PROTON MODULATION OF M-LIKE POTASSIUM CURRENT (I-KX) IN ROD PHOTORECEPTORS
PROTON MODULATION OF M-LIKE POTASSIUM CURRENT (I-KX) IN ROD PHOTORECEPTORS
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DOI：
10.1016/0304-3940(94)90324-7
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发表时间：
1994-04-11
影响因子：
2.5
通讯作者：
BARNES, S
中科院分区：
文献类型：
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作者：
KURENNY, DE;BARNES, S
研究了细胞外pH(pH(E)6.9~8.1)和细胞内pH(pH(I)6.4~8.1)对膜片钳条件下非失活电压敏感性类M钾电流(I-Kx)的影响。I-Kx活化曲线的中点每pH(E)单位移动6.6 mV，其中酸化产生正移，碱化产生负移。I-Kx活化时间常数随pH(E)的变化与活化曲线的变化相一致。最大电导和门控电荷不受pH(E)变化的影响。I-Kx不依赖于pH(I)。鉴于i-kx在杆功能中的重要性，这些结果表明，pH(E)可能通过改变i-kx激活参数来影响杆传递的信号。
The effect of extracellular pH (pH(e) 6.9-8.1) and intracellular pH (pH(i) 6.4-8.1) on the non-inactivating voltage-sensitive M-like potassium current (I-Kx) was studied in patch-clamped salamander rod photoreceptors. The midpoint of the I-Kx activation curve shifted by 6.6 mV per pH(e) unit, with acidification producing positive shifts and alkalinization producing negative shifts. The time constant of I-Kx activation shifted with pH(e) in a manner consistent with the shifts in the activation curve. Maximum conductance and gating charge were unaffected by changes in pH(e). I-Kx did not depend on pH(i). Given the importance of I-Kx in rod function, these results suggest that pH(e) could affect the signal transmitted from rods by changing I-Kx activation parameters.