Renal PhysiologyCollecting Duct Intercalated Cell Function and RegulationRoy, Ankita*; Al-bataineh, Mohammad M.*; Pastor-Soler, Núria M.*,† Author Information *Renal-Electrolyte Division, Department of Medicine; and †Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania A.R. and M.M.A. contributed equally to this work. Correspondence: Dr. Núria M. Pastor-Soler, Renal-Electrolyte Division, A915 Scaife Hall, 3550 Terrace Street, Pittsburgh, PA 15261. Email: [email protected] Clinical Journal of the American Society of Nephrology 10(2):p 305-324, February 2015. | DOI: 10.2215/CJN.08880914 Buy Metrics Abstract Intercalated cells are kidney tubule epithelial cells with important roles in the regulation of acid-base homeostasis. However, in recent years the understanding of the function of the intercalated cell has become greatly enhanced and has shaped a new model for how the distal segments of the kidney tubule integrate salt and water reabsorption, potassium homeostasis, and acid-base status. These cells appear in the late distal convoluted tubule or in the connecting segment, depending on the species. They are most abundant in the collecting duct, where they can be detected all the way from the cortex to the initial part of the inner medulla. Intercalated cells are interspersed among the more numerous segment-specific principal cells. There are three types of intercalated cells, each having distinct structures and expressing different ensembles of transport proteins that translate into very different functions in the processing of the urine. This review includes recent findings on how intercalated cells regulate their intracellular milieu and contribute to acid-base regulation and sodium, chloride, and potassium homeostasis, thus highlighting their potential role as targets for the treatment of hypertension. Their novel regulation by paracrine signals in the collecting duct is also discussed. Finally, this article addresses their role as part of the innate immune system of the kidney tubule. Copyright © 2015 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.