Toxic effect of cadmium on the primary cultures of rat proximal tubular cells and protective effect of N-acetyl-L-cysteine.

The primary cultures of rat proximal tubular cells were treated with different doses of cadmium acetate and/or N-acetyl-L-cysteine(NAC) to investigate the toxic effect of cadmium on these cells and the protective effect of NAC.Cell survival was detected by using the CCK-8 reduction method and the apoptosis,intracellular reactive oxygen species(ROS) levels and the mitochondrial membrane potential(ΔΨ) were assessed by flow cytometer.After treated with cadmium and/or NAC for 12 hours,the cell survival rates and mitochondrial membrane potential(ΔΨ) in the cadmium exposed groups were significantly lower than those of control group(P0.05 or P0.01).Compared to the control group,the release rate of LDH and the ROS levels in the cadmium groups were significantly increased(P0.05 or P0.01),displaying a dose-dependent manner.Also,a progressive loss in cell viability together with a significant increase in the number of apoptotic and necrotic cells were seen in this experiment,while the cellular death and the apoptosis could be markedly reversed by NAC.In summary,the apoptosis of rat proximal tubular cells may be mediated by oxidative stress,and NAC has a protective effect on the toxic damage induced by cadmium.