Tow major goals of drug metabolism studies ar to identify and characterize pathways of biotransformation that lead to toxic and active metabolites, and to utilize this information to therapeutic advantage. The research described in this proposal uses minor changes to the chemical structure of various drugs to alter their metabolism, and thereby modify their toxicity or therapeutic activity. Thus, the application is an extension of our previous work to elucidate molecular mechanisms of reactive. Thus, the application is an extension of our previous work to elucidate molecular mechanisms of reactive metabolite formation and disposition, to characterize mechanism of oxidative N-dealkylation, and to synthesize suicide inhibitors of aromatase.
The aims of the present project are: 1. To use dimethylated and regioisomeric analogs of the widely used analgesic and antipyretic, acetaminophen, to determien the role of oxidative stress and arylation of tissue proteins in hepatotoxicity caused by the drug. A combination of radiochemical and immunochemical techniques coupled with 2-D electrophoresis and enzyme activity assays will be used as tools to help dissect the mechanisms. 2. To characterize the metabolism and toxicity of R-(+)-pulegone and its proximate toxin, menthofuran, by modulation of thiol status and by oxygen-18 labeling techniques. 3. To determien the contribution of electronic and steric effects in cytochrome P-450-mediated carbinolamine formation form N- methylcarbazole by synthesizing and testing a series of dideuterated N-methylcarbazoles that either electronically or sterically modify the N-methyl group. 4. To determine the selectivity of thioandrogens for aromatase by investigating the effects of thiol group modification of androgens on cytochromes P-450 other than aromatase, and to investigate the molecular mechanism of inactivation of aromatase itself by the use of radiolabeled thioandrogens and sulfenic acid and/or peroxyandrogen metabolite probes. The overall project is expected to advance our knowledge of mechanisms of drug-induced cell death and mechanisms of metabolite formation, and may lead to drugs with enhanced therapeutic benefit.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM025418-13
Application #
3272988
Study Section
Toxicology Subcommittee 2 (TOX)
Project Start
1978-07-01
Project End
1994-03-31
Budget Start
1991-04-01
Budget End
1992-03-31
Support Year
13
Fiscal Year
1991
Total Cost
Indirect Cost
Name
University of Washington
Department
Type
Schools of Pharmacy
DUNS #
135646524
City
Seattle
State
WA
Country
United States
Zip Code
98195
Khojasteh, S Cyrus; Hartley, Dylan P; Ford, Kevin A et al. (2012) Characterization of rat liver proteins adducted by reactive metabolites of menthofuran. Chem Res Toxicol 25:2301-9
Ortiz de Montellano, Paul R; Nelson, Sidney D (2011) Rearrangement reactions catalyzed by cytochrome P450s. Arch Biochem Biophys 507:95-110
Khojasteh, S Cyrus; Oishi, Shimako; Nelson, Sidney D (2010) Metabolism and toxicity of menthofuran in rat liver slices and in rats. Chem Res Toxicol 23:1824-32
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Chen, W; Shockcor, J P; Tonge, R et al. (1999) Protein and nonprotein cysteinyl thiol modification by N-acetyl-p-benzoquinone imine via a novel ipso adduct. Biochemistry 38:8159-66

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