Contrasting Cu, Fe, and Zn isotopic patterns in organs and body fluids of mice and sheep, with emphasis on cellular fractionation
Abstract
We report Cu, Fe, and Zn natural isotope compositions in organs, body fluids, diets and feces of mice and sheep. Large and systematic isotope variability is observed, notably in the δ66Zn in liver and δ65Cu in kidneys, but significant differences exist between mice, sheep and humans, especially in the δ66Zn value of blood. The results are interpreted with reference to current knowledge of metal trafficking and redox conditions in cells. In general, the light isotopes preferentially fractionate into ‘softer’ bonds involving sulfur such as