Cary R Boyd-Shiwarski1, Arohan R Subramanya. 1. aDepartment of Medicine, Renal-Electrolyte Division bDepartment of Cell Biology, University of Pittsburgh School of Medicine cVA Pittsburgh Healthcare System, Pittsburgh, Pennsylvania, USA.
Abstract
PURPOSE OF REVIEW: The current review combines past findings with recent advances in our understanding of the homeostatic response to potassium imbalance. RECENT FINDINGS: Following the ingestion of a dietary potassium load, a combination of extrarenal and renal mechanisms act to maintain extracellular K+ within a tight window. Through hormonal regulation and direct K+ sensing, the nephron is ideally suited to respond to wide shifts in external K+ balance. Current evidence indicates that dietary K+ loading triggers a coordinated kaliuretic response that appears to involve voltage-dependent changes in sodium transport across multiple nephron segments, including the proximal tubule, medullary loop of Henle, and distal tubule. Inhibition of sodium transport in these segments would accomplish the final goal of enhancing distal NaCl delivery, luminal flow, and K+ secretion in the aldosterone sensitive distal nephron (ASDN). SUMMARY: Ongoing research seeks to define the relationship between potassium and volume homeostasis by elucidating pathways that couple renal K+ sensing and tubular function during the potassium stress response.
PURPOSE OF REVIEW: The current review combines past findings with recent advances in our understanding of the homeostatic response to potassium imbalance. RECENT FINDINGS: Following the ingestion of a dietary potassium load, a combination of extrarenal and renal mechanisms act to maintain extracellular K+ within a tight window. Through hormonal regulation and direct K+ sensing, the nephron is ideally suited to respond to wide shifts in external K+ balance. Current evidence indicates that dietary K+ loading triggers a coordinated kaliuretic response that appears to involve voltage-dependent changes in sodium transport across multiple nephron segments, including the proximal tubule, medullary loop of Henle, and distal tubule. Inhibition of sodium transport in these segments would accomplish the final goal of enhancing distal NaCl delivery, luminal flow, and K+ secretion in the aldosterone sensitive distal nephron (ASDN). SUMMARY: Ongoing research seeks to define the relationship between potassium and volume homeostasis by elucidating pathways that couple renal K+ sensing and tubular function during the potassium stress response.
Authors: Cary R Boyd-Shiwarski; Claire J Weaver; Rebecca T Beacham; Daniel J Shiwarski; Kelly A Connolly; Lubika J Nkashama; Stephanie M Mutchler; Shawn E Griffiths; Sophia A Knoell; Romano S Sebastiani; Evan C Ray; Allison L Marciszyn; Arohan R Subramanya Journal: Am J Physiol Renal Physiol Date: 2020-04-13
Authors: Cary R Boyd-Shiwarski; Daniel J Shiwarski; Ankita Roy; Hima N Namboodiri; Lubika J Nkashama; Jian Xie; Kara L McClain; Allison Marciszyn; Thomas R Kleyman; Roderick J Tan; Donna B Stolz; Manojkumar A Puthenveedu; Chou-Long Huang; Arohan R Subramanya Journal: Mol Biol Cell Date: 2017-12-13 Impact factor: 4.138