Physiological roles of renal potassium channels.

Potassium channels play an important role in a variety of transport operations in renal tubules. Considerable progress has been made in the analysis of their location and regulation by applying patch clamp techniques to native and cloned renal potassium channels. Potassium channels serve several functions, including the generation of the cell-negative potential and regulation of cell volume, particularly in the defense against cell swelling; they are also important for recycling and secretion of potassium. This review focuses on the properties of several potassium channels in the kidney and the important role in the regulation of potassium secretion in the distal nephron.