RESUMO
Sublethal effects of chlorpyrifos (CPF) and monocrotophos (MCP) on fish biochemical constituents were investigated along with the assessment of recovery response after cessation of intoxication. The fish, Clarias batrachus were exposed to 1.656 mg(-l) and 2.114 mg(-l) of CPF and MCP for 28 days. After 28 days, they were released in freshwater and allowed to recover for 21 days. The CPF exposure resulted in the decrease of carbohydrate and glycogen content, whereas MCP intoxication caused mixed response. Pyruvate and lactate contents were altered under the stress of CPF and MCP. Recovery of these alterations was observed after the cessation of toxicity. Exposure of C. batrachus to CPF and MCP resulted in decreased activity of lactate dehydrogenase in the kidney, liver and muscle but its activity increased in the gills. The CPF caused inhibition of succinate dehydrogenase enzyme in all tissues. Induction in the activity of malate dehydrogenase was caused by both insecticides. Glycogen phosphorylase a was induced in all tissues, whereas glycogen phosphorylase ab showed both induction and inhibition. Of the two insecticides, CPF was more toxic and the recovery response was less. These results are important in the assessment of the risk caused by organophosphate insecticides on nontarget organisms, especially the food fish.
Assuntos
Peixes-Gato/metabolismo , Clorpirifos/toxicidade , Inseticidas/toxicidade , Monocrotofós/toxicidade , Animais , Metabolismo dos Carboidratos/efeitos dos fármacos , Estudos de Casos e Controles , Clorpirifos/farmacocinética , Brânquias/química , Glicogênio/metabolismo , Glicogênio Fosforilase/metabolismo , Inativação Metabólica , Inseticidas/farmacocinética , Rim/química , Rim/efeitos dos fármacos , Ácido Láctico/metabolismo , Fígado/química , Fígado/efeitos dos fármacos , Fígado/metabolismo , Monocrotofós/farmacocinética , Músculos/química , Oxirredutases/metabolismo , Medição de Risco , Distribuição TecidualRESUMO
The effects of a sublethal concentration (7.66 mg/L) of carbofuran, were assessed on Clarias batrachus. The fish were exposed to 7.66 mg of carbofuran/L for 6 days. After 6 days, fish were released into carbofuran-free water in order to study the recovery pattern. Proteins were decreased in gill and kidney and recovery was greater in gill than in kidney. Total amino acids were increased in both tissues. Ammonia level declined in gill and enhanced in kidney throughout the study period. The activities of all enzymes measured were induced in both tissues, except for aspartate aminotransaminase, which was inhibited in gill tissues.