Summary
The acute effect of bicarbonate infusion on inorganic phosphate (Pi) reabsorption was determined in thyroparathyroidectomized (TPTX) rats stabilized on a high phosphorus diet. In the normophosphatemic state, bicarbonate did not affect Pi reabsorption significantly. On the other hand, after hyperphosphatemia was induced by phosphate loading, bicarbonate inhibited Pi reabsorption. In order to determine if the absolute level of plasma or filtered Pi was an important determinant of this phosphaturic action of bicarbonate during hyperphosphatemia, equivalent rates of Pi reabsorption were achieved after phosphate infusion in TPTX rats previously stabilized on a low dietary phosphorus intake, but at significantly lower plasma Pi concentrations and filtered Pi loads than in their high dietary phosphorus counterparts. Bicarbonate inhibited Pi reabsorption equivalently in both hyperphosphatemic groups, indicating that the magnitude of Pi transport itself was of importance in determining the inhibitory response to bicarbonate. In addition, the results suggest that transport mechanisms for bicarbonate and Pi may interact competitively.
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References
Bank, N., Aynedjian, H. S., Weinstein, S. W.: A microperfusion study of phosphate reabsorption by the rat proximal renal tubule. Effect of parathyroid hormone. J. Clin. Invest.54, 1040–1048 (1974)
Baumann, K., Rumrich, G., Papavassiliou, F., Kloss, S.: pH dependence of phosphate reabsorption in the proximal tubule of rat kidney. Pflügers Arch. Ges. Physiol.360, 183–187 (1975)
Engle, J. E., Steele, T. H.: Renal phosphate reabsorption in the rat: Effect of inhibitors. Kidney Int.8, 98–104 (1975)
Fulop, M., Brazeau, P.: The phosphaturic effect of sodium bicarbonate and acetazolamide in dogs. J. Clin. Invest.47, 983–991 (1968)
Hoffman, N., Thees, M., Kinne, R.: Phosphate transport by isolated renal brush border vesicles. Pflügers Arch. Ges. Physiol.362, 147–156 (1976)
Knox, F. G., Schneider, E. G., Willis, L. R., Strandhoy, J. W., Ott, C. E.: Site and control of phosphate reabsorption by the kidney. Kidney Int.3, 347–353 (1973)
Massry, S. G., Coburn, J. W., Kleeman, C. R.: The influence of extracellular volume expansion on renal phosphate reabsorption in the dog. J. Clin. Invest.48, 1237–1245 (1969)
Mercado, A., Slatopolsky, E., Klahr, S.: On the mechanisms responsible for the phosphaturia of bicarbonate administration. J. Clin. Invest.56, 1386–1395 (1975)
Steele, T. H., DeLuca, H. F.: Influence of the dietary phosphorus on renal phosphate reabsorption in the parathyroidectomized rat. J. Clin. Invest.57, 867–874 (1976)
Steele, T. H.: Renal response to phosphorus deprivation: Effect of the parathyroids and bicarbonate. Kidney Int.11, 327–334 (1977)
Suki, W. N., Martinez-Maldonado, M., Rouse, D., Terry, A.: Effect of expansion of extracellular fluid volume on renal phosphate handling. J. Clin. Invest.48, 1888–1894 (1969)
Tröhler, U., Bonjour, J.-P., Fleisch, H.: Inorganic phosphate homeostasis. Renal adaptation to the dietary intake in intact and thyroparathyroidectomized rats. J. Clin. Invest.57, 264–273 (1976)
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Steele, T.H., Underwood, J.L., Stromberg, B.A. et al. Bicarbonate-induced phosphaturia. Pflugers Arch. 370, 291–294 (1977). https://doi.org/10.1007/BF00585541
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DOI: https://doi.org/10.1007/BF00585541