2,5-Di(tert-butyl)-1,4-benzohydroquinone--a novel inhibitor of liver microsomal Ca2+ sequestration

FEBS Lett. 1987 Nov 30;224(2):331-6. doi: 10.1016/0014-5793(87)80479-9.

Abstract

Treatment of rat liver microsomes with 2,5-di(tert-butyl)-1,4-benzohydroquinone caused a dose-related inhibition (Ki congruent to 1 microM) of ATP-dependent Ca2+ sequestration. This was paralleled by a similar impairment of the microsomal Ca2+-stimulated ATPase activity. In contrast, the hydroquinose failed to induce Ca2+ release from Ca2+-loaded liver mitochondria (supplied with ATP), and inhibited neither the mitochondrial F1F0-ATPase nor the Ca2+-stimulated ATPase activity of the hepatic plasma membrane fraction. The inhibition of microsomal Ca2+ sequestration was not associated with any apparent alteration of membrane permeability or loss of other microsomal enzyme activities or modification of microsomal protein thiols. These findings suggest that 2,5-di(tert-butyl)-1,4-benzohydroquinone is a potent and selective inhibitor of liver microsomal Ca2+ sequestration which may be a useful tool in studies of Ca2+ fluxes in intact cells and tissues.

MeSH terms

  • Animals
  • Calcium / metabolism*
  • Calcium-Transporting ATPases / metabolism*
  • Cell Compartmentation / drug effects
  • Cell Membrane / enzymology
  • Cytochrome P-450 Enzyme System / metabolism
  • Hydroquinones / pharmacology*
  • In Vitro Techniques
  • Male
  • Microsomes, Liver / drug effects*
  • Microsomes, Liver / metabolism
  • Mitochondria, Liver / metabolism
  • Rats

Substances

  • Hydroquinones
  • 2,5-di-tert-butylhydroquinone
  • Cytochrome P-450 Enzyme System
  • Calcium-Transporting ATPases
  • Calcium