The effect of metal ions on free radical formation in lung and brain of rats

The influence of 14 metal ions on free radical (FR) formation in subcellular systems of lung mitochondria and brain synaptosomes (cortex and cerebellum) of rats was investigated. Iron and manganese showed a highly significant increase in FR formation in lung, whereas other investigated metal ions showed relatively slight, insignificant decreases in FR. The significant enhancement effects of iron and manganese increased with their content in the media. Scandium exhibited an insignificant enhancement effect at a low concentration of 0.01 microM, but also an insignificant decrease in FR formation in lung at higher concentrations. In brain cerebellum only iron significantly increased FR formation but manganese, as well as trivalent metals (Al, La, Sc), showed insignificant changes in FR formation. The possible causes of differences induced by metal ions at various concentrations, as well as the biological functions of the investigated tissues, were considered in the explanation of obtained results.