Abstract
Renal proximal tubular Na/phosphate cotransport is the key target in the control of renal phosphate handling. Using molecular tools for the type II Na/phosphate cotransporter, it could be documented that altered brush border membrane phosphate transport reflects a state of altered brush border expression of the specific transporter molecule. This alteration is either the consequence of specific membrane insertion/retrieval processes and/or reflects states of altered synthesisdegradation of the transporter.