RESUMO
1. Ringed seals were exposed experimentally to oil contamination, by feeding of a [14C]naphthalene marked crude oil in fish for up to 4 days at a rate of 5 ml/day. 2. Mixed function oxygenase (MFO) activity, measured as aryl hydrocarbon hydroxylase in liver and kidney, was found to be induced, in particular in kidney tissue where the activity increased 3-fold. 3. MFO induction correlated with a high degree of conversion of crude oil hydrocarbons to water-soluble metabolites. Most of the radioactivity was found in the polar fraction of plasma and urine. 4. Plasma cortisol levels were somewhat elevated by captive holding, and increased markedly after oil-exposure. Cortisol half-life decreased after oil exposure from 1 3/4 to 1 hr.
Assuntos
Caniformia/metabolismo , Óleos Combustíveis/toxicidade , Hidrocortisona/sangue , Oxigenases de Função Mista/metabolismo , Oxirredutases/metabolismo , Petróleo/toxicidade , Focas Verdadeiras/metabolismo , Animais , Hidrocarboneto de Aril Hidroxilases/metabolismo , Dieta , Rim/enzimologia , Fígado/enzimologiaRESUMO
American eels, Anguilla rostrata, were exposed to crude oil by ingestion of a 10, 100, or 500 microliters/kg fish dose per day for five days. Depuration was followed for an additional twelve days. All oil doses caused an induction of hepatic microsomal enzymes, maximally by three days of exposure. Benzo(a)pyrene hydroxylase (BaPH) showed a dose related response, with greater induction at 100 microliters/kg than at the other doses. The highest dose was hepatotoxic. Cytochrome P-450 induction was dose independent, and remained induced maximally for the entire experimental period, in contrast to BaPH which declined in activity. Reaction optimum for BaPH was at pH 7.5 and 27 degrees C. A study of tissue distribution showed the liver to account for nearly all BaPH activity. A significant increase in the protein content of the hepatic postmitochondrial fraction of oil-exposed fish was also observed.
Assuntos
Enguias/metabolismo , Oxigenases de Função Mista/biossíntese , Oxirredutases/biossíntese , Petróleo/toxicidade , Animais , Hidrocarboneto de Aril Hidroxilases/metabolismo , Benzopireno Hidroxilase/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Indução Enzimática/efeitos dos fármacos , Fígado/enzimologia , Distribuição TecidualAssuntos
Aldosterona/sangue , Caniformia/fisiologia , Hidrocortisona/sangue , Focas Verdadeiras/fisiologia , Tiroxina/sangue , Tri-Iodotironina/sangue , Animais , Contagem de Eritrócitos , Feminino , Hematócrito , Masculino , Leite/análise , Focas Verdadeiras/crescimento & desenvolvimento , Sódio/sangue , Tiroxina/análise , Tri-Iodotironina/análiseRESUMO
Plasma and tissue levels of dietary radiotracer-labeled tocopherols were examined in the harp seal, Phoca groenlandica. The d-alpha form showed much higher plasma maxima and retention than d,l-gamma-tocopherol. Concentration peaks occurred somewhat later but were greater when the vitamin was fed with Tween 80 than with herring and corn oil respectively. Greater plasma levels occurred with the use of herring oil as compared with corn oil. Seals previously maintained on a vitamin E deficient diet showed greater plasma maxima than seals not so deprived. Plasma and tissues generally showed maximum levels within 24 h postingestion. Tissue levels of labelled dietary alpha-tocopherol were examined by biopsy and postmortem studies in selected tissues of vitamin E deprived seals.
