Toxicity, metabolism and absorption of selenite by isolated rat hepatocytes

The uptake of various levels of selenite by isolated rat hepatocytes was investigated. The LD₅₀ value of selenite was about 500 μM. The activity of lactic dehydrogenase in the medium was correlated with cell viability as determined by trypan blue exclusion. After incubation of selenite with hepatocytes, protein-bound Se was the predominant form (80–90% of the cellular Se) present. Subcellular fractionation indicated that most of the radioactivity was present in the cytosol when hepatocytes were incubated with ⁷⁵Se-selenite. The uptake of ⁷⁵Se by isolated rat hepatocytes was linear with selenite concentration up to the highest amount tested, 200 μM. Sulfite inhibited the uptake of selenite by hepatocytes.