Figure 1

CaSR is located on the basolateral membrane of the tubular cells in the thick ascendent limb of Henle loop and in the distal convoluted cortical tubule, where it senses serum calcium and reduces calcium reabsorption when activated by serum calcium increase. In proximal tubules and collecting ducts it is located on the apical membrane and its activation by the increase in tubular fluid calcium may protect against calcium-phosphate precipitation.