Azevedo_2013_Ecotoxicol.Environ.Saf_96_220

In order to understand environmental health by the use of a bioindicator species in estuaries, biochemical responses observed in the catfish Cathorops spixii such as catalase (CAT), glutathione-S-transferase (GST), lipid peroxidation (LPO) and acetylcholinesterase (AChE) were evaluated in liver and muscle. Furthermore, histological changes were also verified in liver and gills preparations. Fish were collected in three sites of the Santos-Sao Vicente estuary located at Sao Paulo (Brazil), subjected to varying levels of inputs of pollutants. For a reference site, specimens were sampled at Cananeia estuary at southern coast of Sao Paulo, a region with low anthropogenic influence. In general, no significant seasonal differences in antioxidant enzymes and lipid peroxidation responses were found in the organisms from the Cananeia estuary. However, in the polluted estuary (Santos-Sao Vicente), biochemical responses were observed by increases in GST hydroperoxides and decreases in AChE activities in the summer. Inhibition of AChE expression in fish from different areas of the Santos-Sao Vicente estuary in the summer was also found and can indicate neurotoxic effects in these organisms. Histopathological observation of gill and liver showed severe lesions, such as lamellar fusion and necrosis.