Endocrine Abstracts

The extracellular calcium-sensing receptor (CaR) plays a key role in the body's capacity to maintain a nearly constant level of the extracellular ionized calcium concentration. The parathyroid glands play an especially important role in calcium homeostasis through their capacity to sense even minute perturbations in the extracellular calcium concentration and to respond in ways that will normalize the level of extracellular calcium. In response to hypocalcemia, for example, in...

Bone is the major sink and store for calcium and it fulfils essential roles in the maintenance of extracellular free ionised calcium concentration ([Ca2+e)within its homeostatic range (1.1 to 1.3mM). In response to acute hypercalcaemia or hypocalcaemia, Ca2+ is rapidly transported into or out of bone. Bone turnover (and therefore bone Ca2+ turnover) achieves the long term correction of the [Ca2+e] by the metabolic actions of osteoblasts (i.e., bone-forming cells) and osteoclas...

Calcium homeostasis is a key element in bone development and in the maintenance of normal bone architecture. Bone acts in conjunction with the kidneys and the parathyroid glands to maintain circulating calcium levels. In times of excess it functions as a reservoir, but it is also able to donate calcium to the body when circulating levels are low and its structure and mineral content vary accordingly. The calcium sensing receptor (CaR) in both the parathyroid glands and in the ...