ELECTROPHYSIOLOGICAL ANALYSIS OF NA+/P-I COTRANSPORT MEDIATED BY A TRANSPORTER CLONED FROM RAT-KIDNEY AND EXPRESSED IN XENOPUS-OOCYTES

被引：81

作者：

BUSCH, A ^{[1
]}

WALDEGGER, S ^{[1
]}

HERZER, T ^{[1
]}

BIBER, J ^{[1
]}

MARKOVICH, D ^{[1
]}

HAYES, G ^{[1
]}

MURER, H ^{[1
]}

LANG, F ^{[1
]}

机构：

[1] UNIV ZURICH,INST PHYSIOL,CH-8057 ZURICH,SWITZERLAND

来源：

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA | 1994年 / 91卷 / 17期

关键词：

D O I：

10.1073/pnas.91.17.8205

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

Phosphate (P-i) reabsorption in renal proximal tubules involves Na+/P-i cotransport across the brush border membrane; its transport rate is influenced by the Na+-coupled transport of other solutes as well as by pH. In the present study, we have expressed a cloned rat renal brush border membrane Na+/P-i cotransporter (NaPi-2) in Xenopus laevis oocytes and have analyzed its electrophysiologic properties in voltage- and current-clamp studies. Addition of P-i to Na+-containing superfusates resulted in a depolarization of the membrane potential and, in voltage-clamped oocytes, in an inward current (I-p), An analysis of the Na+ and/or P-i concentration dependence of I-p suggested a Na+/P-i stoichiometry of 3:1. I-p was increased by increasing the pH of the superfusate; this phenomenon seems to be mainly related to a lowering of the affinity for Na+ interaction by increasing H+ concentration. The present data suggest that known properties of P-i handling at the tubular/membrane level are ''directly'' related to specific characteristics of the transport molecule (NaPi-2) involved.

引用

页码：8205 / 8208

页数：4

共 33 条

[1] EFFECT OF PH ON PHOSPHATE-TRANSPORT IN RAT RENAL BRUSH-BORDER MEMBRANE-VESICLES [J].