Selenium Metabolism

Rats given labeled selenate excreted substantially more selenium into the urine when sulfate was injected or was present in the diet. Although the increased urinary excretion of selenium was accompanied by a decreased excretion into the gastrointestinal tract, there were small but consistent decreases in the retention of selenium in the blood, liver, kidneys, and carcass. Sulfate was much less effective in altering the distribution or excretion of labeled selenite. Measured by the growth of young male rats, dietary sulfate partially alleviated a chronic selenium toxicity induced with selenate. The effect of sulfate on growth was roughly comparable to its effect on selenium retention. Sulfite also improved the growth of animals receiving selenate. Growth in the presence of selenite was improved somewhat by sulfate and to a lesser extent by sulfite.