Variations in liver histology and P-gp expression among fish species in Doce River Basin, Brazil: implications for pollution sensitivity.

Fish may have different sensitivity to pollutants present in the water. We analyzed the liver histology, and P-gp expression in six species of fish from the Doce River basin. Fish were caught at six different points in the Doce River, and liver samples were taken for histological analysis.

Histological and molecular changes in gill and liver of fish (Astyanax lacustris Lütken, 1875) exposed to water from the Doce basin after the rupture of a mining tailings dam in Mariana, MG, Brazil.

The effects of the rupture of a mining tailings dam were investigated using the gills and liver of Astyanax lacustris as a proxy for environmental quality. The fish were exposed for seven days to water sampled forming four groups: upstream of the dam rupture (P1), and 22 km (P2); 48 km (P3); and 70 km (P4) downstream from the dam rupture in the Doce River basin. The control group received dechlorinated tap water.

Estuarine fish assemblages present a species-specific difference in the multixenobiotics resistance activity.

We investigated the activity of the multixenobiotic resistance (MXR) phenotype, a biological defense system in aquatic organisms, in the fish assemblages of two tropical estuaries with different degrees of environmental impacts, the Paraiba River and Mamanguape River Estuaries. The aim of this work was to compare the activity of the MXR phenotype of different fishes to test the hypothesis that each species has an inherent activity level and to use this activity as a bioindicator of aquatic contamination. We assessed the MXR activity of the gills, using rhodamine B (RB) accumulation assay.