The Journal of Membrane Biology

, Volume 182, Issue 2, pp 105–112

Changes in Sodium or Glucose Filtration Rate Modulate Expression of Glucose Transporters in Renal Proximal Tubular Cells of Rat

  • S.  Vestri
  • M.M.  Okamoto
  • H.S.  de Freitas
  • R.  Aparecida dos Santos
  • M.T.  Nunes
  • M.  Morimatsu
  • J.C.  Heimann
  • U.F.  Machado

Abstract.

Renal glucose reabsorption is mediated by luminal sodium-glucose cotransporters (SGLTs) and basolateral facilitative glucose transporters (GLUTs). The modulators of these transporters are not known, and their substrates glucose and Na+ are potential candidates. In this study we examined the role of glucose and Na+ filtration rate on gene expression of glucose transporters in renal proximal tubule. SGLT1, SGLT2, GLUT1 and GLUT2 mRNAs were assessed by Northern blotting; and GLUT1 and GLUT2 proteins were assessed by Western blotting. Renal cortex and medulla samples from control rats (C), diabetic rats (D) with glycosuria, and insulin-resistant 15-month old rats (I) without glycosuria; and from normal (NS), low (LS), and high (HS) Na+-diet fed rats were studied. Compared to C and I rats, D rats increased (P < 0.05) gene expression of SGLT2 by ∼36%, SGLT1 by ∼20%, and GLUT2 by ∼100%, and reduced (P < 0.05) gene expression of GLUT1 by more than 50%. Compared to NS rats, HS rats increased (P < 0.05) SGLT2, GLUT2, and GLUT1 expression by ∼100%, with no change in SGLT1 mRNA expression, and LS rats increased (P < 0.05) GLUT1 gene expression by ∼150%, with no changes in other transporters. In summary, the results showed that changes in glucose or Na+ filtrated rate modulate the glucose transporters gene expression in epithelial cells of the renal proximal tubule.

Key words: SGLT2 — SGLT1 — GLUT2 — GLUT1 — Rat kidney 

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Copyright information

© 2001 Springer-Verlag New York Inc.

Authors and Affiliations

  • S.  Vestri
    • 1
  • M.M.  Okamoto
    • 1
  • H.S.  de Freitas
    • 1
  • R.  Aparecida dos Santos
    • 1
  • M.T.  Nunes
    • 1
  • M.  Morimatsu
    • 2
  • J.C.  Heimann
    • 3
  • U.F.  Machado
    • 1
  1. 1.Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, BrazilBR
  2. 2.Department of Biomedical Sciences, School of Veterinary Medicine, Hokkaido University, Sapporo, JapanJP
  3. 3.Department of Nephrology, School of Medicine, São Paulo University, São Paulo, BrazilBR

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