Lung metabolism of benzo(a)pyrene in rats treated with p-xylene and/or ethanol

Journal Article · Wed Jan 01 04:00:00 EST 1986 · J. Toxicol. Environ. Health; (United States)

DOI:https://doi.org/10.1080/15287398609530866· OSTI ID:5114325

Roberts, A E; Bogdanffy, M S; Brown, D R; Schatz, R A

The metabolism of benzo(a)pyrene (BaP) may be altered by xenobiotic compounds. The effects of p-xylene and ethanol on the lung metabolism of BaP were studied. p-Xylene was administered by ip injection at doses ranging from 0.1 to 1.0 g/kg (1:1 in soybean oil). Ethanol was administered po at 5 g/kg (40% w/v). Rats given p-xylene, ethanol, or p-xylene and ethanol were sacrificed 1 h after treatment. Additional time points of 15 min, 30 min, 4 h, and 24 h after p-xylene (1 g/kg) were examined. 3-Hydroxy-BaP (3-OH) formation was measured fluorometrically as aryl hydrocarbon hydroxylase activity (AHH) in lung microsomes. p-Xylene (1 g/kg) inhibited the formation of 3-OH BaP 40% at 15 min, 27% at 30 min, 43% at 1 h, and 39% at 4 h after treatment. Inhibition of AHH activity was still present 24 h after dosing (41%). AHH activity was inhibited 27% and 46% at 0.5 mg/kg and 1.0 mg/kg p-xylene (1 h), respectively, while the lowest dose (0.1 mg/kg) did not change activity. Analysis of the major metabolites of BaP by high-performance liquid chromatography (HPLC) demonstrated that the formation of 3-OH and 4,5-diol BaP were inhibited 32% and 50%, respectively, in lung microsomes prepared 24 h after a single injection of p-xylene (1 g/kg). None of the other metabolites analyzed were changed by p-xylene. Ethanol had no effect on 3-OH BaP formation during a 1-h treatment. A combined dose of ethanol and p-xylene moderately inhibited 3-OH BaP formation. These findings indicate that BaP detoxification (i.e., 3-OH formation) in rat lung is selectively inhibited by p-xylene but not ethanol. Ethanol appears to modify the inhibitory effect of p-xylene.

• Research Organization: Northeastern Univ., Boston, MA
• OSTI ID: 5114325
• Journal Information: J. Toxicol. Environ. Health; (United States), Journal Name: J. Toxicol. Environ. Health; (United States) Vol. 18:2; ISSN JTEHD
• Country of Publication: United States
• Language: English

Related Subjects

560305* -- Chemicals Metabolism & Toxicology-- Vertebrates-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALCOHOLS
ALKYLATED AROMATICS
ANIMALS
AROMATICS
ARYL 4-MONOOXYGENASE
BENZOPYRENE
BODY
CELL CONSTITUENTS
CONDENSED AROMATICS
DATA
DETOXIFICATION
ENZYME ACTIVITY
ENZYMES
ETHANOL
EXPERIMENTAL DATA
HYDROCARBONS
HYDROXY COMPOUNDS
HYDROXYLASES
INFORMATION
LUNGS
MAMMALS
METABOLISM
METABOLITES
MICROSOMES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANOIDS
ORGANS
OXIDOREDUCTASES
RATS
RESPIRATORY SYSTEM
RESPONSE MODIFYING FACTORS
RODENTS
VERTEBRATES
XYLENES