CONICET | Buscador de Institutos y Recursos Humanos

Fipronil (Fp) is a current use pesticide, highly toxic with potential nocive effects onaquatic organisms. Biomarkers responses are frequently used to detectthese effects in fish either on laboratory exposure or in situ assessments.In ex vivo experimental models, the use of gills is justified since it is thefirst organ in contact with environmental pollutants. Biomarkersresponses promoted by two sublethal concentrations of Fp wereevaluated in Cyphocharax voga after a branchial ex vivo exposuremodel. After sacrificing the fish (n=4), branchial arches were dissectedand randomly assigned to four treatment groups: saline solution (Ctrl);methanol in saline solution (CtrlSv); and two nominal concentrations ofFp (9 µg/L, C1 and 100 µg/L, C2) prepared from a stock solution onmethanol. Gills remained submerged in the solutions under continuousagitation for 1h at 25°C in glass containers. Levels of Fp were alsoanalyzed with liquid-liquid extaction and GC-ECD. After incubationperiod, enzymatic activities of superoxide dismutase (SOD), antioxidantcapacity against peroxyl radicals (ACAP), lipid peroxidation levels byTBARS and reduced glutathione levels (GSH) were evaluated.Differences between groups were analyzed by one way ANOVA (p<0.05) and Tukey?s multiple comparisons. No significant differencesbetween the parameters of Ctrl and CtrlSv were detected. Gills exposureto C1 concentration promoted an increase (15%) in SOD activity.Furthermore, a significant increase (40%) in TBARS levels was detectedin C1 group respect to Ctrl. Exposition to C2 concentration promoted adecrease (38%) in GSH levels. No significant differences were observedin total antioxidant capacity (ACAP). These results indicate that theassayed concentrations of Fp proved to be an inducer of oxidative stressin gills. Enzymatic and non-enzymatic activities were not enough toprevent oxidative damage to lipid levels