Cytochrome P450 is a superfamily of membrane-bound hemoprotein that gets involved with the degradation of xenobiotics and internal metabolites. Accumulated body of evidence indicates that phospholipids play a crucial role in determining the enzymatic activity of cytochrome P450 in the microenvironment by modulating its structure during detoxification; however, the structure-function relationshi...

Extracts from semi-permeable membrane devices (SPMDs) deployed on beaches in Prince William Sound (PWS), Alaska, were used to evaluate if complex contaminant mixtures from different sources can be distinguished by the resulting cytochrome P450 1A (CYP1A) activity in exposed test animals. Deployment sites included canneries, salmon hatcheries, and beaches where lingering oil remains from dischar...

In order to investigate cell-specific differences in the response of in vitro models to environmental toxicants, we compared the capacity of nine polycyclic aromatic hydrocarbons (PAHs) to induce cytochrome P4501A (CYPIA) in primary rainbow trout (Oncorhynchus mykiss) hepatocytes and a rainbow trout liver cell line, RTL-W1. Induction of CYPIA was estimated from the catalytic activity of 7-ethox...

Induction of cytochrome P4501A CYP1A in cultured cells can be used to determine the induction potencies of xenobiotics or complex environmental samples. This report describes the development of an enzyme linked immunosorbent assay ELISA for measurement of CYP1A expression in primary cultures of rainbow trout Oncorhynchus mykiss hepatocytes. Juvenile rainbow trout were injected with naphthoflavo...

The metabolic activation of dimethylnitrosamine (DMN) to mutagenic and/or cytotoxic intermediates in vitro has been characterized and the relationship between DMN demethylase and ethoxyresorufin-O-deethylase (EROD) or ethylmorphine-N-demethylase (EMND) has been evaluated. A mammalian assay system which uses the postmitochondrial supernatant (S-15 fraction) prepared from a rat liver homogenate a...

Despite being considered friendlier to the environment, biodiesel fuel can be harmful to aquatic organisms, especially when combined with petroleum diesel fuel. In this work we evaluated the effects of mineral diesel fuel containing increasing concentrations of biodiesel (5% and 20%, namely B5 and B20) and pure biodiesel (B100), at concentrations of 0.001 and 0.01mLL(-1), after 15 days of expos...

The effect of cytochrome P4501A (CYP1A) induction on cell-specific benzo[a]pyrene (BaP) adduct formation was studied in rainbow trout (Oncorhynchus mykiss) gills. Fish preexposed to beta-naphthoflavone (betaNF) or caged in a polluted river were exposed to waterborne 3H-benzo[a]pyrene (3H-BaP). The 3H-benzo[a]pyrene adducts in the gill filaments were localized by autoradiography and CYP1A protei...

Uroporphyrinogen is an intermediate of the heme biosynthetic pathway. The oxidation of uroporphyrinogen to uroporphyrin (UROX) has been demonstrated to be catalyzed by mammalian CYP1A2. This reaction has an important role in uroporphyria caused by halogenated aromatic compounds. Two CYP enzymes induced by Ah receptor ligands were purified recently from chick embryo liver. One, designated CYP1A5...

The effects of Atrazine, an herbicide used worldwide and considered as a potential contaminant in aquatic environments, were assessed on the Neotropical fish Prochilodus lineatus acutely (24 and 48 h) exposed to 2 or 10 μg L(-1) of atrazine by using a set of biochemical and genetic biomarkers. The following parameters were measured in the liver: activity of the biotransformation enzymes ethoxyr...

Oil spills occur commonly, and chemical compounds originating from oil spills are widespread in the aquatic environment. In order to monitor effects of a bunker oil spill on the aquatic environment, biomarker responses were measured in eelpout (Zoarces viviparus) sampled along a gradient in Göteborg harbor where the oil spill occurred and at a reference site, 2 weeks after the oil spill. Eelpou...