Abstract
Among the most startling observations in mammalian toxicology is that a lethal dose of selenium can be overcome by an otherwise lethal dose of arsenic. We report the molecular basis of this antagonism. Using X-ray absorption spectroscopy we have identified a new arsenic−selenium compound in the bile of rabbits injected with aqueous selenite and arsenite solutions. This compound contains equimolar arsenic and selenium and exhibits X-ray absorption spectra which are essentially identical with those of a synthetic species in solution which we have identified spectroscopically as the seleno-bis(S-glutathionyl) arsinium ion. The in vivo detection of this compound links the mammalian metabolism of arsenite, selenite, and sulfur. It provides a molecular basis for the antagonistic interaction between these metalloid compounds, and a potential explanation of the association of cancer with prolonged intake of inorganic arsenic in humans.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
