title: Alteration of rat liver microsomal monooxygenase activities by gasoline treatment.
abstract: Previous work has shown an increase in rat liver enzyme activities after chronic exposure to gasoline vapor. In the present study, male Sprague-Dawley rats were pretreated with unleaded gasoline at 1 and 5 ml/kg, i.p., and selected hepatic microsomal monooxygenase activities were determined at 18, 48, and 72 h. At 18 h, moderate increases were observed in P450 content (1.3-fold), cytochrome c-reductase activity (1.25-fold), and in N-nitrosodimethylamine demethylation rate (1.25- to 1.6-fold). Pentoxyresorufin dealkylase activity (an activity displayed primarily by P450IIB1) was significantly elevated at 18 and 48 h (30- to 60-fold), and ethoxyresorufin dealkylase activity (an activity displayed by P450 IA1) was elevated (2- to 4-fold). Immunoblot analysis revealed no change in P450IIE1 at these time points, but an elevation in P450IIB1 in agreement with the pentoxyresorufin dealkylase activity measurements.
authors.affiliation: Department of Chemical Biology and Pharmacognosy, College of Pharmacy, Rutgers University, Piscataway, NJ 08855.
authors.forename: J F
authors.initials: JF
authors.lastname: Brady
authors.forename: F
authors.initials: F
authors.lastname: Xiao
authors.forename: J M
authors.initials: JM
authors.lastname: Gapac
authors.forename: S M
authors.initials: SM
authors.lastname: Ning
authors.forename: C S
authors.initials: CS
authors.lastname: Yang
mesh_terms: D000818:Animals; D019363:Cytochrome P-450 CYP1A1; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis; D005742:Gasoline / Q000633:toxicity*; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects* / Q000201:enzymology; D009245:NADH Dehydrogenase / Q000032:analysis; D010088:Oxidoreductases / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D005742:Gasoline; D003577:Cytochrome P-450 Enzyme System; D010088:Oxidoreductases; D019363:Cytochrome P-450 CYP1A1; D009245:NADH Dehydrogenase