Enzymes from kidney, gill and brain tissues of Astyanax bimaculatus (lambari) as biomarkers of environmental impact in the Una River basin

The Una River and its basin constitute an important water source for public supply in the municipality of Taubate (SP, Brazil). The present work aimed to investigate biochemical markers of environmental pollution in the Una river basin using enzymes extracted from the kidneys, gills and brains of Astyanax bimaculatus , a fish commonly found in this basin. Tissue levels of superoxide dismutase (SOD), catalase (CAT), malate dehydrogenase (MDH), lactate dehydrogenase (LDH) and acetylcholinesterase (AChE) were determined in tissues of A. bimaculatus collected in water bodies localized at Fazenda Piloto of the University of Taubate (P1), the Remedios municipal road (P2) and at a small lake near the neighborhood of Ipiranga (P3), all located in the municipality of Taubate. The lowest activities of renal and gill SOD were found in fish collected from P2 and P3, respectively. Renal and branchial CAT, renal MDH and LDH, as well as the activity of cerebral LDH were not affected by collection site. The activities of brain MDH and AChE were higher in fish from P3 in comparison with P1. These results along with earlier published findings, indicate that the hepatic SOD and CAT, gill SOD and LDH, muscle MDH and brain MDH and AChE are sensitive to contamination in the environment and hence can be considered as good candidate biomarkers of environmental change in the Una River basin.