Jaw electromyographic activity induced by the application of algesic chemicals to the rat tooth pulp
Jaw electromyographic activity induced by the application of algesic chemicals to the rat tooth pulp
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DOI：
10.1016/s0304-3959(98)00241-3
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发表时间：
1999-04-01
期刊：
影响因子：
7.4
通讯作者：
Hu, JW
中科院分区：
文献类型：
--
作者：
Sunakawa, M;Chiang, CY;Hu, JW
本研究的目的是确定芥子油（MO），一种小纤维兴奋剂和炎症刺激剂，或其他痛觉化学物质（辣椒素，CAP和缓激肽，BK）的应用程序到大鼠上颌磨牙牙髓诱导咬肌和二腹肌的肌电图（EMG）活动，并确定是否内源性阿片类药物的机制可能参与任何记录的EMG变化。应用MO的牙髓诱导的同侧咬肌的EMG活动的显着增加长达30分钟。应用矿物油的纸浆或MO应用到牙髓拔除的牙齿没有引起任何显着的EMG增加。CAP或BK应用于牙髓相比，对颌肌肌电图活动的影响要弱得多。CAP产生了一个小的，但长期增加咬肌肌电活动，和BK诱导的二腹肌肌电活动的短暂持续增加。阿片拮抗剂纳洛酮的全身给药显著地重新激活（即重新点燃）由MO应用于牙髓诱发的EMG反应。在CAP、BK或矿物油应用于牙髓或MO应用于牙髓拔除的牙齿后，纳洛酮对EMG活动没有产生任何显著的再点燃效应。MO，BK，特别是CAP组显示血管扩张和多形核白细胞浸润的牙髓组织和埃文斯蓝染料的血浆外渗显着增加的组织学证据，而矿物油没有引起这些变化。这些结果表明，由BK，CAP，特别是MO诱发的到中枢神经系统的牙髓传入输入可以引起增强的颌肌活动。此外，纳洛酮的数据表明，阿片抑制机制可能是由牙髓传入输入诱发的MO，并可能有助于限制这些输入引起的颌肌活动。(C)1999年国际疼痛研究协会。出版社：Elsevier Science B.V.
The aim of this study was to determine if the application of mustard oil (MO), a small-fiber excitant and inflammatory irritant, or other algesic chemicals (capsaicin, CAP, and bradykinin, BK) to the rat maxillary molar tooth pulp induces electromyographic (EMG) activity of the masseter and digastric muscles, and also to determine if endogenous opioid mechanisms may be involved in any documented EMG changes. Application of MO to the tooth pulp induced a significant increase in EMG activity of the ipsilateral masseter up to 30 min. The application of mineral oil to the pulp or MO application to the pulp-extirpated tooth did not induce any significant EMG increases. The application of CAP or BK to the pulp in contrast had much weaker effects on EMG activity of the jaw muscles. CAP produced a small but prolonged increase in masseter EMG activity, and BK induced a short-lasting increase in digastric EMG activity. The systemic administration of the opiate antagonist naloxone significantly reactivated (i.e. rekindled) the EMG response evoked by MO application to the pulp. Naloxone did not produce any such significant rekindling effect on EMG activity following CAP, BK or mineral oil application to the pulp or following MO application to the pulp-extirpated tooth. The MO, BK and especially CAP groups showed histological evidence of vasodilatation and polymorphonuclear leukocyte infiltration in the pulp tissue and a significant increase in plasma extravasation of Evans Blue dye, whereas mineral oil did not induce these changes. These findings suggest that pulp afferent inputs to the central nervous system evoked by BK, CAP and especially MO may induce enhanced jaw muscle activity. In addition, the naloxone data suggest that an opioid suppressive mechanism may be induced by the pulpal afferent inputs evoked by MO, and may serve to limit the jaw muscle activity elicited by these inputs. (C) 1999 International Association for the Study of Pain. Published by Elsevier Science B.V.