PROTON CURRENTS THROUGH AMILORIDE-SENSITIVE NA+ CHANNELS IN ISOLATED HAMSTER TASTE CELLS - ENHANCEMENT BY VASOPRESSIN AND CAMP
PROTON CURRENTS THROUGH AMILORIDE-SENSITIVE NA+ CHANNELS IN ISOLATED HAMSTER TASTE CELLS - ENHANCEMENT BY VASOPRESSIN AND CAMP
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DOI：
10.1016/0896-6273(93)90208-9
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发表时间：
1993-05-01
期刊：
影响因子：
16.2
通讯作者：
KINNAMON, SC
中科院分区：
文献类型：
--
作者：
GILBERTSON, TA;ROPER, SD;KINNAMON, SC
Amiloride has been suggested to inhibit responses to a variety of taste stimuli, including salty, sweet, and sour (acid). To test for the involvement of amiloride-sensitive Na+ channels in the transduction of acid stimuli, fungiform taste receptor cells were examined using patch-clamp techniques. Approximately one-half of all cells had amiloride-sensitive Na+ currents (I(Na)) with a K(i) value near 0.2 muM amiloride. After blocking voltage-gated conductances, cells having amiloride sensitivity were tested for responses to acid stimuli. Over three-fourths of cells showed an inward proton current (I(H+)) with an extrapolated reversal potential near approximately +150 mV, which was completely blocked by amiloride (30 muM). Treatment of isolated taste cells with arginine8-vasopressin caused equivalent increases in both I(Na) and I(H+); each effect was mimicked by 8-Br-cAMP. Taken together, these results indicate that protons permeate amiloride-sensitive Na+ channels in hamster fungiform taste cells and contribute to acid transduction.
