Avaliação de marcadores de integridade celular, genotoxicidade, reparo de DNA e hemocaterese em tilápias expostas a cádmio

Abstract

Several environmental conditions induce different damages to organisms. When damage occurs in the DNA, it is considering genotoxics and characterized by alterations in gene expressions, defects in chromosome replication and repair processes. These events could lead to genetic instability and cells death. In this study, we used cadmium as inducing agent of genotoxicity in tilapia. After the analysis of erythrocytes, we established the temporal relationship between viability markers, repair and cellular damage. The cadmium concentrations were analyzed in various organs and tissues of tilapia such as spleen, hepatopancreas, gills, head kidney, muscle and blood. The spleen presented the higher cadmium content after exposure. Published papers and additional data in this study indicate that the genotoxic effect of cadmium is associated primarily to its systemic concentration. The viability and cell repair parameters participate sequentially in different ways to different concentrations and times tested. Additionally, hemocateretic processes mainly performed by spleen melanomacrophage centers suggest their involvement in removal of nuclear alterations from blood stream. Among the erythrocyte nuclear alterations studied, the frequencies of blebbed, vacuolization and nuclear condensation were changed during exposure and lobed and bud in depurate period. In parallel, we proposed quantifying erythrocyte nuclear alterations using a flow cytometry technique and established an analytical method for the determination of cadmium in tissues using tilapia as a biological model.