Cadmium Induced Changes in Metabolic Function of Mitochondrial Isolated from Potato Tissue (Solanum tuberosum L.)

Problem statement: Cadmium is highly toxic at low concentrations, but the mechanism of its toxicity is still not understood particularly at the cellular and subcellular level. Approach: In this study we examined the effects of cadmium on the oxidophosphorylation properties of mitochondria isolated from potatoes. Results: Cadmium strongly disturbed the respiratory metabolism of mitochondria isolated especially in the transfer of electrons by cyanide pathway. Meanwhile, cadmium altered the composition of lipid fatty acids polar while inhibiting catalase activity, a key enzyme in the detoxification (antioxidant) process. In addition, cadmium caused an increase in mitochondrial volume associated with strong inhibition of ATPase activity, which could be explained by a transport of the potassium ion stimulation at the origin of the massive influx of H⁺ by antiport through the K⁺/H⁺ leading to a decoupling (cut) of mitochondrial oxidative phosphorylation. The swelling of mitochondria was accompanied by the rupture of the mitochondrial outer membrane and thus the release of Cytochrome C, which appears to be the initial phase of apoptosis. Conclusion: Following this study, it appeared that cadmium generates in potato the isolated mitochondria a concentration-dependent oxidative stress.