[ Summary ] |
Blood calcium, phosphate, 1,25-dihydroxyvitamin D and fibroblast growth factor 23 (FGF23) have been shown to affect synthesis of the parathyroid hormone (PTH) An increase in blood calcium suppresses PTH synthesis and secretion, and induces the degradation of PTH protein in parathyroid cells through activation of a calciumsensing receptor. On the other hand, increased phosphate levels enhance PTH synthesis through stabilizing PTH mRNA. 1,25-dihydroxyvitamin D and FGF23 have been shown to suppress PTH synthesis. Through these mechanisms, circulatory PTH levels are tightly regulated. |