BIANCHI Virginia Angelica
congresos y reuniones científicas
Modulation of immune and antioxidant responses to Escherichia coli by azinphos-methyl in the freshwater mussel Diplodon chilensis.
Congreso; SETAC Latinoamerican 11st Biennial Meeting; 2015
The aim of this work is to characterize the immune response and the oxidative balance in Diplodon chilensis upon 72 h exposure to environmentally relevant concentrations of AZM. To achieve this, mussels were collected from an unpolluted site and acclimated in laboratory for 3 days. Then, six groups were set: G1) Control: fed with Scenedesmus vacuolatus (SV), G2) Acetone control, G3) Exposed to Escherichia coli (50,000 cell/mL), G4) Exposed to AZM 0.2 ppm, G5) Exposed to acetone for 3 days and then to E. coli for 3 days, G6) Exposed to AZM for 3 days and then to E. coli for 3 days. Results: Total hemocyte number tends to increase in all treated groups respect to G1. Cellular viability shows no variation between treatments. Hyalocyte proportion decreases in all treated groups, and it is negatively modulated by AZM in G6. Granulocyte proportions show the opposite trend to hyalocytes. Blust cells proportions increase significantly only in G5. Phagocytic activity in hyalocytes increases in all treated groups respect to G1, and it is significantly higher in G4 compared with the rest. Phagocytic activity in granulocytes decreases in G2-5 respect to G1, and it is positively modulated by AZM in G6. Acid phosphatase activity increases in G3-6 respect to G1-2. Alkaline phosphatase and β-glucuronidase activities increase in all treated groups respect to G1, and they are negatively modulated by AZM in G6, respect to G5. Lysosomal membrane stability decreases in all treated groups respect to G1, and it is positively modulated by AZM in G6 respect to G5. Bacteriolytic activity increases in G3, 5 and 6, while phenoloxidase activity decreases in G2, 4 and 6 compared with the other groups. Gill GST activity increases in all treatments respect to G1 and 2. Gill lipid peroxidation decreases in G4-6 respect to the others. Gill carboxyl esterase activity decreases in G4 and 6, respect to G2. Conclusion: Short-term exposure to AZM stimulates cellular response and promotes granulocyte phagocytic activity and lysosomal membrane stability, while alkaline phosphatase and β-glucuronidase activities are inhibited. AZM alters cellular population, decreasing hyalocyte proportions and increasing those of granulocytes. Bacteriolytic activity increases only in treatments with bacteria. Phenoloxidase activity decreases only in treatments with pesticide. In gills, AZM stimulates antioxidant defenses, while decreases carboxyl esterase activity.