In vitro effects of straight-chain alkanes (n-hexane through n-dodecane) on rat liver and lung cytochrome P-450

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

DOI:https://doi.org/10.1080/15287398609530881· OSTI ID:5088704

Rabovsky, J; Judy, D J; Pailes, W H

To evaluate the effect of straight-chain alkanes on normal detoxication reactions a study was made of the in vitro effect of the homologous series n-hexane through n-dodecane on two cytochrome P-450 (EC 1.14 14.1) enzyme activities. Benzo(a)pyrene hydroxylase (BaPOHase) and 7-ethyoxycoumarin deethylase activities were measured in liver and lung microsomes of control and ..beta..-naphthoflavone-treated rats. In the presence of 2 mM n-hexane through n-dodecane, liver BaPOHase activity decreased from 67% of control with n-dodecane to 21% of control with octane. Lung benzo(a)pyrene hydroxylase was insensitive to all tested alkanes at 2 mM. In the presence of 2 mM alkanes, liver 7-ethoxycoumarin deethylase activity decreased from 73% of control with n-octane to 28% with n-octane. Lung 7-ethoxycoumarin deethylase was also sensitive to the alkane series. In the presence of 2 mM alkane the greatest effect was obtained with n-octane and represented a 56% loss in activity. Alkane concentration-dependent measurements showed 0.02-0.20 mM as the sensitive region of the curve for n-octane with maximal loss of activity achieved at 0.20 mM. Liver ethyoxycoumarin deethylase activity from ..beta..-naphthoflavone-treated rats was less sensitive towards the reactive alkane, n-octane, than the activity from control rats: Double-reciprocal-plot analysis revealed the maximal velocity (V/sub max/) was decreased in the presence of 0.2 mM n-octane. Hence this hydrocarbon did not exert its effect solely as an alternate substrate.

• Research Organization: National Institute for Occupational Safety and Health, Morgantown, WV
• OSTI ID: 5088704
• Journal Information: J. Toxicol. Environ. Health; (United States), Journal Name: J. Toxicol. Environ. Health; (United States) Vol. 18:3; 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.
ALKANES
ANIMALS
BODY
CELL CONSTITUENTS
COMPARATIVE EVALUATIONS
CYTOCHROME OXIDASE
DATA
DETOXIFICATION
DIGESTIVE SYSTEM
DOSE-RESPONSE RELATIONSHIPS
ENZYME ACTIVITY
ENZYMES
EXPERIMENTAL DATA
GLANDS
HAEM DEHYDROGENASES
HYDROCARBONS
INFORMATION
LIVER
LUNGS
MAMMALS
MICROSOMES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANOIDS
ORGANS
OXIDOREDUCTASES
RATS
RESPIRATORY SYSTEM
RODENTS
STRUCTURE-ACTIVITY RELATIONSHIPS
TOXICITY
VERTEBRATES