Histopathological effects of chronic exposure to lead on kidneys of brown trout (Salmo trutta m. Fario)

The aim of the present study was to investigate the histopathological changes on the kidneys of the brown trout (Salmo trutta m. Fario) inflicted by per os lead poisoning in the 46-week experimental period. The fish were kept in well-oxygenated freshwater basins. Approximately calculated toxic doses of lead-acetate for fish were 550 mg/kg. Following the experimental period, fish organs, in particular kidneys, were examined by light microscopy. Only fish with lesions observed in kidneys were further examined by electron microscopy. An accumulation of proteinaceous material in the glomeruli of the kidneys, and thickening of the basal membrane were observed histopathologically. This proteinaceous material was also observed in the lumina of the kidney tubules. Electron microscopic examination completely supported this finding. Furthermore, to the authors' previous knowledge, undocumented damage of the brush borders of the proximal kidney tubules was also observed