Meeting Abstract
Perchlorate is a pervasive, water-soluble contaminant that competitively inhibits the sodium/iodide symporter, reducing the available iodine for thyroid hormone synthesis. Insufficient iodide uptake can lead to hypothyroidism and metabolic syndromes. Because metabolism, obesity and non-alcoholic fatty liver disease (NAFLD) are tightly linked, we hypothesized that perchlorate would act as an obesogen and cause NAFLD by causing the accumulation of lipids in developing threespine stickleback liver. We performed an upshift/downshift exposure regime (clean water to perchlorate exposed water or perchlorate exposed water to clean water) on stickleback embryos at three concentrations (0 mg/L, 30 mg/L and 100mg/L) over the course of 305 days. Adult stickleback were euthanized, collected for histology, H&E stained and analyzed for their liver morphology. Specifically, we counted the number of lipid droplets, measured the area of each droplet and the total lipid area of a representative section of liver. We found that perchlorate treated fish showed greater numbers of lipid droplets, larger lipid droplets and had a larger percentage of lipid in their liver than control fish. These data indicate that perchlorate is causing NAFLD and hepatic steatosis in stickleback at concentrations commonly found at contaminated sites. These data also indicate the potential of perchlorate to act as an obesogen. Future studies should investigate the obeseogenic capacity of perchlorate by examining organ specific lipid accumulation. Work is also needed to determine the mechanisms by which perchlorate induces lipid accumulation.
