The odontoblast as a sensory receptor cell? The expression of TRPV1 (VR-1) channels
The odontoblast as a sensory receptor cell? The expression of TRPV1 (VR-1) channels
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DOI：
10.1679/aohc.68.251
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发表时间：
2005-12-01
影响因子：
--
通讯作者：
Shibukawa, Y
中科院分区：
文献类型：
--
作者：
Okumura, R;Shima, K;Shibukawa, Y
先前的报告显示，成牙本质细胞质膜上有几种机械敏感离子通道的表达，成牙本质细胞是负责牙本质形成的细胞。成牙本质细胞的膜特征意味着它们可以在牙本质小管内的液体置换到电细胞信号的机械转导中发挥关键作用，从而将牙本质感觉传递到中枢神经系统。然而，这种牙本质伤害感受功能背后的直接离子机制仍不清楚。在本研究中，我们通过免疫组织化学和制霉菌素穿孔膜片钳技术研究了大鼠成牙本质细胞中瞬时受体电位香草酸亚家族成员 1 (TRPV1) 通道的表达，该通道本质上有助于检测痛觉。免疫组织化学观察显示 TRPV1 免疫反应定位于成牙本质细胞膜的远端区域。在膜片钳实验中，我们观察到辣椒素诱导的内向电流被 TRPV1 通道拮抗剂辣椒西平抑制。我们的结果表明TRPV1通道在成牙本质细胞中显着表达，表明成牙本质细胞可能直接对有害刺激（例如热-热刺激）做出反应，并指出有必要重新考虑基于成牙本质细胞跨膜离子信号的牙本质感觉的细胞机制。
Previous reports have shown the expression of several mechanosensitive ionic channels on the plasma membrane in odontoblasts, which are the cells responsible for dentin formation. The membrane characteristics of odontoblasts imply that they could play critical roles in the mechano-transduction of fluid displacement within dentinal tubules into the electrical cell signals, to carry dentin sensation to the central nervous system. However, the direct ionic mechanism underlying such a dentin nociceptive function remains unclear. In the present study, we investigated the expression of the transient receptor potential vanilloid subfamily member 1 (TRPV1) channel-which essentially contributes to the detection of pain sensation-in rat odontoblasts by immunohistochemical and nystatin perforated patch-clamp techniques. Immunohistochemical observation showed the localization of TRPV1-immunoreactions on the distal regions of odontoblast membranes. In the patch-clamp experiments, we observed capsaicin-induced inward currents that were inhibited by capsazepine, a TRPV1 channel antagonist. Our results indicate a significant expression of TRPV1 channels in odontoblasts, suggesting that odontoblasts may directly respond to noxious stimuli such as a thermal-heat stimulus, and point to the necessity for a reconsideration of the cellular mechanisms of dentin sensation based on the transmembrane ionic signals in odontoblasts.