Attenuation of hypermetabolism in the remnant kidney by dietary phosphate restriction in the rat
| Autor: | Robert W. Schrier, D. C. H. Harris, L. Chan, Joseph I. Shapiro |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Male
medicine.medical_specialty Magnetic Resonance Spectroscopy Physiology medicine.drug_class Intracellular pH Glycine Kidney Nephrectomy Phosphates chemistry.chemical_compound Oxygen Consumption Reference Values Internal medicine medicine Animals Renal sodium reabsorption Osmolar Concentration Kidney metabolism Rats Inbred Strains Phosphate Phosphate binder Diet Rats Endocrinology medicine.anatomical_structure chemistry Renal physiology Hypermetabolism |
| Zdroj: | The American journal of physiology. 258(1 Pt 2) |
| ISSN: | 0002-9513 |
| Popis: | In vivo energy metabolism in remnant and normal kidney nephrons and the effect of dietary phosphate restriction on energy metabolism were studied. Tissue concentrations of ATP did not differ between remnant and normal kidneys; however, the tissue concentration of inorganic phosphate (Pi) was higher in remnant kidneys (1.17 +/- 0.10 vs. 0.82 +/- 0.09 mumol/g, P less than 0.05) as assessed by 31P-nuclear magnetic resonance (NMR). Intracellular pH was also higher in remnant kidneys (7.48 +/- 0.04 vs. 7.20 +/- 0.05, P less than 0.01), as was oxygen consumption (QO2) when normalized for rate of net tubular sodium reabsorption (Tna; 0.032 +/- 0.005 vs. 0.018 +/- 0.002 mumol.min-1.g-1, P less than 0.01). Compared with glycine supplemented controls, dietary phosphate restriction induced by the phosphate binder diaminodihydroacetoacetate, a maneuver which independently of protein restriction has been shown to ameliorate the progression of chronic renal failure, resulted in no major change in tissue levels of ATP, intracellular pH, or TNa+ but decreased Pi (0.62 +/- 0.07 vs. 1.40 +/- 0.11 mumol/g, P less than 0.01) and QO2 (4.0 +/- 0.4 vs. 7.7 +/- 1.0 mumol.min-1.g-1, P less than 0.01) in remnant kidneys. For the amount of sodium reabsorption performed, remnant kidneys are hypermetabolic, and this hypermetabolism is attenuated by dietary phosphate restriction. These data suggest that hypermetabolism may be involved in the tubulointerstitial mechanisms operant in the progression of chronic renal failure that occurs in the rat remnant kidney, and that attenuation of this abnormality may be the mechanism by which dietary phosphate restriction ameliorates this process. |
| Databáze: | OpenAIRE |
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