TY - JOUR
T1 - Proton currents through amiloride-sensitive Na+ channels in isolated hamster taste cells
T2 - Enhancement by vasopressin and CAMP
AU - Gilbertson, Timothy A.
AU - Roper, Stephen D.
AU - Kinnamon, Sue C.
N1 - Funding Information:
This work was supported by NIH grants DC-00244, DC-00766 (S. C. K.), and DC-00374 (S. D. R.). The authors wish to express gratitude to Ms. Collin Ruiz and Ms. Ginger Sammonds for their expert technical assistance and to Mr. T. Cure m ings (Department of Anatomy and Neurobiology) and Mr. B. Evans (Biomedical Illustration and Communication program) for the illustrations in Figure 1.
PY - 1993/5
Y1 - 1993/5
N2 - 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, fungi-form taste receptor cells were examined using patch-clamp techniques. Approximately one-half of all cells had amiloride-sensitive Na+ currents (INa) with a Ki value near 0.2 μM 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 (IH+) with an extrapolated reversal potential near approximately +150 mV, which was completely blocked by amiloride (30 μM). Treatment of isolated taste cells with arginine8-vasopressin caused equivalent increases in both INa and IH+; 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.
AB - 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, fungi-form taste receptor cells were examined using patch-clamp techniques. Approximately one-half of all cells had amiloride-sensitive Na+ currents (INa) with a Ki value near 0.2 μM 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 (IH+) with an extrapolated reversal potential near approximately +150 mV, which was completely blocked by amiloride (30 μM). Treatment of isolated taste cells with arginine8-vasopressin caused equivalent increases in both INa and IH+; 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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U2 - 10.1016/0896-6273(93)90208-9
DO - 10.1016/0896-6273(93)90208-9
M3 - Article
C2 - 8388226
AN - SCOPUS:0027160276
VL - 10
SP - 931
EP - 942
JO - Neuron
JF - Neuron
SN - 0896-6273
IS - 5
ER -