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INTERACTION BETWEEN PAIN AND VASODILATION INTHE PULPITIS, IDENTIFICATION OF VASODILATOR SUBSTANCES

牙髓炎疼痛与血管舒张之间的相互作用，血管舒张物质的鉴定

基本信息

批准号：
12671847
负责人：
SASANO Takashi
金额：
$ 2.05万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

项目摘要

(1) Histamine is a classical, but still interesting inflammatory mediator. Many people have long believed that histamine is derived from mast cells or basophils alone. However, the hidtamine forming enzyme, histidine decarboxylase (HDC), is induced in a variety of tissues in responses to gram-positive and gram-negative bacterial components and to various cytokines. HDC is induced even in mast-cell-deficient mice. The histamine newly formed via the induction of HDC is released immediately and may be involved in a variety of immune responses. We conclude that histamine can be produced via the induction of HDC by a mechanism coupled with cytokine network. We call this histamine neohistamine to distinguish it from the classical histamine derived from mast cells or basophils. Neohistamine is involved in physiological reactions, inflammation, immune responses and a variety of diseases such as pulpitis.(2) Dynamic changes in pulpal blood flow (PBF) in cat mandibular canine teeth were elicited by electrical stimulation of the distal cut end of IAN, at various levels of baseline blood flow (BBF), with blood flow monitored by Laser Doppler Flowmetry. The amplitude of the PBF vasodilator response increased as BBF was adjusted downwards (by cooling down the tooth). In contrast, the amplitude of the PBF vasoconstrictor response increased as the BBF level rose. Vasodilator responses could be transformed into vasoconstrictor responses, and vice versa, by alterations in the BBF level. No systemic blood pressure changes were elicited throughout the experiment. These results indicate that a consideration of baseline vascular tone is important whenever we discuss or calculate the size of PBF responses to various stimuli.

(1)组胺是一个经典的，但仍然有趣的炎症介质。长期以来，许多人认为组胺仅来源于肥大细胞或嗜碱性粒细胞。然而，组胺形成酶，组氨酸脱羧酶（HDC），在各种组织中诱导革兰氏阳性和革兰氏阴性细菌组分和各种细胞因子。即使在肥大细胞缺陷小鼠中也能诱导HDC。通过诱导HDC新形成的组胺立即释放，并可能参与多种免疫反应。我们的结论是，组胺可以产生通过诱导HDC的机制耦合细胞因子网络。我们称之为组胺新组胺，以区别于来自肥大细胞或嗜碱性粒细胞的经典组胺。新组胺参与生理反应、炎症、免疫反应和多种疾病如牙髓炎。(2)用激光多普勒血流仪监测猫下颌犬牙的牙髓血流量，观察电刺激牙槽嵴远侧切端引起的牙髓血流量的动态变化。随着BBF向下调整（通过冷却牙齿），PBF血管舒张反应的幅度增加。相反，PBF缩血管反应的幅度随着BBF水平的升高而增加。血管舒张反应可以转化为血管收缩反应，反之亦然，通过改变BBF水平。在整个实验过程中没有引起全身血压变化。这些结果表明，基线血管张力的考虑是很重要的，当我们讨论或计算PBF的大小对各种刺激的反应。