Description
The cloning of an extracellular calcium (Ca2
o)sensing
receptor (CaR) from the parathyroid, kidney and other cell
types has clarified the mechanisms through which (Ca2
o)
exerts its direct actions on various cells and tissues. The
receptor enables the parathyroid cells to sense minute changes
in Ca2
o and to respond by changes in parathyroid hormone
(PTH) secretion in the opposite direction. In the kidney, it
mediates direct inhibition of the reabsorption of Ca2 (and
Mg2 ) in the cortical thick ascending limb. The
identification of inherited diseases of Ca2
o -sensing that arise
from mutations in the CaR gene [familial benign
hypocalciuric hypercalcaemia (FBHH), neonatal severe
hyperparathyroidism (NSHPT) and autosomal dominant
hypocalcaemia with hypercalciuria (ADHH)] has resulted
in the understanding of the central role of CaR in the
regulation of calcium homeostasis.
