title: 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 δ(66)Zn in liver and δ(65)Cu in kidneys, but significant differences exist between mice, sheep and humans, especially in the δ(66)Zn 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 cysteine and glutathione, whereas heavy isotopes fractionate into 'harder' bonds involving nitrogen (histidine) and even more oxygen, notably hydroxides, phosphates, and carbonates. Bonds involving the reduced forms Cu(+) and Fe(2+) are enriched in the light isotopes relative to bonds involving the oxidized Cu(2+) and Fe(3+) forms. Differences in blood Zn isotope abundances between mice, sheep and humans may reflect a different prevalence of Zn ZIP transporters. The isotopically heavy Cu in the kidneys may reflect isotope fractionation during redox processes and may be relevant to ascorbate degradation into oxalate.
authors: CNRS UMR 5276 "Laboratoire de Géologie de Lyon", Ecole Normale Supérieure. 46, Allée d'Italie, 69634 Lyon, France. Vincent.Balter@ens-lyon.fr.
authors: Vincent
authors: V
authors: Balter
authors: Aline
authors: A
authors: Lamboux
authors: Antoine
authors: A
authors: Zazzo
authors: Philippe
authors: P
authors: Télouk
authors: Yann
authors: Y
authors: Leverrier
authors: Jacqueline
authors: J
authors: Marvel
authors: Aidan P
authors: AP
authors: Moloney
authors: Frank J
authors: FJ
authors: Monahan
authors: Olaf
authors: O
authors: Schmidt
authors: Francis
authors: F
authors: Albarède
mesh_terms: D000818:Animals; D001826:Body Fluids / Q000737:chemistry*; D003300:Copper / Q000032:analysis*; D006801:Humans; D007501:Iron / Q000032:analysis*; D007554:Isotopes / Q000032:analysis*; D051379:Mice; D012756:Sheep; D015033:Zinc Isotopes / Q000032:analysis*
chemical_list: D007554:Isotopes; D015033:Zinc Isotopes; D003300:Copper; D007501:Iron