Hepatic ethoxyresorufin 0-de-ethylase (EROD) and benzo(a)pyrene hydroxylase (B(a)PH) activity in flounder Platichthys flesus increased along a pollution gradient in Langesundfjord, examined during the GEEP Workshop. EROD activity in fish from a reference site was around 100 pm01 min-' mg microsomal protein-', increasing 5-fold at 2 moderately polluted sites and a further 2-fold at a more highly...

A microfluidic-based system was developed for the in situ monitoring of the 7-ethoxyresorufin O-dealkylation (EROD) activity of primary rat hepatocytes by measuring the fluorescent intensity of both cells and their surrounding media. The microfluidic chip was designed to allow the cell suspension and test reagent to be introduced in a layer-by-layer flow format, thereby resulting in a short mix...

In this study, we measured via surgical sampling hepatic EROD activity in yellow-legged gulls from oiled and unoiled colonies, 17 months after the Prestige oil spill. We also analyzed stable isotope composition in feathers of the biopsied gulls, in an attempt to monitor oil incorporation into marine food web. We found that yellow-legged gulls in oiled colonies were being exposed to remnant oil ...

Rutaecarpine, evodiamine, and dehydroevodiamine are quinazolinocarboline alkaloids isolated from a traditional Chinese medicine, Evodia rutaecarpa. The in vitro effects of these alkaloids on cytochrome P450 (P450)-catalyzed oxidations were studied using mouse and human liver microsomes. Among these alkaloids, rutaecarpine showed the most potent and selective inhibitory effect on CYP1A-catalyzed...

Xenobiotic metabolism is influenced by a variety of physiological and environmental factors including pregnancy and nutritional status of the individual. Pregnancy has generally been reported to cause a depression of hepatic monooxygenase activities. Low-protein diets and protein-energy malnutrition have also been associated with a reduced activity of monooxygenases in nonpregnant animals. We i...

Hydrophobic and volatile chemicals have proven to be difficult to dose in cell assays. Cosolvents are often needed to dissolve these chemicals in cell culture medium. Moreover, the free concentration of these chemicals in culture medium may diminish over time due to metabolism, evaporation, and nonspecific binding to well plate surfaces and serum constituents. The aim of this study was to devel...

Induction of the carcinogen-metabolizing enzyme cytochrome P4501A1 (CYP1A1) is a key step in the development of tobacco-related cancers. To determine if marijuana smoke activates CYP1A1, a murine hepatoma cell line expressing an inducible CYP1A1 gene (Hepa-1) was exposed in vitro to tar extracts prepared from either tobacco, marijuana, or placebo marijuana cigarettes. Marijuana tar induced high...

Human cytochrome P450 (CYP) isoforms involved in amiodarone N-deethylation were identified, and the relative contributions of these CYP isoforms were evaluated in different human liver microsomes. The mean K(M) and V(max) values of amiodarone N-deethylation in microsomes from six human livers were 31.6 +/- 7.5 microM and 1.2 +/- 0.7 pmol/min/pmol of CYP, respectively. Ketoconazole and anti-CYP3...