Figure 9.

Arsenite treatment induces the use of selenium derived from serum but not from l-selenocysteine (SeCys). HaCat cells were cultivated in DKM as in Figure 5. Where indicated, FBS was added to 10%, or l-selenocystine was added to give 50 nM. Arsenite was added at the concentrations indicated below the autoradiogram, and cells were allowed to grow for 24 hr, as in the previous experiments shown in Figures 2 and 5.