FIGURE 1.

MT expression is induced by metals. A, dose-dependent induction of MT expression by metals. HEK cells were treated with CdCl₂, ZnSO₄, CuSO₄, PbAc, NiSO₄, NaAsO₂, and K₂Cr₂O₇ at the concentrations indicated for 12 h and followed by immunoblotting analysis with an antibody against MT. Cytotoxicity was measured by using MTT assay at the indicated concentrations. The relative cell viability corresponding to the amount of MT is calculated as the ratio of each dose of a particular metal to that observed in control cells treated with a vehicle and is indicated under each lane. B, time-dependent induction of MT proteins. HEK cells were treated with metals at the indicated concentrations for 2, 6, 12, or 24 h, and the cell lysates isolated at each time point were subjected to immunoblotting analysis using the antibodies indicated.