的冷敏感性增加，而且通常认为不参与伤害感受的低阈值机械感受器的冷敏感性增加，也在对冷的痛觉过敏中发挥了一定作用。