Intracellular pH shifts in cultured kidney (A6) cells: effects on apical Na+ transport

Author:

Zeiske Wolfgang1,Smets Ilse2,Ameloot Marcel2,Steels Paul2,van Driessche Willy1

Affiliation:

1. Laboratory of Physiology, Katholieke Universiteit Leuven, Campus Gasthuisberg, B-3000 Leuven, Belgium

2. Laboratory of Physiology, Limburgs Universitair Centrum, B-3590 Diepenbeek; and

Abstract

We report, for the epithelial Na+ channel (ENaC) in A6 cells, the modulation by cell pH (pHc) of the transepithelial Na+ current ( I Na), the current through the individual Na+channel ( i), the open Na+ channel density ( N o), and the kinetic parameters of the relationship between I Na and the apical Na+ concentration. The i and N o were evaluated from the Lorentzian I Na noise induced by the apical Na+ channel blocker 6-chloro-3,5-diaminopyrazine-2-carboxamide. pHc shifts were induced, under strict and volume-controlled experimental conditions, by apical/basolateral NH4Cl pulses or basolateral arrest of the Na+/H+exchanger (Na+ removal; block by ethylisopropylamiloride) and were measured with the pH-sensitive probe 2′,7′-bis(2-carboxyethyl)-5(6)-carboxyfluorescein. The changes in pHc were positively correlated to changes in I Na and the apically dominated transepithelial conductance. The sole pHc-sensitive parameter underlying I Na was N o. Only the saturation value of the I Na kinetics was subject to changes in pHc. pHc-dependent changes in N o may be caused by influencing P o, the ENaC open probability, or/and the total channel number, N T = N o/ P o.

Publisher

American Physiological Society

Subject

Cell Biology,Physiology

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3