Potassium transport in the maturing kidney

Pediatr Nephrol. 2007 Jul;22(7):915-25. doi: 10.1007/s00467-007-0432-3. Epub 2007 Mar 2.


The distal nephron and colon are the primary sites of regulation of potassium (K(+)) homeostasis, responsible for maintaining a zero balance in adults and net positive balance in growing infants and children. Distal nephron segments can either secrete or reabsorb K(+) depending on the metabolic needs of the organism. In the healthy adult kidney, K(+) secretion predominates over K(+) absorption. Baseline K(+) secretion occurs via the apical low-conductance secretory K(+) (SK) channel, whereas the maxi-K channel mediates flow-stimulated net urinary K(+) secretion. The K(+) retention characteristic of the neonatal kidney appears to be due not only to the absence of apical secretory K(+) channels in the distal nephron but also to a predominance of apical H-K-adenosine triphosphatase (ATPase), which presumably mediates K(+) absorption. Both luminal and peritubular factors regulate the balance between K(+) secretion and absorption. Perturbation in any of these factors can lead to K(+) imbalance. In turn, these factors may serve as effective targets for the treatment of both hyper-and hypokalemia. The purpose of this review is to present an overview of recent advances in our understanding of mechanisms of K(+) transport in the maturing kidney.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Extracellular Signal-Regulated MAP Kinases / metabolism
  • H(+)-K(+)-Exchanging ATPase / metabolism
  • Humans
  • Ion Transport / physiology
  • Kidney / growth & development
  • Kidney / metabolism*
  • Kidney Tubules, Collecting / growth & development
  • Kidney Tubules, Collecting / metabolism
  • Large-Conductance Calcium-Activated Potassium Channels / metabolism
  • Models, Biological
  • Potassium / metabolism*
  • Potassium Channels, Inwardly Rectifying / metabolism


  • Large-Conductance Calcium-Activated Potassium Channels
  • Potassium Channels, Inwardly Rectifying
  • Extracellular Signal-Regulated MAP Kinases
  • H(+)-K(+)-Exchanging ATPase
  • Potassium