Interindividual variations in human liver cytochrome P-450 enzymes involved in the oxidation of drugs, carcinogens and toxic chemicals: studies with liver microsomes of 30 Japanese and 30 Caucasians.
- T. Shimada, H. Yamazaki, M. Mimura, Y. Inui, F. Guengerich
- Medicine, BiologyJournal of Pharmacology and Experimental…
- 1 July 1994
The results presented in this study provide useful information for the study of drug biotransformation in humans and for the basis of drug toxicities, carcinogenesis and teratogenesis.
Activation of chemically diverse procarcinogens by human cytochrome P-450 1B1.
The selectivity of this enzyme in the activation of a variety of environmental carcinogens and mutagens in Salmonella typhimurium TA1535/pSK1002 or NM2009 tester strains was examined using the SOS response as an end point of DNA damage.
Xenobiotic-metabolizing enzymes involved in activation and detoxification of carcinogenic polycyclic aromatic hydrocarbons.
- T. Shimada
- Biology, ChemistryDrug Metabolism and Pharmacokinetics
Inter-individual differences exist in levels of expression and catalytic activities of a variety of enzymes that activate and/or detoxify PAHs in various organs of humans and these phenomena are thought to be critical in understanding the basis of individual differences in response toPAHs.
Metabolic activation of polycyclic aromatic hydrocarbons to carcinogens by cytochromes P450 1A1 and1B1
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitously distributed environmental chemicals. PAHs acquire carcinogenicity only after they have been activated by xenobiotic‐metabolizing enzymes to…
Oxidation of toxic and carcinogenic chemicals by human cytochrome P-450 enzymes.
Roles of NADPH-P450 reductase and apo- and holo-cytochrome b5 on xenobiotic oxidations catalyzed by 12 recombinant human cytochrome P450s expressed in membranes of Escherichia coli.
- H. Yamazaki, Mami Nakamura, T. Yokoi
- Biology, ChemistryProtein Expression and Purification
- 1 April 2002
P450/NPR membrane systems containing b5 are useful models for prediction of the rates for liver microsomal P450-dependent drug oxidations and may be different in some human CYP2 family enzymes, possibly due to a conformational role of b5.
Selectivity of polycyclic inhibitors for human cytochrome P450s 1A1, 1A2, and 1B1.
- T. Shimada, H. Yamazaki, M. Foroozesh, N. Hopkins, W. Alworth, F. Guengerich
- Chemistry, BiologyChemical Research in Toxicology
- 5 August 1998
Several polycyclic hydrocarbons and their oxidation products are very inhibitory with respect to human P450s 1A1, 1A2, and 1B1; (ii) of these inhibitors only some are mechanism-based inactivators; and (iii) some of the inhibitors are potentially useful for distinguishing between human P 450s 2A1 and 2B1.
Progesterone and testosterone hydroxylation by cytochromes P450 2C19, 2C9, and 3A4 in human liver microsomes.
The results suggest that CYP2C19 plays important roles in the oxidation of progesterone and testosterone in human liver microsomes, although the physiological significance of these metabolic pathways remains unclear.
Activation of procarcinogens by human cytochrome P450 enzymes.