Metabolism of benzo(a)pyrene by cytochrome P-450 in transformable and nontransformable C3H mouse fibroblasts

Journal Article · Mon Jun 25 00:00:00 EDT 1979 · J. Biol. Chem.; (United States)

OSTI ID:5098062

Gehyly, E B ^[1]; Fahl, W E; Jefcoate, C R; Heidelberger, C

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1. Univ. of Southern California, Los Angeles

The microsomal metabolism of benzo(a)pyrene and its enhancement by inducers of aryl hywdrocarbon hydroxylase were studied in three C3H mouse fibroblast cell lines and in C3H mouse liver and lung. The cell lines examined included C3H/10T 1/2 CL8, a line that can be transformed by treatment with benzo(a)pyrene; CVP3SC6, a line which cannot be transformed by treatment with benzo(a)pyrene; and C3H/10T 1/2 CL16, a transformed cell line derived from 3-methylcholanthrene-treated C3H/10T 1/2 CL8 cells. Of four polycyclic hydrocarbons examined, benz(a)anthracene was found to be the most effective inducer of aryl hydrocarbon hydroxylase activity, while 3-methylcholanthrene did not induce. The extent of this induction in all three cell lines was dependent upon the time after seeding that the inducer was added. The C3H/10T 1/2 CL8 cells were induced by benz(a)anthracene to a greater extent than the other two cell lines. The high pressure liquid chromatographic profile of benzo(a)pyrene metabolites was qualitatively identical for microsomes from all three cell lines and differed from the metabolism by liver and lung microsomes in that the cells did not produce detectable levels of benzo(a)pyrene-4,5-hydrodiol. The reduced CO cytochrome P-450 difference spectra of control and induced microsomes from all three cell lines showed a characteristic shift to shorter wavelengths after induction with benz(a)anthracene. The specific activity of cytochrome P-450 in the cell microsomes closely paralled the benzo(a)pyrene metabolizing activity as measured both by the aryl hydrocarbon hydroxylase and high pressure liquid chromatography assays.

• OSTI ID: 5098062
• Journal Information: J. Biol. Chem.; (United States), Vol. 254:12
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
59 BASIC BIOLOGICAL SCIENCES
BENZOPYRENE
METABOLISM
HYDROXYLASE
ENZYME ACTIVITY
CYTOCHROMES
FIBROBLASTS
LIQUID COLUMN CHROMATOGRAPHY
LIVER
LUNGS
METABOLITES
MICE
ANIMAL CELLS
ANIMALS
AROMATICS
BODY
CHROMATOGRAPHY
CONDENSED AROMATICS
CONNECTIVE TISSUE CELLS
DIGESTIVE SYSTEM
ENZYMES
GLANDS
HYDROCARBONS
MAMMALS
ORGANIC COMPOUNDS
ORGANS
OXIDOREDUCTASES
PIGMENTS
RESPIRATORY SYSTEM
RODENTS
SEPARATION PROCESSES
SOMATIC CELLS
VERTEBRATES
560301* - Chemicals Metabolism & Toxicology- Cells- (-1987)
560305 - Chemicals Metabolism & Toxicology- Vertebrates- (-1987)
550200 - Biochemistry