An Integrated View of Potassium Homeostasis

To the Editor: The review article by Gumz et al. (July 2 issue) 1 on renal potassium handling focuses on the cortical collecting duct. We would emphasize the emerging recognition of the role of the distal convoluted tubule in potassium homeostasis. Dietary potassium was recently shown to rapidly (within minutes) inactivate the sodium–chloride cotransporter in the distal convoluted tubule. 2 This induced natriuresis and kaliuresis, probably by increasing sodium delivery to potassium secretory segments. 2 Because aldosterone does not mediate this process, 2 it is part of the feed-forward kaliuretic reflex. 1 In another study, potassium-induced natriuresis was preserved in a model of depletion of . . .