The influence of genetic polymorphisms on population variability in six xenobiotic-metabolizing enzymes

Ginsberg, G; Smolenski, S; Neafsey, P; Hattis, D; Walker, K; Guyton, KZ; Johns, DO; Sonawane, B

HERO ID

196821

Reference Type

Journal Article

Subtype

Review

Year

2009

Language

English

PMID

20183525

HERO ID 196821
Material Type Review
In Press No
Year 2009
Title The influence of genetic polymorphisms on population variability in six xenobiotic-metabolizing enzymes
Authors Ginsberg, G; Smolenski, S; Neafsey, P; Hattis, D; Walker, K; Guyton, KZ; Johns, DO; Sonawane, B
Journal Journal of Toxicology and Environmental Health, Part B: Critical Reviews
Volume 12
Issue 5
Page Numbers 307-333
Abstract This review provides variability statistics for polymorphic enzymes that are involved in the metabolism of xenobiotics. Six enzymes were evaluated: cytochrome P-450 (CYP) 2D6, CYP2E1, aldehyde dehydrogenase-2 (ALDH2), paraoxonase (PON1), glutathione transferases (GSTM1, GSTT1, and GSTP1), and N-acetyltransferases (NAT1 and NAT2). The polymorphisms were characterized with respect to (1) number and type of variants, (2) effects of polymorphisms on enzyme function, and (3) frequency of genotypes within specified human populations. This information was incorporated into Monte Carlo simulations to predict the population distribution and describe interindividual variability in enzyme activity. The results were assessed in terms of (1) role of these enzymes in toxicant activation and clearance, (2) molecular epidemiology evidence of health risk, and (3) comparing enzyme variability to that commonly assumed for pharmacokinetics. Overall, the Monte Carlo simulations indicated a large degree of interindividual variability in enzyme function, in some cases characterized by multimodal distributions. This study illustrates that polymorphic metabolizing systems are potentially important sources of pharmacokinetic variability, but there are a number of other factors including blood flow to liver and compensating pathways for clearance that affect how a specific polymorphism will alter internal dose and toxicity. This is best evaluated with the aid of physiologically based pharmacokinetic (PBPK) modeling. The population distribution of enzyme activity presented in this series of articles serves as inputs to such PBPK modeling analyses.
Doi 10.1080/10937400903158318
Pmid 20183525
Wosid WOS:000271375100001
Is Certified Translation No
Dupe Override No
Comments Journal: Journal of Toxicology and Environmental Health, Part B ISSN:
Is Public Yes
Language Text English