Pflügers Archiv

, Volume 377, Issue 3, pp 229–234 | Cite as

Impaired distal nephron acidification in chronically phosphate depleted rats

  • Theodore W. Kurtz
  • Chen H. Hsu
Transport Processes, Metabolism and Endocrinology; Kidney, Gastrointestinal Tract, and Exocrine Glands


Renal tubular bicarbonate reabsorption and acidification were evaluated in phosphate depleted rats (PD) and controls. After 33 days of phosphate depletion, urine pH of PD rats (N=5, 6.36±0.15) was significantly higher than control (N=5, 5.64±0.09,P<0.005) following an NH4Cl load. Urinary titratable acid of PD rats (9.6±1.8) was significantly reduced compared to control (117.2±19.7 μEq/3 h,P<0.001), whereas NH 4 + excretion was not different. The plasma HCO 3 thresholds at which bicarbonaturia occurred (approximately 25 mEq/l) were identical in controls and phosphate depleted rats during isotonic bicarbonate infusion. The higher urine pH of phosphate depleted rats following NH4Cl administration was not due to low urinary phosphate as 3-day phosphate depleted rats could normally acidify urine after NH4Cl (pH=5.86±0.09,N=6 vs. control 5.87±0.08,N=6,P=N.S.) despite urinary phosphate excretion as low as in 33-day PD rats. These data indicate the presence of impaired distal tubular acidification in chronically phosphate depleted rats.

Key words

Phosphates Acidosis, renal tubular Ammonium chloride Bicarbonate 


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  1. 1.
    Arruda, J. A. L., Nascimento, L., Mehta, P. K., Rademacher, D. R., Sehy, J. T., Westenfelder, C., Kurtzman, N. A.: The critical importance of urinary concentrating ability in the generation of urinary carbon dioxide tension. J. Clin. Invest.60, 922–935 (1977)Google Scholar
  2. 2.
    Chaney, A. L., Marbach, E. P.: Modified reagents for determination of urea and ammonia. Clin. Chem.8, 130–132 (1962)Google Scholar
  3. 3.
    Coburn, J. W., Massry, S. G.: Changes in serum and urinary calcium during phosphate depletion: Studies on mechanisms. J. Clin. Invest.49, 1073–1087 (1970)Google Scholar
  4. 4.
    Day, H. G., McCollum, E. V.: Mineral metabolism, growth, and symptomatology of rats on a diet extremely deficient in phosphorus. J. Biol. Chem.130, 260–283 (1939)Google Scholar
  5. 5.
    Dominguez, J. H., Gary, R. W., Lemann, J.: Dietary phosphate depletion in women and men: Effects on mineral and acid balances, parathyroid hormone and metabolism of 25-OH-Vitamin D. J. Clin. Endocrinol. Metab.43, 1056–1068 (1976)Google Scholar
  6. 6.
    Emmett, M., Goldfarb, S., Agus, Z. S., Narins, R. G.: The pathophysiology of acid-base changes in chronically phosphate-depleted rats. Bone-kidney interactions. J. Clin. Invest.59, 291–298 (1977)Google Scholar
  7. 7.
    Fourman, P., McConkey, B., Smith, J. W. G.: Defects of water reabsorption and hydrogen-ion exretion by the renal tubules in hyperparathyroidism. Lancet 1960I, 619–623Google Scholar
  8. 8.
    Gold, L. W., Massry, S. G., Arieff, A. I., Coburn, J. W.: Renal bicarbonate wasting during phosphate depletion. A possible cause of altered acid-base homeostasis in hyperparathyroidism. J. Clin. Invest.25, 2556–2562 (1973)Google Scholar
  9. 9.
    Gold, L. W., Massry, S. G., Friedler, R. M.: Effect of phosphate depletion on renal tubular reabsorption of glucose. J. Lab. Clin. Med.89, 554–559 (1977)Google Scholar
  10. 10.
    Goldfarb, S., Westby, G. R., Goldberg, M., Agus, Z. S.: Renal tubular effects of chronic phosphate depletion. J. Clin. Invest.59, 770–779 (1977)Google Scholar
  11. 11.
    Harter, H. R., Mercado, A., Rutherford, E., Rodriquez, H., Slatopolsky, E., Klahr, S.: Effects of phosphate depletion and parathyroid hormone on renal glucose reabsorption. Am. J. Physiol.227, 1422–1427 (1974)Google Scholar
  12. 12.
    Leonard, E., Orloff, J.: Regulation of ammonia excretion in the rat. Am. J. Physiol.182, 131–138 (1955)Google Scholar
  13. 13.
    Lippman, R. W.: Endogenous and exogenous creatinine clearances in the rat. Am. J. Physiol.151, 211–214 (1947)Google Scholar
  14. 14.
    Lotz, M., Zisman, E., Bartter, F. C.: Evidence for a phosphorus-depletion syndrome in man. N. Engl. J. Med.278, 409–415 (1968)Google Scholar
  15. 15.
    Morris, R. C. Jr.: Renal tubular acidosis: mechanisms, classification, and implications. New Engl. J. Med.281, 1405–1413 (1969)Google Scholar
  16. 16.
    Muldowney, F. P., Freaney, R., McGeeney, D.: Renal tubular acidosis and aminoaciduria in osteomalacia of dietary intestinal origin. Q. J. Med.37, 517–539 (1968)Google Scholar
  17. 17.
    Purkerson, M. L., Lubowitz, H., White, R. W., Bricker, N. S.: On the influence of extracellular fluid volume expansion on bicarbonate reabsorption in the rat. J. Clin. Invest.48, 1754–1760 (1969)Google Scholar
  18. 18.
    Roscoe, J. M., Goldstein, M. B., Halperin, M. L., Schloeder, F. X., Stinebaugh, B. J.: Effect of amphotericin B on urine acidification in rats: Implications for the pathogenesis of distal renal tubular acidosis. J. Lab. Clin. Med.89, 463–470 (1977)Google Scholar
  19. 19.
    Wrong, O., Davies, H. E. F.: The excretion of acid in renal disease. Q. J. Med.28, 259–313 (1959)Google Scholar
  20. 20.
    York, S. E., Yendt, E. R.: Osteomalacia associated with renal bicarbonate loss. Can. Med. Assoc. J.94, 1329–1342 (1966)Google Scholar

Copyright information

© Springer-Verlag 1978

Authors and Affiliations

  • Theodore W. Kurtz
    • 1
  • Chen H. Hsu
    • 1
  1. 1.Division of Nephrology, Department of Internal MedicineUniversity of MichiganAnn ArborUSA

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