Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: 12/2/2002
Publication Date: 3/14/2003
Citation: Keck, A., Finley, J.W. 2003. Selenium (se) enriched beef, wheat or broccoli or the salt selenate differ in the ability to increase thioredoxin reductase (tr) and glutathione peroxidase (gpx) in rats [abstract]. Journal of Federation of American Societies for Experimental Biology. 17(5):A1136.
Technical Abstract: Wheat and beef are the most abundant sources of Se in a western diet; they contain Se primarily in the form of selenomethionine and selenocysteine. Broccoli is a Se-accumulator that contains large amounts of Se-methyl selenocysteine. Bioavailability of Se from these foods was investigated by measuring the ability of Se to activate the selenoproteins TR and GPx. Rats were fed for 6 wk a torula-yeast based diet supplemented with Se from selenate or high-Se beef, wheat or broccoli in amounts that provided 0 to 2 mg Se/kg diet. Enzyme activities were modeled and estimates of kt and Jmax were obtained. In the liver and kidney, the lowest estimate of kt was obtained with selenate diets, however Jmax also tended to be lowest. The estimate of kt tended to be higher for broccoli and beef, but Jmax also tended to be high. Estimates of kt and Jmax for wheat depended on the organ as well as the enzyme measured. These data demonstrate that not all food sources of Se are equally available for selenoprotein synthesis.