Towards a molecular view of renal proximal tubular reabsorption of phosphate.
Apical sodium-dependent transport of inorganic phosphate (Pi) in the proximal tubule plays a crucial role in renal Pi reabsorption and consequently in the maintenance of Pi homeostasis. This transport system represents a main target for acute and long-term regulation such as by parathyroid hormone, by growth factors and dietary intake of phosphate. In this short review we briefly describe the currently established cellular mechanism of proximal tubular Pi reabsorption and its regulation via the apical Na/Pi cotransport system. In a second part we will outline recent progress made with respect to the molecular cloning of renal Na/Pi cotransport systems. Knowledge about the molecular identity of these transport systems will make it possible to resolve yet unanswered questions about the molecular mechanisms involved in the physiology of the regulation of renal Pi reabsorption.
Biber
J
J
Institute of Physiology, University of Zürich, Switzerland.
Murer
H
H
D000042:Absorption; D000818:Animals; D006801:Humans; D007687:Kidney Tubules, Proximal / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism*
D010710:Phosphates