RESUMO
Bluegills (Lepomis macrochirus) were exposed to two sublethal concentrations of carbofuran, a carbamate insecticide, and fenvalerate, a synthetic pyrethroid insecticide, in continuous flow bioassay systems for 30 days. Adenylate parameters (ATP concentration, total adenylates concentration, and adenylate energy charge) were monitored in gill, liver, muscle, and stomach tissues. There were significant decreases in adenylate energy charge of gill and stomach tissue relative to initial values after 10 days of exposure to 30 micrograms/L carbofuran. There was also a significant decline in adenylate energy charge in gills of fish exposed to 0.2 micrograms/L fenvalerate relative to initial values. These values returned to normal by the end of the experiment. The biological significance of these changes is uncertain. Adenylate parameters may not be sufficiently sensitive to reflect sublethal effects of pesticides which affect the nervous system of fishes.
Assuntos
Carbofurano/toxicidade , Inseticidas/toxicidade , Piretrinas/toxicidade , Poluentes Químicos da Água/toxicidade , Monofosfato de Adenosina/análise , Trifosfato de Adenosina/análise , Animais , Relação Dose-Resposta a Droga , Metabolismo Energético/efeitos dos fármacos , Mucosa Gástrica/metabolismo , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Músculos/efeitos dos fármacos , Músculos/metabolismo , Nitrilas , Perciformes , Estômago/efeitos dos fármacosAssuntos
Arocloros/farmacologia , Peixes-Gato/metabolismo , Ictaluridae/metabolismo , Metilcolantreno/farmacologia , Microssomos Hepáticos/metabolismo , Oxazinas/metabolismo , Fenobarbital/farmacologia , Bifenilos Policlorados/farmacologia , Animais , Sistema Enzimático do Citocromo P-450 , Remoção de Radical Alquila , Oxigenases/análise , Especificidade por SubstratoRESUMO
Bluegill (Lepomis macrochirus R.) were acclimated to 12, 22 or 32 degrees C for 5 or 14 days. Liver weight to body weight ratio and the rate of metabolism of benzo[alpha]pyrene by liver microsomes varied inversely with the acclimation temperature of the fish. Concentration of microsomal cytochrome P-450, as determined by CO-difference binding spectra, was not significantly affected by acclimation temperature. There were no qualitative or quantitative differences in the electrophoretic patterns of proteins with molecular weights similar to those reported for cytochrome P-450. There were no shifts in the temperature optima of the microsomal benzo[alpha]pyrene hydroxylase activity.
Assuntos
Aclimatação , Sistema Enzimático do Citocromo P-450/metabolismo , Peixes/fisiologia , Microssomos Hepáticos/enzimologia , Oxigenases de Função Mista/metabolismo , Animais , Benzopireno Hidroxilase/metabolismo , Peso Corporal , Fígado/anatomia & histologia , Tamanho do Órgão , Temperatura , TermodinâmicaRESUMO
The effects of temperature acclimation at 10, 20 and 30 degrees C on the concentration and activity of the mixed function oxidase system in bluegill are as follows. Liver weight/body weight varied inversely with temperature. Significant (P less than 0.05) differences in concentration of cytochrome P-450 of hepatic microsomes were seen and varied inversely with temperature. Benzo(a)pyrene hydroxylase activity tested in vitro at incubation temperatures of 10, 20 and 30 degrees C showed significant differences in Km, but no differences in Vmax. SDS polyacrylamide gel electrophoresis revealed some quantitative differences in cytochrome P-450 isozymes between groups.
