AUTHOR=Lasaad Samia , Crambert Gilles TITLE=Renal K+ retention in physiological circumstances: focus on adaptation of the distal nephron and cross-talk with Na+ transport systems JOURNAL=Frontiers in Physiology VOLUME=14 YEAR=2023 URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2023.1264296 DOI=10.3389/fphys.2023.1264296 ISSN=1664-042X ABSTRACT=

Consumption of salt (NaCl) and potassium (K⁺) has been completely modified, switching from a rich-K⁺/low-NaCl diet in the hunter–gatherer population to the opposite in the modern, westernized population. The ability to conserve K⁺ is crucial to maintain the plasma K⁺ concentration in a physiological range when dietary K⁺ intake is decreased. Moreover, a chronic reduction in the K⁺ intake is correlated with an increased blood pressure, an effect worsened by a high-Na⁺ diet. The renal adaptation to a low-K⁺ diet in order to maintain the plasma K⁺ level in the normal range is complex and interconnected with the mechanisms of the Na⁺ balance. In this short review, we will recapitulate the general mechanisms allowing the plasma K⁺ value to remain in the normal range, when there is a necessity to retain K⁺ (response to low-K⁺ diet and adaptation to gestation), by focusing on the processes occurring in the most distal part of the nephron. We will particularly outline the mechanisms of K⁺ reabsorption and discuss the consequences of its absence on the Na⁺ transport systems and the regulation of the extracellular compartment volume and blood pressure.