Gut Sensing of Potassium Intake and its Role in Potassium Homeostasis

Extracellular K+ homeostasis has been explained by feedback mechanisms in which changes in extracellular K+ concentration drive renal K+ excretion directly or indirectly via stimulating aldosterone secretion. However, this cannot explain meal-induced kaliuresis, which often occurs without increases in plasma K+ or aldosterone concentrations. Recent studies have produced evidence supporting a feedforward control in which gut sensing of dietary K+ increases renal K+ excretion (and extrarenal K+ uptake) independent of plasma K+ concentrations, namely, a gut factor. This review focuses on these new findings and discusses the role of gut factor in acute and chronic regulation of extracellular K+ as well as in the beneficial effects of high K+ intake on the cardiovascular system. (C) 2013 Elsevier Inc. All rights reserved.