Metabolism of benzo(a)pyrene by duck liver microsomes
| Autor: | Subodh Kumar, Sangeet A. Honey, Harish C. Sikka, Adam T. Drahushuk, James R. Olson, Patrick O’Keefe |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Pharmacology
Anas biology Cytochrome Immunology Molecular Conformation Metabolism biology.organism_classification Dihydroxydihydrobenzopyrenes chemistry.chemical_compound Ducks Common merganser Biochemistry Benzo(a)pyrene chemistry Enzyme Induction Carcinogens Cytochrome P-450 CYP1A1 Microsomes Liver Microsome biology.protein Animals Pyrene Carcinogen |
| Zdroj: | Comparative Biochemistry and Physiology Part C: Pharmacology, Toxicology and Endocrinology. 126:285-292 |
| ISSN: | 0742-8413 |
| Popis: | The metabolism of benzo(a)pyrene [BP], a model carcinogenic PAH, by hepatic microsomes of two duck species, mallard (Anas platyrhynchos) and common merganser (Mergus merganser americanus) collected from chemically-contaminated and relatively non-contaminated areas was investigated. The rate of metabolism of BP by liver microsomes of common merganser and mallard collected from polluted areas (2,650 +/- 310 and 2,200 +/- 310 pmol/min per mg microsomal protein, respectively) was significantly higher than that obtained with liver microsomes of the two species collected from non-polluted areas (334 +/- 33 and 231 +/- 30 pmol/min per mg microsomal protein, respectively). The level of cytochrome P-450 1A1 was significantly higher in the liver microsomes of both duck species from the polluted areas as compared to the ducks from the non-polluted areas. The major BP metabolites, including BP-9, 10-diol, BP-4, 5-diol, BP-7, 8-diol, BP-1, 6-dione, BP-3, 6-dione, BP-6, 12-dione, 9-hydroxy-BP and 3-hydroxy-BP, formed by liver microsomes of both duck species from polluted and non-polluted areas, were qualitatively similar. However, the patterns of these metabolites were considerably different from each other. Liver microsomes of ducks from the polluted areas produced a higher proportion of benzo-ring dihydrodiols than the liver microsomes of ducks from the non-polluted areas, which converted a greater proportion of BP to BP-phenols. The predominant enantiomer of BP-7,8-diol formed by hepatic microsomes of the two duck species had an (-)R,R absolute stereochemistry. The data suggest that duck and rat liver microsomal enzymes have different regioselectivity but similar stereoselectivity in the metabolism of BP. |
| Databáze: | OpenAIRE |
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