Copper(II) and iron(III) ions inhibit respiration and increase free radical-mediated phospholipid peroxidation in rat liver mitochondria: Effect of antioxidants.

Copper(II) and iron(III) ions inhibit respiration and increase free radical-mediated phospholipid peroxidation in rat liver mitochondria: Effect of antioxidants. J Inorg Biochem. 2017 Apr 19;172:94-99 Authors: Saporito-Magriñá C, Musacco-Sebio R, Acosta JM, Bajicoff S, Paredes-Fleitas P, Reynoso S, Boveris A, Repetto MG Abstract Rat liver mitochondria (1.5-2.1mg protein·mL(-1)) supplemented with either 25 and 100μM Cu(2+) or 100 and 500μM Fe(3+) show inhibition of active respiration (O2 consumption in state 3) and increased phospholipid peroxidation . Liver mitochondria were supplemented with the antioxidants reduced glutathione, N-acetylcysteine or butylated hydroxitoluene, to evaluate their effects on the above-mentioned alterations. Although the mitochondrial dysfunction is clearly associated to phospholipid peroxidation, the different responses to antioxidant supplementation indicate that the metal ions have differences in their mechanisms of toxicity. Mitochondrial phospholipid peroxidation through the formation of hydroxyl radical by a Fenton/Haber-Weiss mechanism seems to precede the respiratory inhibition and to be the main fact in Fe-induced mitochondrial dysfunction. In the case of Cu(2+), it seems that the ion oxidizes glutathione, and low molecular weight protein thiol groups in a direct reaction, as part of its intracellular redox cycling. The processes involving phospholipid peroxidation, protein oxidation and mito...
Source: Journal of Inorganic Biochemistry - Category: Biochemistry Authors: Tags: J Inorg Biochem Source Type: research