DOES PERCHLORATE INDUCE NON-ALCOHOLIC FATTY LIVER DISEASE IN DEVELOPING ZEBRAFISH?

Abstract

Perchlorate is a chemical contaminant found in various food and water sources. Millions of Americans and individuals around the world are exposed to perchlorate primarily from military and engineering manufacturing wastes[1]. Previous research has shown that perchlorate causes hypothyroidism in vertebrates, including people[2]. Stickleback fish (Gasterosteus aculeatus) have displayed hypothyroidism and signs of non-alcoholic fatty liver disease (NAFLD) when exposed to perchlorate[3]. NAFLD is excess fat deposits in liver tissue that can lead to various negative health outcomes such as liver cancer or liver failure[4]. One hundred and fifty-five zebrafish (Danio rario) were placed into four exposure groups: control, 10 ppb, 10 ppm, and 100 ppm of perchlorate. Between 100-115 days post-fertilization, the zebrafish were euthanized and fixed in 10% buffered formalin. The tissues were processed and embedded in paraffin wax, sectioned, and treated with H & E staining[5]. The samples were analyzed at 40x magnification and LASX software was used to calculate total lipid area droplet size and roundness and number of lipid droplets and median droplet size were calculated with these data. The data for each of the treatment groups were compared using a one-way ANOVA. The results indicate that perchlorate exposure does not impact the total lipid area, median droplet size, or number of lipid droplets in zebrafish. The difference in response to perchlorate exposure and liver tissue in zebrafish and stickleback fish may be due to genetic or environmental differences in the species[6].