Skip to main content
PMC home page
The Journal of Clinical Investigation logoLink to The Journal of Clinical Investigation
. 1990 Jul;86(1):32–39. doi: 10.1172/JCI114702

Effect of bath and luminal potassium concentration on ammonia production and secretion by mouse proximal tubules perfused in vitro.

G T Nagami 1
PMCID: PMC296686  PMID: 2164046

Abstract

To determine the effects of acute changes in K+ concentration in vitro on ammonia production and secretion by the proximal tubule, we studied mouse S2 segments perfused with and bathed in Krebs-Ringer bicarbonate buffers containing various K+ concentrations. All bath solutions contained L-glutamine as the ammoniagenic substrate. High bath and luminal K+ concentrations (8 mM), but not high luminal K+ concentration alone, inhibited total ammonia production rates by 26%, while low bath and luminal K+ concentrations (2 mM), but not low luminal K+ concentration alone, stimulated total ammonia production rates by 33%. The stimulation of ammonia production by low bath K+ concentration was not observed when L-glutamine was added to the luminal perfusion solution. On the other hand, high luminal K+ concentration stimulated, while low luminal K+ concentration inhibited, net luminal secretion of total ammonia in a way that was: (a) independent of total ammonia production rates, (b) independent of Na(+)-H+ exchange activity, and (c) not due to changes in transepithelial fluxes of total ammonia. These results suggest that luminal potassium concentration has a direct effect on cell-to-lumen transport of ammonia.

Full text

PDF
33

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. BAERTL J. M., SANCETTA S. M., GABUZDA G. J. Relation of acute potassium depletion to renal ammonium metabolism in patients with cirrhosis. J Clin Invest. 1963 May;42:696–706. doi: 10.1172/JCI104761. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Garvin J. L., Burg M. B., Knepper M. A. Ammonium replaces potassium in supporting sodium transport by the Na-K-ATPase of renal proximal straight tubules. Am J Physiol. 1985 Nov;249(5 Pt 2):F785–F788. doi: 10.1152/ajprenal.1985.249.5.F785. [DOI] [PubMed] [Google Scholar]
  3. Garvin J. L., Burg M. B., Knepper M. A. NH3 and NH4+ transport by rabbit renal proximal straight tubules. Am J Physiol. 1987 Feb;252(2 Pt 2):F232–F239. doi: 10.1152/ajprenal.1987.252.2.F232. [DOI] [PubMed] [Google Scholar]
  4. Good D. W. Effects of potassium on ammonia transport by medullary thick ascending limb of the rat. J Clin Invest. 1987 Nov;80(5):1358–1365. doi: 10.1172/JCI113213. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Kamm D. E., Strope G. L. Glutamine and glutamate metabolism in renal cortex from potassium-depleted rats. Am J Physiol. 1973 Jun;224(6):1241–1248. doi: 10.1152/ajplegacy.1973.224.6.1241. [DOI] [PubMed] [Google Scholar]
  6. Kurtz I., Balaban R. S. Ammonium as a substrate for Na+-K+-ATPase in rabbit proximal tubules. Am J Physiol. 1986 Mar;250(3 Pt 2):F497–F502. doi: 10.1152/ajprenal.1986.250.3.F497. [DOI] [PubMed] [Google Scholar]
  7. Nagami G. T., Kurokawa K. Regulation of ammonia production by mouse proximal tubules perfused in vitro. Effect of luminal perfusion. J Clin Invest. 1985 Mar;75(3):844–849. doi: 10.1172/JCI111781. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Nagami G. T. Luminal secretion of ammonia in the mouse proximal tubule perfused in vitro. J Clin Invest. 1988 Jan;81(1):159–164. doi: 10.1172/JCI113287. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Nagami G. T., Sonu C. M., Kurokawa K. Ammonia production by isolated mouse proximal tubules perfused in vitro. Effect of metabolic acidosis. J Clin Invest. 1986 Jul;78(1):124–129. doi: 10.1172/JCI112540. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Pagliara A. S., Goodman A. D. Relation of renal cortical gluconeogenesis, glutamate content, and production of ammonia. J Clin Invest. 1970 Nov;49(11):1967–1974. doi: 10.1172/JCI106416. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Pishak M. R., Phillips A. T. A modified radioisotopic assay for measuring glutamine synthetase activity in tissue extracts. Anal Biochem. 1979 Apr 1;94(1):82–88. doi: 10.1016/0003-2697(79)90793-0. [DOI] [PubMed] [Google Scholar]
  12. Sastrasinh S., Tannen R. L. Effect of potassium on renal NH3 production. Am J Physiol. 1983 Apr;244(4):F383–F391. doi: 10.1152/ajprenal.1983.244.4.F383. [DOI] [PubMed] [Google Scholar]
  13. Silbernagl S. Tubular reabsorption of L-glutamine studied by free-flow micropuncture and microperfusion of rat kidney. Int J Biochem. 1980;12(1-2):9–16. doi: 10.1016/0020-711x(80)90034-8. [DOI] [PubMed] [Google Scholar]
  14. Simon E. E., Fry B., Hering-Smith K., Hamm L. L. Ammonia loss from rat proximal tubule in vivo: effects of luminal pH and flow rate. Am J Physiol. 1988 Nov;255(5 Pt 2):F861–F867. doi: 10.1152/ajprenal.1988.255.5.F861. [DOI] [PubMed] [Google Scholar]
  15. Sleeper R. S., Belanger P., Lemieux G., Preuss H. G. Effects of in vitro potassium on ammoniagenesis in rat and canine kidney tissue. Kidney Int. 1982 Feb;21(2):345–353. doi: 10.1038/ki.1982.28. [DOI] [PubMed] [Google Scholar]
  16. Szylman P., Better O. S., Chaimowitz C., Rosler A. Role of hyperkalemia in the metabolic acidosis of isolated hypoaldosteronism. N Engl J Med. 1976 Feb 12;294(7):361–365. doi: 10.1056/NEJM197602122940703. [DOI] [PubMed] [Google Scholar]
  17. Tannen R. L. Relationship of renal ammonia production and potassium homeostasis. Kidney Int. 1977 Jun;11(6):453–465. doi: 10.1038/ki.1977.63. [DOI] [PubMed] [Google Scholar]
  18. Tannen R. L. The effect of uncomplicated potassium depletion on urine acidification. J Clin Invest. 1970 Apr;49(4):813–827. doi: 10.1172/JCI106295. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Tannen R. L., Wedell E., Moore R. Renal adaptation to a high potassium intake. The role of hydrogen ion. J Clin Invest. 1973 Sep;52(9):2089–2101. doi: 10.1172/JCI107394. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Journal of Clinical Investigation are provided here courtesy of American Society for Clinical Investigation

RESOURCES