Effects of selenium deficiency on fatty acid metabolism in rats fed fish oil-enriched diets.

The hepatic fatty acid metabolism was investigated in rats stressed by selenium deficiency and enhanced fish oil intake. Changes in the composition of lipids, peroxides, and fatty acids were studied in the liver of rats fed either a Sedeficient (8 microg Se/kg) or a Se-adequate (300 microg Se/kg) diet, both rich in n-3 fatty acid-containing fish oil (100 g/kg diet) and vitamin E (146 mg alpha-tocopherol/kg diet). The two diets were identical except for their Se content.

Experimental studies of electroosmotic flow dynamics during sample stacking for capillary electrophoresis.

Electroosmotic flow dynamics during a field-amplified sample stacking experiment have been studied experimentally using the periodic photobleaching of a dilute, neutral fluorophore added to the separation buffer. The effects of hydrodynamically injecting different sample plug lengths containing a mixture of arsenic compounds dissolved in 0.125 mM (120, 240, and 600 s) and 41.

Speciation of selenium in the mammalian organism.

As almost all of the selenium present in the mammalian organism is protein-bound, speciation is mostly concerned with the determination of the different selenium-containing proteins. Information on their distribution and their concentrations in the different tissues of the rat was obtained by means of tracer procedures which, after application of 75Se-selenite with a very high specific activity to selenium-depleted animals and electrophoretic separation of the labelled proteins, allow the determination of these compounds in the pmol to fmos range. A method was developed for the determination of selenocysteine and selenomethionine in the selenium-containing proteins.

Two new selenoproteins found in the prostatic glandular epithelium and in the spermatid nuclei.

After labeling of rats in vivo with 75Se and protein separation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis more than 25 Se-containing bands could be distinguished. Of those proteins which were detected only in certain compartments and might therefore have tissue-specific functions, two were chosen for detailed investigation. A 15 kDa-protein was found in the prostatic epithelium where it accounted for about two thirds of the protein-bound 75Se.

Newly found selenium-containing proteins in the tissues of the rat.

The Se-containing proteins in 27 tissues of the rat were investigated by in vivo labeling with 75Se-selenite, separation of the tissue homogenate proteins by SDS-polyacrylamide gel electrophoresis, and determination of the labeled proteins by autoradiography. By using Se-depleted rats and a 75Se-tracer with a high specific activity, Se compounds present at only very low concentrations could be detected. Besides the 13 Se-containing proteins previously described, for which apparent molecular masses of 12, 15, 18, 20, 22, 25, 28, 34, 56, 60, 65, 70, and 75 kD have been found here, a further 15 75Se-labeled bands, with apparent molecular masses of 8, 10, 15.