Elsevier

Biochemical Pharmacology

Volume 25, Issue 13, 1 July 1976, Pages 1489-1494
Biochemical Pharmacology

Glucocorticoids—uptake by simple diffusion by cultured reuber and novikoff rat hepatoma cells

https://doi.org/10.1016/0006-2952(76)90066-6Get rights and content

Abstract

The initial rate of uptake of [3H] prednisolonc by cultured NovikolT and Reuber rat hepatoma cells at 18 was directly proportional to the hormone concentration in the medium between 0.01 μm and 5 mM. Uptake of 0.05 μM prednisolone was not affected by 100 μM dexamethasone or deoxycorticosterone or by depletion of the cells of ATP by proincubation in glucose-free medium containing KCN and iodoacetate. Uptake was also not affected by treatment of the cells with neuraminidase or phospholipase C and no countertransport of prednisolone could be demonstrated. Uptake was also unaffected by a 5000-fold excess of d-glucose in the medium, in spite of the fact that prednisolone acts as a simple competitive inhibitor of d-glucosc transport. The results indicate that prednisolone is not taken up by the d-glucosc or some glucocorticoid-specific transport system, but rather enters both types of cells by simple diffusion. Net uptake of prednisolone by the glucocorticoid-unresponsive Novikoff cells ceased when the intracellular concentration was 20–100% higher than that in the medium regardless of the medium concentration, indicating some nonspecific binding of the hormone to cellular components. At a concentration of 0.01 μM in the medium the glucocorticoid-responsive Reuber hcpatoma cells accumulated two to three times more prednisolone/cell than Novikoff cells. This concentrative effect diminished at higher concentrations, indicating saturation of binding sites.

References (37)

  • B. Leboeuf et al.

    J. biol Client.

    (1962)
  • J.N. Fain et al.

    J. biol Client.

    (1963)
  • A. Munck

    J. biol. Chem.

    (1968)
  • J.M. Rosen et al.

    Biochim. biophys. Acta

    (1970)
  • P.G.W. Plagemann et al.

    Biochem. biophys. Res. Commun.

    (1972)
  • J.R. Reel et al.

    J. biol. Chem.

    (1970)
  • F.R. Butcher et al.

    Expl. Cell Res.

    (1971)
  • W.D. Wicks

    J. biol. Chem.

    (1971)
  • C.A. Barnett et al.

    J. biol. Client.

    (1971)
  • M. Beato et al.

    J. biol. Chem.

    (1972)
  • B.W. O'Malley

    Metabolism

    (1971)
  • R.W. Harrison et al.

    Biochem. biophys. Res. Commun.

    (1974)
  • P.G.W. Plagemann et al.

    Biochim. biophys. Acta

    (1974)
  • J. Zylka et al.

    J. biol. Chem.

    (1975)
  • Y.P. See et al.

    Biochim. biophys. Acta

    (1974)
  • H.H. Samuels et al.

    J. molec. Biol.

    (1970)
  • S. Singer et al.

    Biochem. biophys. Res. Commun.

    (1973)
  • J.D. Baxter et al.

    Science. N.Y.

    (1971)
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