Calcium transport in endoplasmic reticulum of the rat liver during lipid peroxidation

Some parameters of calcium transport in rat liver microsomes under conditions of lipoperoxidation activation modelled by antioxidant deficiency (AOD) were studied. This process was shown to be associated with a sharp stimulation of NADPH- and ascorbate-dependent lipid peroxidation in hepatocyte endoplasmic reticulum. The activation of lipid peroxidation was accompanied by disturbances in the kinetic properties of Ca2(+)-ATPase. This was paralleled with a considerable decrease of the ATP-dependent 45Ca-accumulation, increase in the passive permeability of microsomal vesicles for Ca2+ and Ca2+ elevation in the microsomal fraction. The AOD-induced diminution of the Ca2(+)-pump efficiency was slightly prevented by injections of rats with the antioxidants, alpha-tocopherol acetate and ionol which enable Ca2+ compartmentation correction in liver cytosol and membrane fractions.