Biochemical and (ultra)structural hepatic perturbations of Brachydanio rerio (Teleostei, Cyprinidae) exposed to two sublethal concentrations of copper sulfate

The aim of this study was to compare biochemical and (ultra)structural pert urbations induced by Cu in the liver of Brachydanio rerio exposed for 14 da ys to sublethal concentrations of copper and then replaced for 14 days to c lean water. Toxicity of Cu was clearly demonstrated: simultaneously to Cu a ccumulation, the liver developed large lysed al ens and hepatocytic alterat ions. However, the majority of the parenchyma was composed of Functional da rk hepatocytes displaying typical feature of increased metabolism: developm ent of rough reticulum, increase in size of nucleus and nucleolus. glycogen ic depletion. Increase in hepatic protein content and of anti-oxidative def ences (glutathione content, catalase and glutathione-S-transferase (GST) ac tivities) indicated that the overall response of the liver was adaptative. In all hepatocytes a cord-like structure of the nucleoli was suspected to b e associated to metal deposition. After 14 days depuration, the liver still contained high Cu concentrations and the hepatic alterations were not reve rsed. Such complementary studies are necessary for a better understanding o f the deleterious effects of pollutants and for the development of biomarke rs For metal toxicity. (C) 2000 Elsevier Science B.V. All rights reserved.