Uptake of selenotrisulfides of glutathione and cysteine by brush border membranes from rat intestines.

The uptake of selenodiglutathione and selenodicysteine was compared to that of selenite by brush border membrane vesicles (BBMV) prepared from rat intestinal tracts. It was found that it is critical to maintain a pH of 6.0 or below to prevent the spontaneous breakdown of these compounds. When conducted at pH 6.0, the uptake of selenodiglutathione and selenodicysteine was more than ten times faster than for selenite selenium. Ligated intestinal loop studies were conducted to determine if similar results would be obtained in vivo. In comparison to selenite, selenium absorption was enhanced 68% and the transfer to the body increased 2.4-fold when selenium as selenodiglutathione was placed in the ileum. The absorption of selenium as selenodicysteine was increased by 57% and the transfer doubled in comparison to selenite when placed in the ileum. Thus, the stimulated absorption of selenite by glutathione or cysteine appears to be through the formation of complexes with these compounds.