Metal contamination in mice under conventional husbandry

Metal release after implantation of medical metal implants can induce serious symptoms of hypersensitivity. A variety of immunologic reactions to metal particles has been demonstrated by a number of studies. To analyze the effect of metal abrasion in the thoracic cavity we aimed at developing a suitable mouse model. However, during the course of the study, high baseline concentrations of both chromium and nickel in conventional husbandry systems were observed. This finding necessitated modifications to the husbandry conditions. Groups of male C57BL/6 J mice were transferred into metal-free cages and fed a diet with reduced nickel and chromium content. After eight weeks, urinary concentrations of chromium and nickel were reduced, which was statistically significant in most groups for chromium and in one group for nickel. Due to their immunological impacts, we report the need to understand potential metal contaminations under conventional husbandry conditions in experimental set ups.