Regulation of Na/Pi transporter in the proximal tubule

Research findings indicate that urinary excretion of inorganic phosphate is regulated by the amount of the sodium/phosphate-cotransporter, NAPi-IIa, in the brush border membrane of proximal tubular cells. Data reveal that the amount of NaPi-IIa is dependent on the insertion rates of the newly synthesized cotransporters and by the endocytic rate. Furthermore, phosphate reabsorption is influenced by changes in the hormonally- and protein kinase regulated endocytic rate.