Renal collecting duct physiology and pathophysiology 1.

In the kidney, the collecting duct (CD) is composed of at least four cell types: principal, type-A intercalated cells (IC), type-B IC, and non-A and non-B IC. Although this heterogeneous composition has been recognized since the end of the nineteenth century, the physiological role of the various cell types in the CD continues to be deciphered as of today. Principal and ICs are essential in ion-water balance and acid-base homeostasis, respectively. However, recent research has revealed a striking interplay and overlap between the specific functions of these cell types. This review summarizes the recent findings on CD cells and their role in multiple pathophysiologies.