Review ArticleCalcimimetic agents and the calcium-sensing receptorCoburn, Jack W.; Maung, Hla M.Author Information The Medical and Research Services, Veterans Affairs West Los Angeles Healthcare Center, Los Angeles, CA, USA; and Department of Medicine, UCLA School of Medicine, Los Angeles, CA, USA orrespondence to Jack W. Coburn, MD, Nephrology Section (111L), V.A. West Los Angeles Healthcare Center, 11301 Wilshire Boulevard, Los Angeles, CA 90073, USA Current Opinion in Nephrology and Hypertension: March 2000 - Volume 9 - Issue 2 - p 123-132 Buy Abstract Blood ionized extracellular calcium is closely regulated. To accomplish this, a hormone-like receptor that is responsive to extracellular ionized calcium regulates both the secretion of parathyroid hormone and the excretion of urinary calcium (as well as other cellular processes). Several hereditary disorders have mutations that cause either loss or gain of function of the calcium-sensing receptor, and alterations of the calcium-sensing receptor may play a role in both primary and secondary hyperparathyroidism. Calcimimetics are agents that act to make the calcium-sensing receptor more sensitive to extracellular ionized calcium; thereby they suppress the secretion of parathyroid hormone. Early trials in animal models of secondary hyperparathyroidism and in patients with primary hyperparathyroidism or with uremic secondary hyperparathyroidism have shown that the first generation calcimimetic, R-568, effectively lowers parathyroid hormone levels and is well tolerated. © 2000 Lippincott Williams & Wilkins, Inc.