Phosphate and Glucose Transport in the Proximal Convoluted Tubule: Mutual Dependency on Sodium

Abstract

The possibility that diverse solutes such as glucose and amino acids may influence phosphate transport in the proximal renal tubule (1) has provided a basis for various theories regarding the mechanism of phosphate absorption. Such theories may include a polyfunctional carrier, a common, limited energy source or shared driving forces. Thus, as with other epithelia (2), absorptive processes in the proximal convoluted tubule may share a common element such as coupling to sodium transport. In this regard, the present studies were designed to examine the relationship between glucose and phosphate absorption in isolated proximal convoluted tubules from the rabbit kidney and to document that sodium transport is necessary for the renal absorption of both these solutes.