The Journal of Membrane Biology

, Volume 82, Issue 1, pp 59–65 | Cite as

Hexose regulation of sodium-hexose transport in LLC-PK1 epithelia: The nature of the signal

  • A. Moran
  • R. J. Turner
  • J. S. Handler


We have shown previously that the concentration of glucose in the growth medium regulates sodium-coupled hexose transport in epithelia formed by the porcine renal cell line LLC-PK1. Assayed in physiological salt solution, the ratio of the concentration of α-methyl glucoside (AMG) accumulated inside the cell at steady state to its concentration outside, and the number of glucose transporters, as measured by phlorizin binding, was inversely related to the glucose concentration in the growth medium. In this study, using a cloned line of LLC-PK1 cells, we provide evidence that the difference in AMG concentrating capacity is the result of a regulatory signal and not simply due to a selection process where the growth of cells with enhanced glucose transport is favored by low glucose medium or vice-versa. By adding glucose to conditioned medium (collected after 48 hr incubation with cells and therefore containing less than 0.1mm glucose), we demonstrate that the signal in the growth medium is indeed the concentration of glucose rather than another factor secreted into or depleted from the medium. Fructose and mannose, two sugars not transported by the sodium-dependent glucose transporter, can substitute for glucose as a carbohydrate source in the growth medium and have a modest glucose-like effect on the transporter. Growth in medium containing AMG does not affect the transporter, indicating that the regulatory signal is not a direct effect of the hexose on its carrier but involves hexose metabolism.

Key Words

cultured epithelia hexose transport transport regulation 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Amsler, K., Cook, J.S. 1982. Development of Na+ dependent hexose transport in a culture line of porcine kidney cells.Am. J. Physiol. 242:C94-C101PubMedGoogle Scholar
  2. 2.
    Bader, J.P., Brown, N.R., Ray, D.A. 1981. Increased glucose uptake capacity of Rous-transformed cells and the relevance of deprivation depression.Cancer Res. 41:1702–1709PubMedGoogle Scholar
  3. 3.
    Burton, M.W., Reitzer, L.J., Kennell, D. 1981. The continuous growth of vertebrate cells in the absence of sugars.J. Biol. Chem. 256:7812–7819PubMedGoogle Scholar
  4. 4.
    Cook, J.S., Amsler, K., Weiss, E.R., Shaffer, C. 1982. Development of Na+ hexose transportin vitro.In: Membranes in Growth and Development. J.F. Hoffman, G. Giebisch, and L. Bolix, editors. pp. 551–567. A.R. Liss, New YorkGoogle Scholar
  5. 5.
    Hull, R.N., Cherry, W.R., Weaver, G.W. 1976. The origin and characteristics of a pig kidney cell strain LLC-PK1.In Vitro 12:670–677PubMedGoogle Scholar
  6. 6.
    Mills, J.W., Macknight, A.D.C., Jarrell, J.A., Dayer, J.M., Ausiello, D.A. 1981. Interaction of ouabain with the Na+ pump in intact epithelial cells.J. Cell Biol. 88:637–643PubMedGoogle Scholar
  7. 7.
    Misfeldt, D.S., Sanders, M.J. 1983. Transepithelial transport in cell culture:d-glucose transport by a pig kidney cell line (LLC-PK1).J. Membrane Biol. 59:13–18Google Scholar
  8. 8.
    Misfeldt, D.S., Sanders, M.J. 1983. Transepithelial transport in cell culture: Stoichiometry of Na/phlorizin binding and Na/d-glucose cotransport. A two-step, two-sodium model of binding and translocation.J. Membrane Biol. 70:191–198Google Scholar
  9. 9.
    Moran, A., Handler, J.S., Turner, R.J. 1982. Na+ dependent hexose transport in vesicles from cultured renal epithelial cell line.Am. J. Physiol. 243:C293-C298PubMedGoogle Scholar
  10. 10.
    Moran, A., Turner, R.J., Handler, J.S. 1983. Regulation of sodium coupled glucose transport by glucose in a cultured epithelium.J. Biol. Chem. 258:15087–15090PubMedGoogle Scholar
  11. 11.
    Mullin, J.M., Weilbel, J., Diamond, L., Kleinzeller, A. 1980. Sugar transport in the LLC-PK1 renal epithelial cell line: Similarity to mammalian kidney and the influence of cell density.J. Cell Physiol. 104:375–389PubMedGoogle Scholar
  12. 12.
    Rabito, C.A. 1980. Phosphate transport by a kidney epithelial cell line.J. Gen. Physiol. 76:20a Google Scholar
  13. 13.
    Rabito, C.A. 1981. Localization of the Na+ sugar cotransport system in a kidney epithelial cell line (LLC-PK1).Biochim. Biophys. Acta. 649:286–297PubMedGoogle Scholar
  14. 14.
    Rabito, C.A., Karish, M.V. 1982. Polarized amino acid transport by an epithelial cell line of renal origin (LLC-PK1). The basolateral system.J. Biol. Chem. 257:6802–6808PubMedGoogle Scholar
  15. 15.
    Sanders, M.J., Simon, L.M., Misfeldt, D.S. 1982. Transepithelial transport in cell culture: Bioenergetics of Na,d-glucose coupled transport.J. Cell Physiol. 114:263–266Google Scholar
  16. 16.
    Turner, R.J., Moran, A. 1982. Heterogeneity of sodium dependentd-glucose transport sites along the proximal tubule.Am. J. Physiol. 242:F406-F414PubMedGoogle Scholar
  17. 17.
    Turner, R.J., Moran, A. 1982. Further studies of proximal tubular brush border membraned-glucose transport heterogeneity.J. Membrane Biol. 70:37–45Google Scholar
  18. 18.
    Ullrey, D., Gammon, M.T., Kalckar, H.M. 1975. Uptake patterns and transport enhancements in cultures of hamster cells deprived of carbohydrates.Arch. Biochem. Biophys. 167:410–416PubMedGoogle Scholar

Copyright information

© Springer-Verlag 1984

Authors and Affiliations

  • A. Moran
    • 1
  • R. J. Turner
    • 2
  • J. S. Handler
    • 2
  1. 1.Physiology DepartmentArmed Forces Radiobiology Research InstituteBethesda
  2. 2.National Heart, Lung and Blood InstituteNational Institutes of HealthBethesda

Personalised recommendations