Fish tolerance to organophosphate-induced oxidative stress is dependent on the glutathione metabolism and enhanced by N-acetylcysteine
Abstract Dichlorvos (2,2-dichlorovinyl dimethyl phosphate, DDVP) is an organophosphorus (OP) insecticide and acaricide extensively used to treat external parasitic infections of farmed fish. In previous studies we have demonstrated the importance of the glutathione (GSH) metabolism in the resistance of the European eel ( Anguilla anguilla L.) to thiocarbamate herbicides. The present work studied the effects of the antioxidant and glutathione pro-drug N -acetyl- l -cysteine (NAC) on the survival of a natural population of A. anguilla exposed to a lethal concentration of dichlorvos, focusing on the glutathione metabolism and the enzyme activities of acetylcholinesterase (AChE) and caspase-3 a…
Glutathione-dependent resistance of the European eel Anguilla anguilla to the herbicide molinate
Eels of species Anguilla anguilla were exposed to 5/4 LC50 (41.8 mg/l) of the herbicide molinate for 96 h in a time to death (TTD) test. Glutathione content (GSx, GSH, GSSG), glutathione reductase (GR) and gamma-glutamyl transpeptidase (gamma-GT) activities were determined in the liver and muscle tissues of dead and surviving (intoxicated) animals and compared to control values (non-exposed eels). TTD was positively correlated to hepatic GSH, GSH:GSSG ratio, hepatic and muscular GR, but negatively correlated to muscular GSH, which was severely depleted. Furthermore, glutathione and enzyme activities were intercorrelated, especially GSH and GR. These results indicate that eels which were abl…
Impaired glutathione redox status is associated with decreased survival in two organophosphate-poisoned marine bivalves
Biomonitoring organophosphate (OP) exposure in marine environments is generally achieved by the measurement of acetylcholinesterase activity in bivalves like mussels. However, there is evidence that indicates that oxidative stress may be implied in OP toxicity. The aim of this study was to evaluate the relationship between survival from the OP insecticide fenitrothion and glutathione levels in marine bivalves. Mussels (Mytilus galloprovincialis Lam.) and scallops (Flexopecten flexuosus Poli) were exposed, in a time to death test, to their LC85 of fenitrothion for 96 h. OP-poisoned mussels showed reduced (GSH) and oxidised (GSSG) glutathione depletion in the digestive gland, muscle and gills…
Increased recovery of brain acetylcholinesterase activity in dichlorvos-intoxicated European eels Anguilla anguilla by bath treatment with N-acetylcysteine
Organophosphate (OP) pesticides are widely used as antiparasitic chemicals in finfish aquaculture. However, current antidotes cannot be applied to treat intoxicated fish. We showed in previous studies the importance of glutathione (GSH) metabolism in pesticide resistance of the European eel Anguilla anguilla L. The present work studied the effects of the antioxidant and glutathione pro-drug N-acetyl-l-cysteine (NAC) on the recovery of European eels exposed for 96 h to a sublethal concentration (0.17 mg l^-1; 20% of its 96 h LC50) of the OP pesticide dichlorvos (2,2-dichlorovinyl dimethyl phosphate; DDVP). This insecticide and acaricide decreased muscular GSH content and increased oxidised g…