Uma comparação toxicológica entre dois sais de Urânio em água do mar artificial em Artêmia salina

Abstract

Uranium is a heavy, ubiquitous, natural metal found in various chemical forms in all soils, rocks, seas and oceans. Human exposure occurs through food such as fish and seafood, and even through ingestion of plants grown in contaminated water areas. It is observed that the aquatic environment is extremely affected by this contaminant so it is necessary to assess the environmental risk generated by the discharge of this metal. Artemia saline (AS) is a microcrustacean responsible for filtration, bioaccumulation and transfer of various heavy metals to various species of fish and crustaceans. Thus, the objective of this study was to evaluate the toxicity of two uranium salts: uranium acetate (AU) and uranium nitrate (NU) in AS exposed for 24 hours. The results shows that AS were more sensitive to treatment with UN (LC50 ≈15 μM) compared to UA (LC50 ≈245 μM), thus indicating the high toxicity of this U salt. This study also revealed that both U compounds caused an increase in TBARS levels and a high concentration of UN increased the formation of reactive oxygen species. Accordingly, UA and UN significantly decrease catalase activity (100 μM and 10 μM, respectively). In addition, this study showed an increase in necrotic / apoptotic cell death caused by NU and both U salts caused a decrease in locomotor activity after 9 hours of exposure. It was also identified that only UN was able to decrease AChE activity, suggesting that UN may cause an increase in acetylcholine in AS synaptic junctions. Thus, this study shows that alternative animal model using AS may be interesting for some in vivo and ex vivo toxicity analyzes. In addition, we demonstrate distinct sensitivity for both forms of uranium, contributing significantly to the understanding of the ecotoxicity of this heavy metal.