Interactions Between Phosphate Transport and Oxidative Metabolism in the Rabbit Proximal Tubule

Abstract

In proximal renal tubules, inorganic phosphate is both a transported solute and a substrate for intracellular metabolism. While these two functions may involve separate pools of phosphate, it is more likely that there is some interaction between phosphate transport and the metabolic processes which use inorganic phosphate. Within the proximal tubular cell, several types of metabolic processes involve inorganic phosphate. Glycolysis and oxidative phosphorylation utilize inorganic phosphate in the production of ATP. On the other hand, gluconeo-genesis and the sodium-potassium ATPase hydrolyze ATP to generate inorganic phosphate. Furthermore, the intracellular concentration of inorganic phosphate may contribute to the phosphorylation potential, i.e. [ATP]/[ADP]·[Pi], which regulates the rates of these metabolic processes.