Total Cd accumulation measured by FAAS in CHOCα and wild-type CHO cells. Both cell types were incubated for 1 hour in medium containing 0, 50, or 100 μM Cd and other modifiers. Cd determination was normalized to the cell volume (see text). Treatments were as follows: control 0 Cd (basal), 60 min Cd (Cd), Cd + 30 mM KCl (K), Cd + 30 mM KCl, and 1 μM BayK (B), Cd + 30 mM KCl and 1 μM nimodipine (N). Depolarization (treatment K) did not increase significantly the intracellular concentration of Cd (P > 0.05). In CHOCα cells, but not in wild-type CHO, BayK significantly enhanced and nimodipine significantly reduced Cd accumulation, both with P < 0.001 (*), with respect to the same treatments in depolarization. Bars represent mean ± sem in at least 10 experiments in each group.