Abstract
Inorganic phosphate (Pi) is an essential nutrient for several biological functions, including intracellular signal transduction, the production and function of cell membranes, and energy exchange. The maintenance of constant circulating levels of Pi depends on the coordinated activity of three major organs: the intestine, the kidney, and the bones. To achieve these functions, a transport system is required to transfer Pi across hydrophobic cell membranes. Parathyroid hormone (PTH) and 1,25-dihydroxyvitamin D3 are also regulators of Pi homeostasis, and recent studies have identified other factors that contribute to the maintenance of Pi homeostasis, including first phosphatonins [fibroblast growth factor (FGF) 23] originated from osteocytes established the concept of the bone-kidney axis. In this review, we discuss Pi homeostasis through several tissues.
