Effects of polychlorinated biphenyls on porphyrin synthesis and cytochrome P-450 dependent monooxygenases in small intestine and liver of Japanese quail
The effects of acute exposure to polychlorinated biphenyls (PCBs) on porphyrin synthesis and cytochrome P-450-dependent monooxygenases in the small intestine and liver were studied in male Japanese quail. The birds were dosed orally with the PCB mixture, Aroclor 1242, or the individual PCB isomers, 2,4,2',4'-tetrachlorobiphenyl (2-TCB) and 3,4,3',4'-tetrachlorobiphenyl (3-TCB), and were killed 48 h later. All the PCB compounds caused a significant increase in porphyrin content and sigma-aminolevulinic acid synthetase (ALA-S) activity in the small intestine and liver. Increases in porphyrins were greater in the small intestine in the liver. However, a smaller increase in ALA-S activity occurred in the small intestine than in liver, suggesting that ALA-S induction is not a major mechanism for the increased porphyrin content of small intestine. All the test compounds significantly increased the cytochrome P-450 content of liver. In the small intestine, cytochrome P-450 content was increased by Aroclor 1242 and 2-TCB but not by 3-TCB. The activity of 7-ethoxyresorufin O-deethylase, however, was increased by all test compounds in both liver and small intestine. In contrast, there was a striking difference between small intestine and liver in the induction of 7-ethoxycoumarin O-deethylase (ECOD) activity by Aroclor 1242. In the liver, ECOD activity was unchanged or decreased, but in the small intestine, ECOD activity linearly with dose. No tissue difference in ECOD activity was observed after treatment with 2-TCB or 3-TCB.
- Research Organization:
- Oregon State Univ., Corvallis
- OSTI ID:
- 6694458
- Journal Information:
- J. Toxicol. Environ. Health; (United States), Vol. 20:1-2
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BIRDS
ENZYME ACTIVITY
CHLORINATED AROMATIC HYDROCARBONS
TOXICITY
OXIDOREDUCTASES
ENZYME INDUCTION
PORPHYRINS
METABOLISM
ACUTE EXPOSURE
CYTOCHROME OXIDASE
DOSE-RESPONSE RELATIONSHIPS
LIVER
ORAL ADMINISTRATION
SMALL INTESTINE
ANIMALS
AROMATICS
BODY
CARBOXYLIC ACIDS
DIGESTIVE SYSTEM
ENZYMES
GASTROINTESTINAL TRACT
GENE REGULATION
GLANDS
HAEM DEHYDROGENASES
HALOGENATED AROMATIC HYDROCARBONS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
INTESTINES
ORGANIC ACIDS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
VERTEBRATES
560300* - Chemicals Metabolism & Toxicology