Selenium metabolites in urine: a critical overview of past work and current status.
BACKGROUND
Selenium is an essential trace element that also elicits toxic effects at modest intakes. Investigations of selenium metabolites in urine can help our understanding of the transformations taking place in the body that produce these beneficial and detrimental effects. There is, however, considerable discord in the scientific literature regarding the selenium metabolites thought to play important roles in these biotransformation processes.


METHODS
We critically assessed the published reports on selenium urinary metabolites, from the first report in 1969 to the present, in terms of the rigor of the data on which structures have been proposed.


BACKGROUND
We present and discuss data from approximately 60 publications reporting a total of 16 identified selenium metabolites in urine of humans or rats, a good model for human selenium metabolism. We assessed the analytical methods used and the validity of the ensuing structural assignments.


CONCLUSIONS
Many of the studies of selenium metabolites in urine appear to have assigned incorrect structures to the compounds. The long-held view that trimethylselenonium ion is a major human urinary metabolite appears unjustified. On the other hand, recent work describing selenosugars as major urinary metabolites looks sound and provides a firm basis for future studies.
Francesconi
Kevin A
KA
Institute of Chemistry-Analytical Chemistry, Karl-Franzens University Graz, Graz, Austria. kevin.francesconi@uni-graz.at
Pannier
Florence
F
D000818:Animals; D049673:History, 20th Century; D006801:Humans; D016566:Organoselenium Compounds / Q000378:metabolism / Q000633:toxicity / Q000652:urine; D012643:Selenium / Q000378:metabolism / Q000633:toxicity / Q000652:urine*; D018036:Selenium Compounds / Q000378:metabolism / Q000633:toxicity / Q000652:urine
D016566:Organoselenium Compounds; D018036:Selenium Compounds; D012643:Selenium