The active ion transport properties of canine lingual epithelia in vitro. Implications for gustatory transduction.
The active ion transport properties of canine lingual epithelia in vitro. Implications for gustatory transduction.
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体外犬舌上皮的活性离子传输特性。对味觉传导的影响。
DOI：
10.1085/jgp.83.5.633
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发表时间：
1984-05
影响因子：
3.8
通讯作者：
Desimone, S K
中科院分区：
文献类型：
--
作者：
Desimone, J A;Heck, G L;Mierson, S;Desimone, S K
研究了离体犬舌背侧和腹侧上皮细胞的电生理特性。背侧上皮含有一种特殊的离子转运系统，可被NaCl或LiCl中的高渗粘膜溶液激活。高渗KCl作为该系统的激活剂的有效性显著降低。舌系带不包含运输系统。在背侧表面，它的特点是在内向电流的快速增加，并可以定量为第二个组件的时间过程中的开路电位或短路电流时，粘膜溶液是高渗的NaCl或LiCl。增加的内向电流（高渗反应）可被阿米洛利（10（-4）M）消除。这个运输系统在背表面的具体位置和事实上，它在哺乳动物的盐味特征的浓度范围内运作，这表明味觉转导的可能联系。这种可能性是通过记录神经反应在大鼠的NaCl和KCl的浓度范围内，包括高渗。我们表明，阿米洛利专门阻断高渗范围内的NaCl的反应，而影响KCl的反应显着less. Results结果表明，味觉转导NaCl介导的Na进入味觉细胞通过相同的阿米洛利敏感的途径，负责在体外的高渗反应。体外系统的进一步研究提供了旁细胞以及跨细胞电流路径的证据。在对称和不对称条件下，跨壁电流-电压关系均为线性。在对称条件下哇巴因处理后，短路电流衰减至零。电阻的增加虽然显著，但很小，这表明电流的分流路径相当大。通量测量表明，钠在对称条件下被吸收。在各种糖中高渗的粘液素溶液也诱导阿米洛利敏感的内向电流。总之，这项工作提供的证据表明，钠味觉受体最有可能是一个钠转运系统，特别是适应舌背表面。味觉的运输范式也提出了一个简单的电味觉模型和甜味的可能机制。
The electrophysiological properties of the dorsal and ventral canine lingual epithelium are studied in vitro. The dorsal epithelium contains a special ion transport system activated by mucosal solutions hyperosmotic in NaCl or LiCl. Hyperosmotic KCl is significantly less effective as an activator of this system. The lingual frenulum does not contain the transport system. In the dorsal surface it is characterized by a rapid increase in inward current and can be quantitated as a second component in the time course of either the open-circuit potential or short-circuit current when the mucosal solution is hyperosmotic in NaCl or LiCl. The increased inward current (hyperosmotic response) can be eliminated by amiloride (10(-4) M). The specific location of this transport system in the dorsal surface and the fact that it operates over the concentration range characteristic of mammalian salt taste suggests a possible link to gustatory transduction. This possibility is tested by recording neural responses in the rat to NaCl and KCl over a concentration range including the hyperosmotic. We demonstrate that amiloride specifically blocks the response to NaCl over the hyperosmotic range while affecting the KCl response significantly less. The results suggest that gustatory transduction for NaCl is mediated by Na entry into the taste cells via the same amiloride-sensitive pathway responsible for the hyperosmotic response in vitro. Further studies of the in vitro system give evidence for paracellular as well as transcellular current paths. The transmural current-voltage relations are linear under both symmetrical and asymmetrical conditions. After ouabain treatment under symmetrical conditions, the short-circuit current decays to zero. The increase in resistance, though significant, is small, which suggests a sizeable shunt pathway for current. Flux measurements show that sodium is absorbed under symmetrical conditions. Mucosal solutions hyperosmotic in various sugars also induce an amiloride-sensitive inward current. In summary, this work provides evidence that the sodium taste receptor is most probably a sodium transport system, specifically adapted to the dorsal surface of the tongue. The transport paradigm of gustation also suggests a simple model for electric taste and possible mechanisms for sweet taste.