Effect of cadmium and colcemide on the mitoses of a human epithelial cell line with high content of cytoplasmic metallothionein.

Cultures of cell strains with and without metallothionein were exposed to CdCl2 in doses ranging from 10 mu mol/l to 200 mu mol/l . Cell growth parameters were monitored by flow cytometric DNA-measurements, cell counts and counting of mitoses during the first two days after exposure. CdCl2 inhibited cell growth in a dose dependent way. The cadmium resistant cells were inhibited with concentrations above 100 mu mol/l, the concentration which the metallothionein-containing cells had previously been adjusted to. Microscopy of the cell cultures showed a dose dependent accumulation of cells in the mitotic prophase, whereas the other phases of the cell cycle were unaffected as measured by flow cytometry. When exposed to colcemide, however, the two cell strains showed identical responsiveness.