Physiological and pharmacological agonists of the extracellular Ca2+ sensing receptor

Extracellular Ca2+ concentration [Ca2+](o) is vital for a number of processes varying from blood clotting to regulation membrane permeability and excitability. For this reason [Ca2+](o) is under strict control of a complex homeostatic system that includes parathyroid glands, kidneys, bones and intestine, The extracellular Ca2+ -sensing receptor is an essential component of this system, regulating parathyroid hormone secretion, Ca2+ (and Mg2+) excretion by the kidney, bone remodeling and Ca2+ reabsorption by the gastrointestinal tract. The Ca2+ -sensing receptor is also present in organs without an obvious link with mineral ion metabolism, This review will describe the discovery of a novel class of ion-sensing receptor(s), receptor-effector coupling and the roles of the Ca2+ -sensing receptor inside and outside the Ca2+. homeostatic system. (C) 2002 Elsevier Science B.V. All rights reserved.