Pflügers Archiv

, Volume 408, Issue 4, pp 321–327 | Cite as

d(-)3-Hydroxybutyrate cotransport with Na in rat renal brush border membrane vesicles

  • Mario Barac-Nieto
  • M. McShane
Transport Processes, Metabolism and Endocrinology; Kidney, Gastrointestinal Tract, and Exocrine Glands

Abstract

Which are the driving forces ford(-)3-hydroxybutyrate (HB) transport in rat renal brush border membranes (RBB)? Sodium, even in the absence of gradients, accelerates the unidirectional (1–5 s) flux of HB into rat RBB vesicles. Valinomycin (andKi=Ko) does not significantly alter the NaCl gradient driven HB influx. Thus, the Na-dependent HB influx is driven by the chemical Na+ gradient but it is not driven by changes in the transmembrane electrical potential. Indeed, in valinomycin-treated membranes, vesicle-inside more negative potentials (K-gluconatein-Na-gluconateout) sufficient to accelerate Na-glucose cotransport, did not stimulate HB influx, in the presence of inwardly directed Na+ gradients, and did not significantly inhibit when in the absence of Na+. Thus, cotransport of HB with Na in rat RBB membranes does not involve the net transfer of positive charge and the passive conductance of this membrane for HB is not large. However, vesicle inside more negative potentials (induced by inwardly directed NaNO3 gradients or by outwardly directed K+ gradients and valinomycin in the presence of inwardly directed Na+ gradients) inhibited HB influx, suggesting that another potential sensitive mechanism, perhaps redistribution of intramembrane charges, may influence HB influx. Acidification (pHi=pHo=6.4 vs. 7.4) or inwardly directed H+ gradients (pHo/pHi=6.4/7.4) did not alter HB influx, in the absence of Na+. Thus there is no evidence for a H+ driven HB influx. HB influx is significantly inhibited by high (100 mEq/l) trans concentration of Na+. Also, influx of 2.25 mM14C-HB was significantly increased by 5–10 mM intravesicular HB under Na-equilibrated conditions. Thus, the rate of translocation of the free carrier appears to limit HB influx through the cotransport system.

Key words

Monocarboxylate transport Electrical potential Kinetics 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Barac-Nieto M, Murer H, Kinne R (1980) Lactate-sodium cotransport in rat renal brush border membranes. Am J Physiol 239:F496–F506Google Scholar
  2. 2.
    Barac-Nieto M (1984) Effects of pH, calcium of succinate on sodium citrate cotransport in renal microvilli. Am J Physiol 247:F282–F290Google Scholar
  3. 3.
    Barac-Nieto M (1985) Renal hydroxybutyrate and acetoacetate reabsorption and utilization in the rat. Am J Physiol 249:F40–F48Google Scholar
  4. 4.
    Barac-Nieto M (1986) Renal reabsorption and utilization of hydroxybutyrate and acetoacetate in starved rats. Am J Physiol 251:F257–F265Google Scholar
  5. 5.
    Berner W, Kinne RW (1976) Transport of p-aminohippuric acid by plasma membranes isolated from rat kidney cortex. Pflügers Arch 301:269–277Google Scholar
  6. 6.
    Bradford MM (1976) A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem 72:248–254Google Scholar
  7. 7.
    Evers C, Haas W, Murer H, Kinne R (1978) Properties of brush border vesicles from rat kidney cortex by calcium precipitation. J Membr Biochem 1:203–219Google Scholar
  8. 8.
    Garcia ML, Benavides J, Valdivieso F (1980) Ketone body transport in renal brush border membrane vesicles. Biochim Biophys Acta 600:922–930Google Scholar
  9. 9.
    Guggino SE, Martin GJ, Aronson PS (1983) Specificity and modes of anion exchanger in dog renal microvillus membranes. Am J Physiol 244:F612–F621Google Scholar
  10. 10.
    Jorgenssen KE, Sheikh ML (1985) Mechanisms of uptake of ketone bodies by luminal-membrane vesicles. Biochim Biophys Acta 814:23–34Google Scholar
  11. 11.
    Kessler M, Tannenbaum V, Tannenbaum G (1978) A simple apparatus for performing short-time (1–2 seconds) uptake measurements in small volumes. An application tod-glucose transport studies in brush border vesicles from rabbit jejunum and ileum. Biochim Biophys Acta 509:348–359Google Scholar
  12. 12.
    Kessler M, Semenza G (1983) The small intestinal Na,d-glucose cotransporter: An assymmetric gated channel (or pore) response to Δφ. J Membr Biol 76:27–56Google Scholar
  13. 13.
    Nord SE, Wright SH, Kippen I, Wright EM (1982) Pathways for carboxylic acid transport by rabbit renal brush border membrane vesicles. Am J Physiol 243:F456–F462Google Scholar
  14. 14.
    Nord E, Wright SH, Kippen I, Wright EM (1983) Specificity of the Na-dependent monocarboxylic acid transport pathway in rabbit renal brush border membranes. J Membr Biol 72:213–221Google Scholar
  15. 15.
    Owen O, Licht JH, Sapir DG (1981) Renal function and effects of partial rehydration during diabetic ketoacidosis. Diabetes 30:510–518Google Scholar
  16. 16.
    Reiser S, Christiansen PA (1973) Exchange transport and aminoacid charge as the basis for Na-independent lysine uptake by isolated intestinal epithelial cells. Biochim Biophys Acta 307:223–233Google Scholar
  17. 17.
    Sapir DG, Owen O (1975) Renal conservation of ketone bodies during starvation. Metabolism 24:23–33Google Scholar
  18. 18.
    Snedecor GW, Cochrane WG (1967) Statistical methods, 6th eds. Iowa University Press, AmesGoogle Scholar
  19. 19.
    Turner RJ (1984) Sodium-dependent sulfate transport in renal brush borders. Am J Physiol 247:F793–F798Google Scholar
  20. 20.
    Ullrich KJ, Rumrich G, Kloss S (1982) Reabsorption of monocarboxylic acids in the proximal tubule of the rat kidney. I. Transport kinetics ofd-lactate, Na-dependence, pH-dependence, and effects of inhibitors. Pflügers Arch 395:212–219Google Scholar
  21. 21.
    Ullrich KJ, Rumrich G, Kloss S (1982) Reabsorption of monocarboxylic acids in the proximal tubule of the rat kidney. II. Specificity for aliphatic compounds. Pflügers Arch 395:220–226Google Scholar

Copyright information

© Springer-Verlag 1987

Authors and Affiliations

  • Mario Barac-Nieto
    • 1
  • M. McShane
    • 1
  1. 1.Department of PediatricsAibert Einstein College of MedicineBronxUSA

Personalised recommendations