Effects of low zinc status and arsenic exposure in mice

During fall term of 2015 and winter and spring term of 2016 I assisted in research within Dr. Emily Ho’s lab. The project that I assisted in looked at the effects of low zinc status and arsenic exposure in mice. Zinc is an essential micronutrient involved in numerous cellular processes including its role as an antioxidant. Arsenic is a naturally occurring metal found within the earth’s crust. Humans can come into contact with arsenic through contaminated food and water sources. Arsenic exposure is associated with an increase in reactive oxygen species. The goal of our study was to determine if zinc deficiency or arsenic exposure caused an increase in oxidative damage. \ud For this study we used 5 groups 8 mice. The mice were randomly assigned to either a zinc adequate group, which were fed a diet containing zinc equivalent to RDA recommendations, or a zinc deficient group, which was fed a diet containing very low zinc levels. Mice were also randomly assigned to 3 groups which contained 0 ppb, 50 ppb and 500 ppb arsenic in their drinking water. The mice received the assigned treatments for 4 weeks. \ud After the conclusion of the treatment, mineral levels of calcium, copper, iron, magnesium, selenium and zinc were determined using ICP-OES (Inductively coupled plasma optical emission spectrometry). Liver damage was evaluated by examining plasma ALT (alanine aminotransferase) levels which is a biomarker for liver damage. Oxidative DNA damage was evaluated in liver genomic DNA using 8-OHdG DNA damage ELISA. \ud We determined that arsenic exposure reduced magnesium and selenium content within plasma. Both zinc deficiency and arsenic exposure increased levels of 8-OHdG, and zinc deficiency increased levels of ALT