Effects of eugenol on Na+ currents in rat dorsal root ganglion neurons
Effects of eugenol on Na+ currents in rat dorsal root ganglion neurons
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DOI：
10.1016/j.brainres.2008.09.030
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发表时间：
2008-12-03
期刊：
影响因子：
2.9
通讯作者：
Song, Jin-Ho
中科院分区：
文献类型：
--
作者：
Cho, Jeong Seon;Kim, Tae Hoon;Song, Jin-Ho
丁香酚是一种芳香分子，存在于几种植物中，广泛用于牙科镇痛和防腐。它抑制促炎介质，包括一氧化氮合酶，环氧合酶和脂氧合酶。它还调节参与疼痛信号传导的离子通道，如TRPV 1受体、高电压激活的Ca 2+通道、NMDA受体和GABA（A）受体。在炎症或神经损伤后，初级感觉神经元中电压门控Na+通道的表达和功能特性发生改变。为了阐明Na+通道参与丁香酚镇痛作用，我们研究了丁香酚对急性分离的大鼠背根神经节神经元河豚毒素敏感（TTX-S）和河豚毒素抵抗（TTX-R）Na+电流的影响。丁香酚以浓度依赖性方式抑制TTX-S和TTX-R Na+电流。K-d值分别为308 μ M和543 μ M。丁香酚不影响任何类型的Na+电流的激活电压。然而，丁香酚移动的稳态失活曲线的两个Na+电流的超极化方向，并减少最大Na+电流。因此，丁香酚似乎通过其与静息和失活Na+通道的相互作用来抑制Na+电流。从失活的两个Na+电流的恢复被丁香酚减慢。丁香酚对Na+电流的抑制作用不依赖于刺激频率。抑制Na+电流被认为是丁香酚发挥镇痛作用的机制之一。(C)2008 Elsevier B. V.保留所有权利。
Eugenol is an aromatic molecule found in several plants and widely used in dentistry for analgesic and antiseptic purposes. It inhibits pro-inflammatory mediators including nitric oxide synthase, cyclooxygenase and lipoxygenase. It also regulates ion channels involved in pain signaling, such as TRPV1 receptor, high-voltage-activated Ca2+ channels, NMDA receptor and GABA(A) receptor. The expression and functional properties of voltage-gated Na+ channels in primary sensory neurons are altered following inflammation or nerve injury. To elucidate an involvement of Na+ channels in-the eugenol-induced analgesia we investigated the effects of eugenol on tetrodotoxin-sensitive (TTX-S) and tetrodotoxin-resistant (TTX-R) Na+ currents in acutely dissociated rat dorsal root ganglion neurons. Eugenol inhibited TTX-S and TTX-R Na+ currents in a concentration-dependent manner. The K-d values were 308 PM and 543 mu M, respectively. Eugenol did not influence the activation voltage of either type of Na+ current. However, eugenol moved the steady-state inactivation curves of both Na+ currents to a hyperpolarizing direction and reduced the maximal Na+ current. Thus eugenol appears to inhibit Na+ currents through its interaction with both resting and inactivated Na+ channels. The recovery from inactivation of both Na+ currents was slowed by eugenol. The eugenol inhibition of Na+ currents was not dependent on the stimulus frequency. The inhibition of Na+ currents is considered as one of the mechanisms by which eugenol exerts analgesia. (C) 2008 Elsevier B.V. All rights reserved.