Chronic Arsenic Exposure in CC Mice

Adult males (2–4 months old) CC mice were obtained from the UNC Systems Genetics Core Facility (SGCF). The selection of CC strains and the number of replicates per CC strain were dictated by the SGCF pilot project format (12 strains with 4–6 mice per strain) and by the availability of male mice of CC strains maintained by the SCGF at the start of the study (December 1, 2017). Mice were housed (1–5 per cage) under controlled conditions with 12-h light/dark cycle at 22 ± 1 °C and 50 ± 10% relative humidity. After a 3-day acclimation, mice in each strain were randomly divided into two treatment groups (N = 4–5). One group was exposed to 0.1 ppm and the other to 50 ppm iAs (sodium arsenite, NaAsO₂, ≥ 99% pure; Sigma-Aldrich, St. Louis, MO, USA) in drinking (deionized) water ad libitum. Mice in all groups were fed a semi-purified AIN-93G diet (Envigo Teklad, Madison, WI, USA). In our previous studies, the concentrations of iAs in this type of diet ranged from 11 to 50 ppb (Douillet et al. 2017 (link); Huang et al. 2018a (link), b (link)). Water consumption was monitored weekly. All procedures involving mice were approved by the University of North Carolina Institutional Animal Care and Use Committee.