Mineralocorticoid effect on K+ permeability of the rabbit cortical collecting tubule

Kidney Int. 1985 Oct;28(4):640-5. doi: 10.1038/ki.1985.177.


Mineralocorticoid hormones stimulate Na+ absorption and K+ secretion by the cortical collecting tubule. There is good evidence that this stimulation involves increasing luminal membrane Na+ permeability and the turnover rate (or number) of the Na+-K+ pumps. These experiments were designed to examine whether mineralocorticoid hormones also increase cell K+ permeability. Using 42K tracer measurements in tubules treated with amiloride to inhibit active Na+ and K+ transport, passive K+ permeation increased with increasing mineralocorticoid effect. Net Na+ absorption and the (passive) K+ efflux rate coefficient (KK) showed a linear relationship. The stimulatory effect was evident in vitro since 0.2 microM aldosterone added to the bath of tubules harvested from NaCl-loaded rabbits increased KK at 3 hrs while time controls showed no change. Since these tubules were also treated with amiloride, this increase in KK was not dependent on increasing Na+ absorption. The results indicate that in addition to the well-described effects of aldosterone on Na+ permeability and cell metabolism, the mineralcorticoid effect includes an increase in cellular K+ permeability.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aldosterone / pharmacology*
  • Amiloride / pharmacology
  • Animals
  • Biological Transport / drug effects
  • Biological Transport, Active / drug effects
  • Desoxycorticosterone / pharmacology*
  • Female
  • In Vitro Techniques
  • Kidney Tubules / physiology*
  • Kidney Tubules, Collecting / physiology*
  • Ouabain / pharmacology
  • Permeability
  • Potassium / physiology*
  • Rabbits
  • Sodium-Potassium-Exchanging ATPase / antagonists & inhibitors


  • Desoxycorticosterone
  • Aldosterone
  • Ouabain
  • Amiloride
  • Sodium-Potassium-Exchanging ATPase
  • Potassium