Ca2+ receptor from brain to gut:: Common stimulus, diverse actions

An extracellular Ca2--sensing receptor (CaR) plays central roles in Ca2+ homeostasis by regulating parathyroid hormone (PTH) secretion and venal Ca2+ handling. The CaR is also expressed in intestine and bone, where its functions in mineral metabolism are not yet well defined. The receptor is also present in various types of cells seemingly uninvolved in systemic mineral ion homeostasis (such as neuronal and glial cells in the brain and various epithelial cells), where ifs actions are poorly understood but might involve the regulation of local ionic homeostasis and/or diverse cellular processes, such as cellular differentiation and proliferation.