A tissue culture model for mercury-selenium interactions

In five- and six-day growth studies, Chang's liver cells and 3T3 cells were protected against selenite toxicity by mercuric chloride and by monomethyl mercury. They were also protected against mercuric chloride toxicity by selenite. The following results were obtained with Chang's liver cells only: Methyl mercury inhibits selenite uptake, and the optimal molar ratio of Ch3HgCl to Na2SeO3 in the medium is on the order of one-tenth. These two observations suggest that methyl mercury interferes with sites for selenite transport into the cell. The optimal HgCl2Na2SeO3 molar ratio in the growth medium varies from 1.2 to 2.0. At protective levels, selenite increases uptake of mercuric chloride on a per-cell basis. The molar ratio of uptake of the two substances varies with their ratio in the medium, but not in a linear fashion. These results suggest a minimum of two different protective interactions between mercuric chloride and sodium selenite.