OBJECTIVE To investigate the metabolites of polybrominated diphenyl ether 99 (BDE-99) and its related cytochrome P450s in an in vitro system. METHODS Rat primary hepatocytes were isolated and treated with BDE-99 for 24-72 h. Metabolites were then extracted from the hepatocytes and media, and detected by GC/MS. Several mRNAs of metabolic enzymes were also extracted from the same cells and the ...

Cytochrome P-450 was purified to apparent homogeneity from the brain microsomes of phenobarbital-treated rats. The specific content of the purified P-450 was 12.7 nmol/mg of protein. NADPH-cytochrome P-450 reductase (reductase) was also purified to apparent homogeneity from brain microsomes. The specific content was 34.7,mol of cytochrome c reduced/min per mg of protein. The reduced carbon mono...

A form of cytochrome P-450 catalyzing lanosterol 14a-demethylation (tentatively called ‘P’45014DMn) was purified from microsomes of semi-anaerobically grown cells of Saccharomyces cerevisiae to gel electrophoreitc homogeneity. An apparent monomeric M. = 58,000 was estimated for the purified cytochrome by sodium dodecyl sulfate-polyacrylamide g l electrophoresis. Both optical and EPR spectra of ...

By using 3-amino-1,2,4-triazole, an inhibitor of haem synthesis, and 2-allyl-2-isopropylacetamide, a drug that degrades the haem moiety of cytochrome P-450, the involvement of haem in cytochrome P-450 synthesis and assembly was investigated. Phenobarbital was used to stimulate apo-(cytochrome P-450) synthesis. Degradation of preformed cytochrome P-450 haem does not result in a concomitant relea...

Allylisopropylacetamide is shown to be a suicide substrate for the phenobarbital-inducible cytochromes P-450. In phenobarbital-induced rat liver microsomes about 70% of the cytochrome P-450-mediated N,N-dimethylaniline N-demethylase activity is sensitive to allylisopropylacetamide inactivation; the residual 30% of the N-demethylase activity is incapable of allylisopropylacetamide turnover and i...