title: Measurement of human cytochrome P4501A2 (CYP1A2) activity in vitro.
abstract: Cytochrome P4501A2 (CYP1A2) is responsible for the metabolism of a diverse range of clinically used drugs and dietary and environmental chemicals (including many procarcinogens). CYP1A2 expression is influenced by numerous factors, and hence wide interindividual variability is a characteristic feature of this enzyme in humans. Phenacetin represents a convenient probe for the assessment of human CYP1A2 activity in vitro (hepatic microsomes and recombinant enzyme). It is a relatively high-turnover substrate that forms only one major primary metabolite, the O-deethylated derivative acetaminophen. Acetaminophen formation in incubations of phenacetin with a CYP1A2 source is readily measured by HPLC with UV detection. The assay has a low requirement for human liver microsomes or recombinant enzyme, and is both selective and sensitive without the requirement for a solvent extraction step. Overall assay reproducibility is excellent, with coefficients of variation <4%.
authors.affiliation: Flinders Medical Centre and Flinders University School of Medicine, Bedford Park, Australia.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Polasek
authors.forename: David J
authors.initials: DJ
authors.lastname: Elliot
authors.forename: John O
authors.initials: JO
authors.lastname: Miners
mesh_terms: D000082:Acetaminophen / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D019388:Cytochrome P-450 CYP1A2 / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D000082:Acetaminophen; D019388:Cytochrome P-450 CYP1A2