Alterações histológicas de peixes como biomarcadores da contaminação aquática

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

Several streams from big cities are contaminated with industrial, domestic and agricultural effluents. The indiscriminated sewage and the release of substances considered risky into these streams may lead to damages in the water environment that may be considered as a great source of stress for the biotic community. The pollutants may cause lesions in the tissues and organs of fish that live in degraded environments. Thus, the histopathological analyses are considered sensitive tools to detect the presence and effects of chemical compounds in organs-aim. In this work, two species of tetra fish of the genus Astyanax (Characidae, Tetragonopterinae) were collected in different points of an urban stream. The occurrence of histopathological alterations were evaluated in the gills, liver and kidney of A. scabripinnis collected in five points of the stream and for A. altiparanae, collected in three points of the same stream. Renal histopathological analysis and morphometric analysis of the interrenal cells were carried out. The histopathological study showed severe alterations in both species studied. A. scabripinnis showed alterations in the gills: epithelial lifting, hyperplasia and hypertrophy of the epithelial cells of the lamella and the filament, lamellar fusion and aneurism; in the liver: glycogen depletion, nuclear and cytoplasmic vacuolization, nuclear and cytoplasmic hypertrophy, hyperemia and cell and nuclear degeneration of liver cells; and in the kidney: cytoplasmic vacuolization associated with granular and hyaline degeneration, and necrosis in the proximal and distal tubules, new nephrons and alterations in the renal corpuscle with the presence of red blood cells and the reduction of Bowman’s space. The tetra fish of the species A. altiparanae showed the same alterations in the kidney as the A. scabripinnis’ and the morphometric analysis of the interrenal cells of these fish showed an increase in the cell and the nucleus area as well as in the nucleus diameter, showing to be hypertrophied when compared with the interrenal cells of the fish from a reference location. These results show the incidence of histopathological alterations in the A. scabripinnis’ organs, as well as in the A. altiparanae’s kidney, and suggest a chronic stimulation of the axis hypothalamus – hypophysis – interrenal cells of the tetra fish that live in the urban stream, showing clearly the impairment of the health of these fish due to the presence of toxic agents in the water. The parameters analyzed showed to be sensitive tools that may be used as biomarkers for the evaluation of the water contamination in environmental monitoring programs.

ASSUNTO(S)

peixe - contaminação aquatic biology biologia aquática fish histopatologia contamination

ACESSO AO ARTIGO

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