Combined Effect of Cadmium and Zinc on Human Embryo Nephridium 293 Cells

[Objective] To examine the dose/time-effect relationship of cytotoxicity of cadmium to human embryo nephridium cell (293 cell) and observe the effect of co-exposure to cadmium and zinc. [Methods] The cell viability was measured by MTT assay, the activity of IDH was measured by colorimetry method and apoptosis of the cells was analyzed by flow cytometry. [Results] Treatment with different levels of CdCl2(20 μmol/L and 40 μmol/L) for 48 h, significantly reduced the viability and heighten the activity of IDH in 293 cells.Treatment with 50 μmol/L ZnCl2 for 12 h not significantly changed the viability and the activity of LDH,and apoptosis of cells could not be induced by ZnCl2 at concentration of 50 μmol/L. Treatment with zinc and cadmium, elevated cell viability and reduced apoptosis and activity of LDH compared with cadmium-exposure cells alone. [Conclusion] The direct toxicity of cadmium to 293 cells is likely related with the membrane damage. Treatment with cadmium induced apoptosis. The change of the indicators mentioned alove depended on time and dose. Zinc may have antagonistic joint action in 293 cells treated with cadmium.