BEHAVIOR OF METHYLATED METABOLITES OF SEL ENIUM IN RATS ORALLY-ADMINISTERED WITH VARIOUS DOSE LEVELS OF SODIUM SELENITE

The behavior of methylated selenium metabolites in the urine and in th e expiration of rats which administered orally at various dosages (0, 0.31, 1.25 and 5.00 mg Se/kg diet) of selenite, was investigated. Tbe contents of selenium in organs depended on the dose levels. Using Seph adex gel chromatograms oi rat liver cytosols it was shown that at the toxic levels the amount of selenium more than that physiologically req uired for the active site of GSH-Px may bind to the other site. Excret ions of trimethylselenonium ion (TMSe) in the urine and dimethyl selen ide (DMSe) in exhaust gas increased with increasing accumulative level s of selenium. The excretion behaviors of TMSe and DMSe for 30 d after administration showed the same content level only at toxic dosage (av erage selenium intake level : 95 mu g Se/d). The present study suggest ed that as exposed by deficient to nutrient levels, selenium levels an d GSH-Px activity in organs may be used to evaluate selenium level in the body, and the amount of TMSe in the urine and DMSe in exhaust gas may be utilized as indicators to predict the toxic selenium exposure l evel.