Concentrations of mercury that show acute and subacute toxicity in freshwater teleost (Ictalurus melas R.) have been determined during static experiments in aquaria. The LC50 at 96 h was found to be 0.57 mg/l Hg2+. Thus, catfish were exposed to selected subacute concentrations of Hg2+ (0.1, 0.2 and 0.4 mg/l) for 96 h and tissues were analyzed for metal accumulation. Gills, kidneys, liver and muscle were the tissues in which the mercury was stored in a dose-dependent manner. Biochemical responses of glutathione and several glutathione-dependent enzymes were evaluated in the liver of catfish after laboratory exposure to subacute concentrations of mercury during the static short-term experiment. Glutathione levels increased, while the hepatic specific activities of glyoxalase I, glyoxalase II, glutathione peroxidases (either selenium-dependent or selenium-independent enzymes) and glutatione S-transferases decreased. Glutathione reductase did not show significant variation in activity. The selected biochemical parameters are sensitive to assess the toxic effects of mercury in catfish exposed to subacute mercury concentrations.
Effects of mercury on glutathione and glutathione-dependent enzymes in catfish (Ictalurus melas R.)
ELIA, Antonia Concetta
;DOERR, Ambrosius J. Martin;TATICCHI, Maria Illuminata;
2000
Abstract
Concentrations of mercury that show acute and subacute toxicity in freshwater teleost (Ictalurus melas R.) have been determined during static experiments in aquaria. The LC50 at 96 h was found to be 0.57 mg/l Hg2+. Thus, catfish were exposed to selected subacute concentrations of Hg2+ (0.1, 0.2 and 0.4 mg/l) for 96 h and tissues were analyzed for metal accumulation. Gills, kidneys, liver and muscle were the tissues in which the mercury was stored in a dose-dependent manner. Biochemical responses of glutathione and several glutathione-dependent enzymes were evaluated in the liver of catfish after laboratory exposure to subacute concentrations of mercury during the static short-term experiment. Glutathione levels increased, while the hepatic specific activities of glyoxalase I, glyoxalase II, glutathione peroxidases (either selenium-dependent or selenium-independent enzymes) and glutatione S-transferases decreased. Glutathione reductase did not show significant variation in activity. The selected biochemical parameters are sensitive to assess the toxic effects of mercury in catfish exposed to subacute mercury concentrations.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
