Combined K+ and Cl- repletion corrects augmented H+ secretion by distal tubules in chronic alkalosis

Am J Physiol. 1994 Apr;266(4 Pt 2):F592-603. doi: 10.1152/ajprenal.1994.266.4.F592.


NaCl administration enhances HCO3 secretion in the distal tubule of animals with chronic metabolic alkalosis but does not correct the augmented H+ secretion characteristic of this disorder. The present studies used in vivo microperfusion micropuncture to investigate whether combined repletion of K+ and Cl- corrected the augmented H+ secretion in the distal tubule of rats with chronic furosemide-induced metabolic alkalosis. Correction of alkalosis was induced in one group of animals with NaCl and in another group with a similar amount of Cl- as NaCl + KCl for 24 h; each group was compared with animals with maintained alkalosis. Total 24-h urine HCO3 excretion by each Cl(-)-repleted group comprised > or = 70% of the calculated HCO3 loss necessary to induce the respective decrease in plasma total CO2. Alkalotic animals given NaCl+KCl had significantly lower H+ secretion in the distal tubule compared with animals with maintained alkalosis (15.5 +/- 1.2 vs. 34.6 +/- 1.8, P < 0.01) but those given only NaCl did not (28.3 +/- 1.5, P = 0.14). H+ secretion was not different among control animals given similar amounts of Na+, K+, and Cl-. These studies demonstrate that Cl- repletion corrects chronic furosemide-induced metabolic alkalosis predominantly by a renal mechanism and that combined administration of K+ and Cl-, but not of Cl- alone, corrects the augmented H+ secretion in the distal tubule in this model of chronic alkalosis.

Publication types

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

MeSH terms

  • Alkalosis / blood
  • Alkalosis / metabolism*
  • Alkalosis / urine
  • Animals
  • Chlorides / metabolism*
  • Chronic Disease
  • Electrolytes / metabolism
  • Female
  • Hydrogen / metabolism*
  • Kidney Tubules, Distal / metabolism*
  • Male
  • Potassium / metabolism*
  • Punctures
  • Rats
  • Rats, Wistar
  • Time Factors


  • Chlorides
  • Electrolytes
  • Hydrogen
  • Potassium