| Autor: |
de Sabóia-Morais SMT; Laboratory of Cellular Behavior, Department of Morphology, Biological Sciences Institute, Federal University of Goiás, Goiânia, Brazil., de Lima Faria JM; Laboratory of Cellular Behavior, Department of Morphology, Biological Sciences Institute, Federal University of Goiás, Goiânia, Brazil., da Silva Rabelo JC; Laboratory of Cellular Behavior, Department of Morphology, Biological Sciences Institute, Federal University of Goiás, Goiânia, Brazil., Hanusch AL; Department of Histopathology, Clinical Hospital, Goiania, Brazil., Mesquita LA; Laboratory of Cellular Behavior, Department of Morphology, Biological Sciences Institute, Federal University of Goiás, Goiânia, Brazil., de Andrade Silva R; Laboratory of Cellular Behavior, Department of Morphology, Biological Sciences Institute, Federal University of Goiás, Goiânia, Brazil., de Oliveira JM; Rede Nordeste de Biotecnologia (RENORBIO), Institute of Chemistry and Biotechnology, Federal University of Alagoas, Maceió, Brazil.; Laboratory of Applied Animal Morphophysiology, Histology and Embryology Section, Institute of Biological Sciences and Health, Federal University of Alagoas, Maceió, AL, Brazil., de Jesus LWO; Laboratory of Applied Animal Morphophysiology, Histology and Embryology Section, Institute of Biological Sciences and Health, Federal University of Alagoas, Maceió, AL, Brazil. |
| Abstrakt: |
There is a growing concern regarding the adverse risks exposure to cylindrospermopsin (CYN) might exert on animals and humans. However, data regarding the toxicity of this cyanotoxin to neotropical fish species are scarce. Using the fish species Poecilia reticulata , the influence of CYN concentrations equal to and above the tolerable for drinking water may produce on liver was determined by assessing biomarkers of antioxidant defense mechanisms and correlated to qualitative and semiquantitative histopathological observations. Adult females were exposed to 0.0 (Control); 0.5, 1 and 1.5 μg/L pure CYN for 24 or 96 hr, in triplicate. Subsequently the livers were extracted for biochemical assays and histopathological evaluation. Catalase (CAT) activity was significantly increased only by 1.5 μg/L CYN-treatment, at both exposure times. Glutathione -S-transferase (GST) activity presented a biphasic response for both exposure times. It was markedly decreased after exposure by 0.5 μg/L CYN treatment but significantly elevated by 1.5 μg/L CYN treatment. All CYN treatments produced histopathological alterations, as evidenced by hepatocyte cords degeneration, steatosis, inflammatory infiltration, melanomacrophage centers, vessel congestion, and areas with necrosis. Further, an I ORG >35 was achieved for all treatments, indicative of the presence of severe histological alterations in P. reticulata hepatic parenchyma and stroma. Taken together, data demonstrated evidence that CYN-induced hepatotoxicity in P. reticulata appears to be associated with an imbalance of antioxidant defense mechanisms accompanied by histopathological liver alterations. It is worthy to note that exposure to low environmentally-relevant CYN concentrations might constitute a significant risk to health of aquatic organisms. |
