A voltage-activated proton current in human cardiac fibroblasts

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• 作者：Antoun El Chemaly ; Romain Guinamard ; Marie Demion ; Nassim Fares ; Victor Jebara ; Jean-Franç ; ois Faivre and Patrick Bois
• 关键词：Proton currents ; Membrane potential ; Cardiac fibroblasts ; Ischemia
• 刊名：Biochemical and Biophysical Research Communications
• 出版年：2006
• 出版时间：10 February 2006
• 年：2006
• 卷：340
• 期：2
• 页码：512-516
• 全文大小：155 K

文摘

A voltage-activated proton current in human cardiac fibroblasts, measured using the whole-cell recording configuration of the patch-clamp technique, is reported. Increasing the pH of the bathing solution shifted the current activation threshold to more negative potentials and increased both the current amplitude and its rate of activation. Changing the pH gradient by one unit caused a 51 mV shift in the reversal potential of the current, demonstrating a high selectivity for protons of the channel carrying the current. Extracellularly applied Zn²⁺ reversibly inhibited the current. Activation of the current contributes to the resting membrane conductance under conditions of intracellular acidosis. It is proposed that this current in cardiac fibroblasts is involved in the regulation of the intracellular pH and the membrane potential under physiological conditions as well as in response to pathological conditions such as ischemia.