The mechanism of decreased Na+-dependent D-glucose transport in brush-border membrane vesicles from rabbit kidneys with experimental Fanconi syndrome.

Abstract

In our previous paper (Yanase, M. et al. (1983) Biochim. Biophys. Acta 733, 95-101) we reported that the Na+-dependent D-glucose uptake into brush-border membrane vesicles is decreased in rabbits with experimental Fanconi syndrome (induced by anhydro-4-epitetracycline). In the present paper we investigate the mechanism underlying this decrease. D-Glucose is taken up into the osmotically active space in anhydro-4-epitetracycline-treated brush-border membrane vesicles and exhibits the same distribution volume and the same degree of nonspecific binding and trapping as in control brush-border membrane vesicles. The passive permeability properties of control and anhydro-4-epitetracycline-treated brush-border membrane vesicles are shown to be the same as measured by the time-dependence of L-glucose efflux from brush-border membrane vesicles. D-Glucose flux was measured by the equilibrium exchange procedure at constant external and internal Na+ concentrations and zero potential. Kinetic analyses of Na+-dependent D-glucose flux indicate that Vmax in anhydro-4-epitetracycline-treated brush-border membrane vesicles (79.3 +/- 7.6 nmol/min per mg protein) is significantly smaller than in control brush-border membrane vesicles (141.3 +/- 9.9 nmol/min per mg protein), while the Km values in the two cases are not different from each other (22.3 +/- 0.9 and 27.4 +/- 1.8 mM, respectively). These results suggest that Na+-dependent D-glucose carriers per se are affected by anhydro-4-epitetracycline, and that this disorder is an important underlying mechanism in the decreased Na+-dependent D-glucose uptake into anhydro-4-epitetracycline-treated brush-border membrane vesicles.

• Authors: Y Orita, Y Fukuhara, M Yanase, N Okada, T Nakanishi, M Horio, T Moriyama, A Ando, H Abe
• Journal: Biochimica et biophysica acta (Biochim Biophys Acta) Vol. 771 Issue 2 Pg. 195-200 (Apr 11 1984) ISSN: 0006-3002 [Print] Netherlands
• PMID: 6538438 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Carrier Proteins
• Monosaccharide Transport Proteins
• Sodium
• Glucose

Topics

• Animals
• Carrier Proteins (metabolism)
• Cell Membrane Permeability (drug effects)
• Disease Models, Animal
• Fanconi Syndrome (metabolism)
• Glucose (metabolism)
• Kidney (metabolism)
• Kinetics
• Microvilli (metabolism)
• Monosaccharide Transport Proteins
• Osmolar Concentration
• Rabbits
• Sodium (pharmacology)