Advertisement

Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Microperfusion study of the kinetics of reabsorption of cycloleucine in early and late segments of the proximal convolution of the rat nephron

Summary

The proximal tubular reabsorptive capacity for the non-metabolizable amino acid, cycloleucine, was studied in the rat nephron by stationary microperfusion. Tubular reabsorptive rates were greatest near the glomerulus and declined progressively along the convolution. A kinetic analysis of cycloleucine reabsorption in terms of luminal concentration revealed that this reduced transport rate was associated with an increase in the half-saturation constant of the kinetic curve, rather than a decrease in the maximum transport capacity. Since our previous findings with the metabolizable amino acid,l-histidine, were identical we can conclude that this decline in reabsorption of neutral amino acids as a function of distance along the convolution is an intrinsic property of the transport system and is not related to tubule cell amino acid metabolism.

The transport curves for cycloleucine absorption did not give a simple Michaelis-Menten relation but rather followed a course suggesting that more than one transport system might be involved.

This is a preview of subscription content, log in to check access.

References

  1. 1.

    Bode, F., Chan, Y. L., Goldner, A. M., Papavassiliou, F., Wagner, M., Baumann, K.: Reabsorption ofd-glucose from various regions of the rat proximal convoluted tubule: evidence that the proximal convolution is not homogeneous. In: Symposium on Biochemical Aspects, of Renal Function, Gdansk, September 1973 (in press, 1975)

  2. 2.

    Botts, J.: Typical behaviour of some simple models of enzyme action. Trans. Faraday Soc.54, 593–604 (1958)

  3. 3.

    Christensen, H. N., Clifford, J. A.: Excretion of 1-aminocyclopentane carboxylic acid in man and the rat. Biochim. biophys. Acta (Amst.)62, 160–162 (1962)

  4. 4.

    Christensen, H. N., Jones, J. C.: Amino acid transport models: renal resorption and resistance to metabolic attack. J. biol. Chem.237, 1203–1206 (1962)

  5. 5.

    Eisenbach, G. M., Weise, M., Stolte, H.: Amino acid reabsorption in the rat nephron. Pflügers Arch. (in press, 1975)

  6. 6.

    Frömter, E., Geßner, K.: Active transport potentials, membrane diffusion potentials and streaming potentials across rat kidney proximal, tubules. Pflügers Arch.351, 85–98 (1974)

  7. 7.

    Frömter, E., Rumrich, G., Ullrich, K. J.: Phenomenologic description of Na+, Cl and HCO 3 absorption from proximal tubules of the rat kidney. Pflügers Arch.343, 189–220 (1973)

  8. 8.

    Goyer, R. A., Reynolds, J. O., Elston, R. C.: Characteristics of the aminoaciduria resulting from cycloleucine administration in pair-fed rats. Proc. Soc. exp. Biol. (N. Y.)130, 860–863 (1969)

  9. 9.

    Györy, A. Z., Lingard, J. M., Young, J. A.: Relation between active sodium transport and distance along the proximal convolutions of rat nephrons: evidence for homogeneity of sodium transport. Pflügers Arch.348, 205–210 (1974)

  10. 10.

    Györy, A. Z., Lingard, J. M., Young, J. A.: Proximal tubular inhomogeneity for neutral amino acids in the rat kidney. J. Physiol. (Lond.)241, P126-P127 (1974)

  11. 11.

    Le Grimellec, C.: Micropuncture study along the proximal convoluted tubule. Pflügers Arch.354, 133–150 (1975)

  12. 12.

    Lingard, J. M., Györy, A. Z., Young, J. A.: Analysis of the reabsorptive characteristics of neutral amino acids in the proximal convolution of the rat kidney. Proc. Aust. Physiol. Pharmacol. Soc.5, 223–225 (1974)

  13. 13.

    Lingard, J., Rumrich, G., Young, J. A.: Reabsorption ofl-glutamine andl-histidine from various regions of the rat proximal convolution studied by stationary microperfusion: Evidence that the proximal convolution is not homogeneous. Pflügers Arch.342, 1–12 (1973)

  14. 14.

    Lingard, J., Rumrich, G., Young, J. A.: Kinetics ofl-histidine transport in the proximal convolution of the rat, nephron studied using the stationary microperfusion technique. Pflügers Arch.342, 13–28 (1973)

  15. 15.

    Meister, A.: Biochemistry of the amino acids, Vol. 1, pp. 27–31. New York-London: Academic Press 1965

  16. 16.

    Oxender, D. L., Christensen, H. N.: Distinct mediating systems for the transport of neutral amino acids by the Ehrlich cell. J. biol. Chem.238, 3686–3699 (1963)

  17. 17.

    Silbernagl, S.: Cycloleucine (1-aminocyclopentane carboxylic acid): Tubular reabsorption and inhibitory effect on amino acid transport in the rat kidney. Pflügers Arch.353, 241–253 (1975)

  18. 18.

    Silbernagl, S., Deetjen, P.: Arginine transport in rat proximal tubules. Microperfusion studies on reabsorption kinetics. Pflügers Arch.336, 79–86 (1972)

  19. 19.

    Staum, B. B., Hamburger, R. J., Goldberg, M.: Tracer microinjection study of renal tubular phosphate reabsorption in the rat. J. clin. Invest.51, 2271–2276 (1972)

  20. 20.

    Ullrich, K. J., Sauer, F.: Permeability characteristics of the mammalian nephron. Nonequilibrium thermodynamics of kidney tubule transport. In: Handbook of physiology, Section 8, pp. 377–414. J. Orloff and R. W., Berliner, eds. Washington: American Physiological Society 1973

  21. 21.

    Young, J. A., Freedman, B. S.: Renal tubular transport of amino acids. Clin. Chem.17, 245–266 (1971)

Download references

Author information

Additional information

Preliminary reports of this work have already been published [10, 12]. The project was supported by the National Health and Medical Research Council of Australia, The Australian Kidney Foundation, and the Post-Graduate Medical Foundation of the University of Sydney. One of us (J.M.L.) was the recipient of an Australian Government Post-Graduate Studentship.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Lingard, J.M., Györy, A.Z. & Young, J.A. Microperfusion study of the kinetics of reabsorption of cycloleucine in early and late segments of the proximal convolution of the rat nephron. Pflugers Arch. 357, 51–61 (1975). https://doi.org/10.1007/BF00584544

Download citation

Key words

  • Cycloleucine
  • Transport Kinetics
  • Kidney Tubule
  • Amino Acid Transport
  • Microperfusion