Chronic Arsenic Exposure in Mice

All procedures involving mice were approved by the University of North Carolina (UNC) Institutional Animal Care and Use Committee. Male and female C57BL/6J WT mice were obtained from Jackson Laboratories (Bar Harbor, ME, USA) and let to acclimatize at the UNC Animal Facilities for one week. Male and female As3mt-KO mice on a C57BL/6 background (Drobná, et al. 2009 (link)) were bred at the UNC Animal Facilities. Both WT and As3mt-KO mice were housed under controlled conditions with 12-h light/dark cycle at 22±1°C and 50±10% relative humidity (3–5 mice per cage) and with unlimited access to pelleted 2920X Teklad rodent chow (Envigo, Madison, WI, USA). All mice were 21-week old at the beginning of the study when they were randomly assigned to treatment groups with 10–14 animals per group. Both WT and As3mt-KO mice drank for 24 weeks (ad libitum) either deionized water or deionized water containing sodium arsenite (AsNaO₂, ≥99% pure; Sigma-Aldrich, St. Louis, MO, USA) at final concentrations of 0.1 or 1.0 mg As/L (i.e., 0.1 or 1 ppm). Water with sodium arsenite was prepared weekly to minimize oxidation of iAs^III to iAs^V. Food and water consumption and body weight were monitored in all treatment groups weekly.