Some characteristics of sodium-independent phosphate transport across renal basolateral membranes

Biochim Biophys Acta. 1991 May 7;1064(2):229-34. doi: 10.1016/0005-2736(91)90306-s.

Abstract

Sodium-independent phosphate transport was evaluated in porcine renal basolateral membrane vesicles. Phosphate uptake was saturable with an apparent Km 10.1 +/- 1.2 mM and Vmax 13.6 +/- 2.0 nmol (mg protein)-1 min-1, n = 5. Phosphate uptake was trans-stimulated with intravesicle phosphate and was enhanced with a positive transmembrane electrical potential. Arsenate and bicarbonate inhibited phosphate transport but other anions including sulfate and phosphonoformate were without effect. These studies indicate that phosphate uptake across basolateral membranes is present in the absence of sodium, is facilitated, and is specific for phosphate. The apparent affinity and rate of phosphate transport across the basolateral membrane is significantly higher than the respective parameters observed for the brush-border membrane.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arsenates / pharmacology
  • Bicarbonates / pharmacology
  • Biological Transport
  • Cell Membrane / metabolism*
  • Kidney Cortex / drug effects
  • Kidney Cortex / metabolism*
  • Kinetics
  • Membrane Potentials / drug effects
  • Phosphates / metabolism*
  • Sodium / pharmacology
  • Structure-Activity Relationship
  • Swine

Substances

  • Arsenates
  • Bicarbonates
  • Phosphates
  • Sodium
  • arsenic acid