Time-varying conjugation of 7,12-dimethylbenz[a]anthracene metabolites in rainbow trout (Oncorhynchus mykiss)

Abstract Sexually immature rainbow trout were dosed via gavage with 7,12-[ 14 C]dimethylbenz[ a ]anthracene (DMBA) in order to study hepatic metabolite formation over time and at single and multiple doses. β-Glucuronidase and aryl sulfatase hydrolyses of bile extracts and subsequent high-pressure liquid chromatography analysis demonstrated significant levels of sulfate conjugates formed after 12 hr of exposure to a single dose. By 72 hr, glucuronide conjugates had increased and after three doses of [ 14 C]DMBA, glucuronides exceeded the amount of sulfates by almost an order of magnitude. Of the metabolites that could be tentatively identified, the majority were oxidative derivatives of the aromatic rings 3-OH DMBA and 3,4- trans -OHDMBA, the latter of which is mutagenic and a precursor to the proposed ultimate carcinogen of DMBA.