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 microM. 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 microM. Sulfite inhibited the uptake of selenite by hepatocytes.