Abstract: Objective To study the damage effects of different doses ofcadmium (Cd²⁺) on human normal liver cell line HL-7702 cells and its mechanism. Methods HL-7702 cell cultures were exposed to cadmium within a dose range of 5-40 μmol·L^-1. The inhibition of the cells during 8 d was determined by cell counting and the cell growth curve was made. The cytotoxicity of cells during 72 h was determined by MTT assay. Effects of cadmium on the distribution of cell cycle of HL-7702 cells were monitored by flow cytometry analysis (FCM). The apoptotic rate of cells induced by cadmium was determined by Annexin V-FITC/PI double fluorescent staining flow cytometry analysis(FCM) at the same time. Results Cadmium at different concentrations inhibited the growth and proliferation of HL-7702 cells in a dose-dependent manner and the cell growth curve changed accordingly. After treated by different concentrations of cadmium for 24,48 and 72 h, the cell inhibitory rates increased with the elevating of doses. After 48 and 72 h exposure of cadmium, the data showed that certain doses of cadmium might induce S blocking, and this effect was in time- and dose-dependent manner. After 24,48 and 72 h exposure of cadmium，the data suggested that certain doses of cadmium might induce apoptosis. Conclusion Cadmium can significantly inhibit the growth and proliferation of HL-7702 cells and result in S blocking and apoptosis may be responsible for the inhibition.

Key words: hepatocytes, cell cycle, apoptosis