Ca2+-loading modulates potencies of cyclosporin A, Mg2+ and ADP to recouple permeabilized rat liver mitochondria Academic Article uri icon

Overview

MeSH Major

  • Adenosine Diphosphate
  • Cyclosporine
  • Magnesium Sulfate
  • Mitochondria, Liver

abstract

  • We studied the relative potencies of cyclosporin A and endogenous effectors (Mg2+ and ADP) to recouple rat liver mitochondria permeabilized by different Ca(2+)-loading in a P(i)-containing medium. Recoupling efficiency of cyclosporin A dramatically decreased at high Ca(2+)-loading (approx. 100 nM of Ca2+/mg protein and more). Mitochondria permeabilized by high Ca2+ were recoupled with approximately equal efficiency by higher cyclosporin A concentrations or by adding 1-5 mM Mg2+ together with low concentrations of cyclosporin A while potentiating effect of ADP on the cyclosporin A recoupling potency was insignificant. Mg2+ ions at concentrations of 3 mM and higher also prevented the carboxyatractylate-induced reversion of cyclosporin A recoupling effect. The data point to competitive relationships between cyclosporin A and/or Mg2+ ions and Ca2+ ions for the site(s) regulating permeability state of the pore.

publication date

  • January 1994

Research

keywords

  • Academic Article

Identity

Language

  • eng

PubMed ID

  • 7849648

Additional Document Info

start page

  • 367

end page

  • 73

volume

  • 34

number

  • 2