COMPARATIVE STUDY OF CADMIUM TOXICITY IN FISH (Danio rerio y Poecilia reticulata)

SANCHEZ ES; PISTONE C; ALVAREZ SM; ENRIZ D; GIANNINI F

Congreso; 39na Reunión Anual de la Sociedad de Biologia de Cuyo; 2021

The fish experimental models are ideal to evaluate toxicity as well as for research in embryology, neurobiology,endocrinology, environmental biology and other areas. We are performing fish test since 15 years ago usingbioassays designed by U.S. Fish and Wildlife Service. Columbia National Fisheries Research Laboratory basedon the availability of specimens and the substances to assay, and are evaluating different biomarkers such asGOT and GTP (mainly hepatic enzymes), AChE (enzyme primarily found at postsynaptic neuromuscularjunctions especially in muscles and nerves) and creatinine (waste product formed by the kidneys).Environmental contamination of Cadmium (Cd), derived from agricultural and industrial sources, has a highimpact on the ecosystems, which are extremely susceptible to the effect of the toxicity of Cd. The toxicity of thedifferent axenic is evaluated in acute assay (short time, high doses) and chronic assay (prolonged time, lowdoses). The acute adverse effects relate mostly to the ratio of mortality in 96 hours of exposure; meanwhile inthe chronic assay the exposure last 21 days or more. In this study, we performed an acute and chronic test withjuvenile specimens of Danio rerio (zebrafish) and Poecilia reticulata. The results of acute toxicity after exposureto several solutions of Cd chloride up to 100 mg/lt showed any mortality in juvenile specimens of both species.Regarding chronic toxicity, we performed the analysis of different biomarkers such glutamic oxaloacetictransaminase (GOT), glutamic pyruvic transaminase (GPT), acetylcholinesterase (AChE) and creatinine at twodifferent doses (1 and 2 mg/lt). The exposure to Cd for the long term caused a significant increase of the hepaticenzyme GOT and creatinine in both species. In contrast, we observed a remarkable decreased the levels ofAChE in Danio rerio as well as in Poecilia reticulata. The analysis of these data leads us to conclude that thechronic effects observed in both species are in the same trend but in different levels and in a dose dependentmanner. So that, these organic and functional effects may affect fish survival, bioavailability and physiologyimpacting their natural environment. The results highlight the concerns on Cd pollution and remark the use offishes as biomarkers and its application on environmental toxicology studies for the great value of ecologicalprotection