Oxidative damage induced by metals wihout redox capacity in biological systems

ABSTRACT

Results of our studies on several metals that have no redox capacity in biological systems, but can promete reactive oxygen species (ROS)-mediated reactions in in vivo and in vitro systems, will be presented. The experimental evidence indicates that the prooxidant effect of Al, Sc, Ga, In, Y, Be, La and Pb could be in part due to the interaction of metals with membranes, leading to changes in membrane physical properties, which include increase in lipid packing or lipid phase separation that can facilitate the initiation or propagation of lipid peroxidation in the presence of an initiator. The consequent relesse to the media of lipid peroxidation products could secondarily cause oxidative modifications of proteins and DNA. In vivo, Zn deficiency causes oxidative damage to lipids, proteins and DNA. This could be due to a decrease in the antioxidant actions of Zn per se or to the increase in iron tissue levels which occurs secondarily to Zn-deficiency.