| [ Summary ] |
Phosphate homeostasis is primarily regulated by the kidneys, bones, and intestines. Renal proximal reabsorption of phosphate is regulated by controlling the amount of NaPi-IIa, NaPi-IIc cotransporters in the brush border membrane of proximal tubules, and is adjusted by PTH and vitamin D. It was also found that phosphorous adjustment was carried out because phosphorous transportation carriers changed during periods of growth. Recently, fibroblast growth factor 23 (FGF23) has been cloned. FGF23 causes phosphorous diuresis by direct action or by acting on phosphorous carriers through vitamin D indirectly. The klotho protein forms an FGF23 acceptor. This complex causes effects related to manifestation of FGF23. Further elucidation is expected in future. |