Dietary phosphorus is converted in the body to phosphates, in which form it exerts its widespread physiological functions, as an essential component of phospholipids, ATP, DNA, phosphorylated proteins, metabolic intermediates, body buffers, and bone. Phosphate homeostasis is dependent on the interaction of three organ systems — the gastrointestinal tract, the bone, and the kidneys — through the coordinated functions primarily of two hormones; parathyroid hormone (PTH) and vitamin D. Under conditions of low dietary phosphate intake, the intestine increases its absorptive efficiency to maximise phosphate absorption and the kidney increases renal phosphate transport to minimise urinary phosphate losses. The ability of the kidney to respond to acute increases or decreases in the filtered load of phosphate by altering excretion is well described. More intriguing is the intrinsic ability of the renal tubule cell to respond to alterations in body phosphate balance as a result of dietary availability or metabolic need.
KeywordsProximal Tubule Phosphate Transport Renal Handling Renal Phosphate Phosphate Homeostasis
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