The alterations in the energy linked properties induced in rat liver mitochondria by acetylsalycilate are prevented by cyclosporin A or Mg2

Abstract The alterations in rat liver mitochondria induced by acetylsalicylate in the presence of low concentrations of Ca 2+ (large amplitude swelling, permeability to [ 14 C]sucrose, collapse of transmembrane potential and effluxes of endogenous Mg 2+ and accumulated Ca 2+ ) were fully prevented by either cyclosporin A or Mg 2+ . Cyclosporin A and Mg 2+ were also capable of restoring transmembrane potential upon its decrease induced by acetylsalicylate. The loss of endogenous Mg 2+ was the primary effect promoted by acetylsalicylate; the other noxious effects followed. These results indicate that Mg 2+ are fundamental components of the mitochondrial permeability barrier and that their loss might be responsible for the membrane transition induced by acetylsalicylate.