Oxidative Damage Mechanism Of Low Dose Of Cadmium To Yeast Cells

Oxidative Damage Mechanism of Low Dose of Cadmium to Yeast CellsCadmium is a kind of poisonous heavy metals, which lead to a serious poisoned accident in Japan last 60s. From then on, many scientists were attracted to investigate the cadmium's toxicology. Low dose of cadmium has serious toxicity to organism. But its accurate action-map and which cellular organ is its target are unsolved yet. In order to resolve the problem, we design a series experiments.Saccharomyces cerevisiae is a good model organism. Through investigating cadmium effects on S. cerevisiae, we can get known cadmium action mechanism to other eukaryotes.Mitochondria are the power center of eukaryotic cell, which affect many aspects of cellular actions. What more, mitochondria are the major locus of generating free radical oxygen. 2% of oxygen is transformed into free radical oxygen in cellular metabolism, so the sum of free radical oxygen in cell is concerned with mitochondria's condition. Cadmium has been experimental proved able to induce oxidative stress in yeast. How it happened is unknown. In my experiments, I control the metabolism state of mitochondria through changing the volume of glucose in medium, and then detect the level of mitochondria DNA being oxidized in different metabolism states. Finally, Conclusion is made by analyzing the experimental data.After exposed to CdCI₂ dosed 10μmol/L for 10 hours, yeast cells were collected for survival assay and oxidative damage of mitochondria DNA was assessed through detecting the level of 8-OH-dG/10⁵dG by HPLC-EC. All the results were compared between the situations with or without glucose in medium. It was concluded that Cd²⁺ tolerance of the yeast was higher in glucose-free medium than that in glucose-sufficient medium (P <0.01) and the yeast in glucose-free medium had a low level of oxidative damage in mitochondrial DNA (P <0.01).