Cadmium chloride generates cytotoxic reactive species that cause oxidative damage and morphological changes in human...

Cadmium chloride (CdCl₂₎ is a widely used industrial compound that exhibits multiple organ toxicity. Cadmium is transported through blood where erythrocytes are exposed to its action. Here the effect of CdCl₂ on human erythrocytes was examined under in vitro conditions. Human erythrocytes were treated with 0.01-0.5 mM CdCl₂ for 24 h at 37 °C. Lysates were made from CdCl₂ treated and untreated (control) cells and used for further analysis. CdCl₂ treatment resulted in marked hemolysis of erythrocytes and oxidation of hemoglobin to methemoglobin. This will result in anemia and also reduce the oxygen carrying ability of erythrocytes. Hemoglobin oxidation was accompanied by degradation of heme and release of free ferrous iron moiety. Further analysis showed elevated lipid hydroperoxides and formation of advanced oxidation protein products along with reduction in total sulfhydryl content, indicating the generation of oxidative stress condition in the cell. Incubation of erythrocytes with CdCl₂ enhanced generation of reactive oxygen and nitrogen species, decreased the antioxidant power and inhibited pathways of glucose metabolism. Plasma membrane was damaged as indicated by enhanced osmotic fragility and inhibition of membrane bound enzymes. This was confirmed by electron microscopy which showed formation of echinocytes. These results show that CdCl₂ generates reactive species which impair the antioxidant system resulting in oxidative damage to erythrocytes.