AMILORIDE-BLOCKABLE SODIUM CURRENTS IN ISOLATED TASTE RECEPTOR-CELLS
AMILORIDE-BLOCKABLE SODIUM CURRENTS IN ISOLATED TASTE RECEPTOR-CELLS
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DOI：
10.1007/bf01871001
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发表时间：
1988-11-01
影响因子：
2.4
通讯作者：
LINDEMANN, B
中科院分区：
文献类型：
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作者：
AVENET, P;LINDEMANN, B
在全细胞膜片钳技术条件下，研究了蛙舌味觉感受器细胞的分离。当胞浆电位保持在-80 mV时，超过50%的细胞在林格氏液中具有10 - 700 pA的稳态内向钠电流。这种电流在一些细胞中部分存在，在另一些细胞中完全存在，可被低浓度的阿米洛利阻断。在外溶液中加入110 mM Na，在内溶液中加入10 mM Na，阿米洛利的抑制常数（在-80 mV）接近0.3 μ M。在某些细胞中，阿米洛利敏感的电导是钠特异性的;在其他细胞中，它通过钠和钾。Na/K选择性（从反转电位估计）在1和100之间变化。小浓度的阿米洛利的阻断类似于在一些钠吸收上皮细胞中发现的通道，但味觉细胞的通道显示出令人惊讶的大范围的离子特异性。受体细胞，在原位表达这些通道在其顶端膜，可能有能力检测的味道质量“咸”。相同的细胞也表达TTX可阻断的电压门控Na通道。
Isolated taste receptor cells from the frog tongue were investigated under whole-cell patch-clamp conditions. With the cytosolic potential held at -80 mV, more than 50% of the cells had a stationary inward Na current of 10 to 700 pA in ringer''s solution. This current was in some cells partially, in others completely, blockable by low concentrations of amiloride. With 110 mM Na in the external and 10 mM Na in the internal solution, the inhibition constant of amiloride was (at -80 mV) near 0.3 .mu.M. In some cells the amiloride-sensitive conductance was Na specific; in others it passed both Na and K. The Na/K selectivity (estimated from reversal potentials) varied between 1 and 100. The blockability by small concentrations of amiloride resembled that of channels found in some Na-absorbing epithelia, but the channels of taste cells showed a suprisingly large range of ionic specificities. Receptor cells, which in situ express these channels in their apical membrane, may be competent to detect the taste quality "salty". The same cells also express TTX-blockable voltage-gated Na channels.