Renal potassium physiology: integration of the renal response to dietary potassium depletion.

We summarize the current understanding of the physiology of the renal handling of potassium (K), and present an integrative view of the renal response to K depletion caused by dietary K restriction. This renal response involves contributions from different nephron segments, and aims to diminish the rate of excretion of K as a result of: decreasing the rate of electrogenic (and increasing the rate of electroneutral) reabsorption of sodium in the aldosterone-sensitive distal nephron (ASDN), decreasing the abundance of renal outer medullary K channels in the luminal membrane of principal cells in the ASDN, decreasing the flow rate in the ASDN, and increasing the reabsorption of K in the cortical and medullary collecting ducts. The implications of this physiology for the association between K depletion and hypertension, and K depletion and formation of calcium kidney stones are discussed.