Na-dependent D-glucose transport by intestinal brush border membrane vesicles from gilthead sea bream (Sparus aurata)

M. Sala-Rabanal, M. A. Gallardo, J. Sánchez, J. M. Planas

Research output: Contribution to journalArticlepeer-review

30 Scopus citations

Abstract

Brush border membrane vesicles (BBMV) enriched in sucrase, maltase and alkaline phosphatase, and impoverished in Na+-K+-ATPase, were isolated from proximal and distal intestine of the gilthead sea bream (Sparus aurata) by a MgCl2 precipitation method. Vesicles were suitable for the study of the characteristics of D-glucose apical transport. Only one D-glucose carrier was found in vesicles from each intestinal segment. In both cases, the D-glucose transport system was sodium-dependent, phlorizin-sensitive, significantly inhibited by D-glucose, D-galactose, α-methyl-D-glucose, 3-O-methyl-D-glucose and 2-deoxy-D-glucose, and showed stereospecificity. Apparent affinity constants of D-glucose transport (K t) were 0.24 ± 0.03 mM in proximal and 0.18 ± 0.03 mM in distal intestine. Maximal rate of influx (Jmax) was 47.3 ± 2.2 pmols. mg-1 protein for proximal and 27.3 ± 3.6 pmols. mg -1 protein for distal intestine. Specific phlorizin binding and relative abundance of an anti-SGLT1 reactive protein were significantly higher in proximal than in distal BBMV. These results suggest the presence of the same D-glucose transporter along the intestine, with a higher density in the proximal portion. This transporter is compatible with the sodium-dependent D-glucose carrier described for other fish and with the SGLT1 of higher vertebrates.

Original languageEnglish
Pages (from-to)85-96
Number of pages12
JournalJournal of Membrane Biology
Volume201
Issue number2
DOIs
StatePublished - Nov 1 2004

Keywords

  • Brush border membrane vesicles
  • Distal intestine
  • Fish
  • Freezing
  • Proximal intestine
  • SGLT1

Fingerprint

Dive into the research topics of 'Na-dependent D-glucose transport by intestinal brush border membrane vesicles from gilthead sea bream (Sparus aurata)'. Together they form a unique fingerprint.

Cite this