Gut sensing of dietary K⁺ intake increases renal K⁺excretion

Am J Physiol Regul Integr Comp Physiol. 2011 Aug;301(2):R421-9. doi: 10.1152/ajpregu.00095.2011. Epub 2011 May 4.


Dietary K(+) intake may increase renal K(+) excretion via increasing plasma [K(+)] and/or activating a mechanism independent of plasma [K(+)]. We evaluated these mechanisms during normal dietary K(+) intake. After an overnight fast, [K(+)] and renal K(+) excretion were measured in rats fed either 0% K(+) or the normal 1% K(+) diet. In a third group, rats were fed with the 0% K(+) diet, and KCl was infused to match plasma [K(+)] profile to that of the 1% K(+) diet group. The 1% K(+) feeding significantly increased renal K(+) excretion, associated with slight increases in plasma [K(+)], whereas the 0% K(+) diet decreased K(+) excretion, associated with decreases in plasma [K(+)]. In the KCl-infused 0% K(+) diet group, renal K(+) excretion was significantly less than that of the 1% K(+) group, despite matched plasma [K(+)] profiles. We also examined whether dietary K(+) alters plasma profiles of gut peptides, such as guanylin, uroguanylin, glucagon-like peptide 1, and glucose-dependent insulinotropic polypeptide, pituitary peptides, such as AVP, α-MSH, and γ-MSH, or aldosterone. Our data do not support a role for these hormones in the stimulation of renal K(+) excretion during normal K(+) intake. In conclusion, postprandial increases in renal K(+) excretion cannot be fully accounted for by changes in plasma [K(+)] and that gut sensing of dietary K(+) is an important component of the regulation of renal K(+) excretion. Our studies on gut and pituitary peptide hormones suggest that there may be previously unknown humoral factors that stimulate renal K(+) excretion during dietary K(+) intake.

Publication types

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

MeSH terms

  • Aldosterone / blood
  • Aldosterone / metabolism
  • Amiloride / pharmacology
  • Animals
  • Blood Glucose
  • Gastrointestinal Tract / metabolism*
  • Gene Expression Regulation / physiology
  • Kidney / metabolism*
  • Male
  • Pituitary Hormones / genetics
  • Pituitary Hormones / metabolism
  • Postprandial Period
  • Potassium / blood*
  • Potassium / metabolism*
  • Potassium, Dietary / metabolism*
  • Rats
  • Rats, Wistar
  • Sodium / blood
  • Sodium Channel Blockers / pharmacology


  • Blood Glucose
  • Pituitary Hormones
  • Potassium, Dietary
  • Sodium Channel Blockers
  • Aldosterone
  • Amiloride
  • Sodium
  • Potassium