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(W/EH028) Pathological alterations in adult seabream, Sparus aurata, exposed to water and dietary 2,3,7,8 tetrachlorodibenzo-p-dioxin. Arellano, Juana1, Ortiz, Juan2, González de Canales, Luisa2, Sarasquete, Carmen3, 1 2 3 ABSTRACT- TCDD has been shown to accumulate in the tissues of fish. Some fish species, are sensitive to the effects of TCDD. While a number of chemicals structurally similar to TCDD can cause adverse effects in fish through the same mode of action, TCDD is the most potent of the class of polyhalogenated diaromatic hydrocarbons (Giesy and Kannan, 1998). The aim of this study was to detect the hepatic and gill alterations in adult seabream (Sparus aurata) following 7 days exposure to 2,3,7,8,-tetrachlorodibenzo-p-dioxin (1 pg/L) by electron and optical microscopy. Toxicity of TCDD was clearly demonstrated: the liver developed large lysed areas and hepatocytic alterations. However, the majority of the parenchyma was composed of hepatocytes displaying typical features of increased metabolism: development of rough reticulum, increase in size of nucleus and nucleolus, glycogenic augmentation and principally an increase of lipid droplets. On the gills, secondary lamellar epithelium showed hyperplasia and hypertrophy, lamellar fusions on the edge of the filaments, and during the final days of the TCDD exposition swelling of the lamellar epithelium and hyperplasia of goblet cells were observed. Key words: seabream, 2,3,7,8 tetrachlorodibenzo-p-dioxin, liver, gills |
