Benham Christopher D, Gunthorpe Martin J, Davis John B
Neurology, GlaxoSmithKline Research and Development Ltd., New Frontiers Science Park (North), Third Avenue, Harlow, Essex CM19 5AW, UK.
Cell Calcium. 2003 May-Jun;33(5-6):479-87. doi: 10.1016/s0143-4160(03)00063-0.
The past year has seen a doubling in the number of heat-sensitive ion channels to six, and four of these channels are from the TRPV family. These channels characteristically have Q(10) values of >10 above the thermal threshold, very different from the Q(10) values of 1.5-2.0 seen in most ion channels. Cells expressing TRPV1 show similar temperature sensitivity to small capsaicin-sensitive nociceptor neurons, consistent with these neurons expressing homomers of TRPV1. A-delta fibres exhibit properties that may be explained by TRPV2 containing channels which is present in large diameter sensory neurons that do not express TRPV1. TRPV3 has a lower temperature threshold and may contribute to warm-sensitive channels together with TRPV1. Warm sensation may also be transduced by TRPV4 expressing sensory neurons and hypothalamic neurons. We can now look forward to further work defining the properties of the recombinant channels in more detail and a re-analysis of endogenous i(heat) currents in thermosensitive neurons and other cells. Data from the study of mice in which TRPV2, TRPV3 or TRPV4 have been deleted are also eagerly awaited.
在过去一年中，热敏离子通道的数量增加了一倍，达到六个，其中四个通道来自TRPV家族。这些通道的特征是在热阈值以上的Q(10)值大于10，这与大多数离子通道中所见的1.5 - 2.0的Q(10)值非常不同。表达TRPV1的细胞对小辣椒素敏感的伤害性感受神经元表现出相似的温度敏感性，这与这些神经元表达TRPV1同聚体一致。A - δ纤维表现出的特性可能由存在于不表达TRPV1的大直径感觉神经元中的含TRPV2通道来解释。TRPV3具有较低的温度阈值，可能与TRPV1一起构成温敏通道。热感觉也可能由表达TRPV4的感觉神经元和下丘脑神经元传导。我们现在期待进一步的工作，更详细地定义重组通道的特性，并重新分析热敏神经元和其他细胞中的内源性i(热)电流。同时也急切期待来自TRPV2、TRPV3或TRPV4基因敲除小鼠研究的数据。
