Elsevier

Life Sciences

Volume 62, Issue 23, 1 May 1998, Pages 2109-2126
Life Sciences

Biosynthesis of digitalis-like compounds in rat adrenal cells: Hydroxycholesterol as possible precursor

https://doi.org/10.1016/S0024-3205(98)00186-6Get rights and content

Abstract

The biosynthesis of digitalis-like compounds (DLC) was determined in bovine and rat adrenal homogenates, as well as in primary rat adrenal cells, by following changes in the concentration of DLC using three independent sensitive bioassays: inhibition of [3H]-ouabain binding to red blood cells and competitive ouabain and bufalin ELISA. The amounts of DLC in bovine and rat adrenal homogenates, as measured by the two first bioassays, increased with time when the mixtures were incubated under tissue culture conditions. Rat primary adrenal cells were incubated in the presence of [1,2-3H]-25-hydroxycholesterol, [26,27-3H]-25-hydroxycholesterol or [7-3H]-pregnenolone. The radioactive products, as well as the digitalis-like activity, were fractionated by three sequential chromatography systems. When [1,2-3H]-25-hydroxycholesterol or [7-3H]-pregnenolone was added to the culture medium, the radioactivity was co-eluted with digitalis-like activity, suggesting that at least one of the DLC might originate in hydroxycholesterol. In contrast, when the culture medium was supplemented with [26,27-3H]-25-hydroxycholesterol, the radioactivity was not co-eluted with the digitalis-like activity, indicating that side chain cleavage is the first step in the synthesis of digitalis-like compounds by rat adrenal.

References (29)

  • A. Goto et al.

    Biochem. Biophys. Res. Commun.

    (1990)
  • M. Tamura et al.

    J. Biol. Chem.

    (1994)
  • A.L. Rauch et al.

    Biochem. Biophys. Res. Commun.

    (1988)
  • J. Laredo et al.

    Biochim. Biophys. Res. Commun.

    (1995)
  • N.B. Goldring et al.

    J. Biol. Chem.

    (1985)
  • F. Masugi et al.

    Biochem. Biophys. Res. Comm.

    (1986)
  • D.E. Gartner et al.

    FEBS Lett.

    (1990)
  • M.D. Siperstein et al.

    Arch. Biochem. Biophys.

    (1957)
  • A.M. Porto et al.

    J. Steroid Biochem.

    (1972)
  • D. Lichtstein et al.

    J. Basic Clin. Physiol. Pharmacol.

    (1992)
  • R.G. Wolfson et al.

    Kidney Int.

    (1994)
  • J.M. Hamlyn et al.
  • A.A. Tymiak et al.
  • D. Lichtstein et al.

    Eur. J. Biochem.

    (1993)
  • Cited by (0)

    View full text