PROTON CURRENTS THROUGH AMILORIDE-SENSITIVE NA+ CHANNELS IN ISOLATED HAMSTER TASTE CELLS - ENHANCEMENT BY VASOPRESSIN AND CAMP

被引:131
作者
GILBERTSON, TA
ROPER, SD
KINNAMON, SC
机构
[1] UNIV COLORADO, HLTH SCI CTR, ROCKY MT TASTE & SMELL CTR, DENVER, CO 80262 USA
[2] COLORADO STATE UNIV, DEPT ANAT & NEUROBIOL, FT COLLINS, CO 80523 USA
关键词
D O I
10.1016/0896-6273(93)90208-9
中图分类号
Q189 [神经科学];
学科分类号
071006 ;
摘要
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.
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收藏
页码:931 / 942
页数:12
相关论文
共 72 条
[1]   IDENTIFICATION OF ELECTROPHYSIOLOGICALLY DISTINCT SUBPOPULATIONS OF RAT TASTE CELLS [J].
AKABAS, M ;
DODD, J ;
ALAWQATI, Q .
JOURNAL OF MEMBRANE BIOLOGY, 1990, 114 (01) :71-78
[2]   AMILORIDE-BLOCKABLE SODIUM CURRENTS IN ISOLATED TASTE RECEPTOR-CELLS [J].
AVENET, P ;
LINDEMANN, B .
JOURNAL OF MEMBRANE BIOLOGY, 1988, 105 (03) :245-255
[3]   NONINVASIVE RECORDING OF RECEPTOR CELL-ACTION POTENTIALS AND SUSTAINED CURRENTS FROM SINGLE TASTE-BUDS MAINTAINED IN THE TONGUE - THE RESPONSE TO MUCOSAL NACL AND AMILORIDE [J].
AVENET, P ;
LINDEMANN, B .
JOURNAL OF MEMBRANE BIOLOGY, 1991, 124 (01) :33-41
[4]  
AVENET P, 1992, SOC GEN PHY, V47, P271
[5]  
Avenet P, 1991, Curr Opin Neurobiol, V1, P198, DOI 10.1016/0959-4388(91)90078-L
[6]  
AVENET P, 1992, PENNINGTON CTR NUTRI, V2, P374
[7]   MEMBRANE CURRENTS IN TASTE CELLS OF THE RAT FUNGIFORM PAPILLA - EVIDENCE FOR 2 TYPES OF CA CURRENTS AND INHIBITION OF K-CURRENTS BY SACCHARIN [J].
BEHE, P ;
DESIMONE, JA ;
AVENET, P ;
LINDEMANN, B .
JOURNAL OF GENERAL PHYSIOLOGY, 1990, 96 (05) :1061-1084
[8]  
BEHE P, 1990, 10TH P INT S OLF TAS, P270
[9]   AMILORIDE - A MOLECULAR PROBE OF SODIUM-TRANSPORT IN TISSUES AND CELLS [J].
BENOS, DJ .
AMERICAN JOURNAL OF PHYSIOLOGY, 1982, 242 (03) :C131-C145
[10]  
BESTERMAN JM, 1985, J BIOL CHEM, V260, P1155