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Comparison of CYP1A2 and NAT2 phenotypes between black and white smokers

Muscat, Joshua E.; Pittman, Brian; Kleinman, Wayne; Lazarus, Philip; Stellman, Steven D.; Richie, John P.

Date Published:





Extra Links:

October 1, 2008


PMID: 18703023 PMCID: PMC2597011


The lower incidence rate of transitional cell carcinoma of the urinary bladder in blacks than in whites may be due to racial differences in the catalytic activity of enzymes that metabolize carcinogenic arylamines in tobacco smoke. To examine this, we compared cytochrome P4501A2 (CYP1A2) and N-acetyltransferase-2 activities (NAT2) in black and white smokers using urinary caffeine metabolites as a probe for enzyme activity in a community-based study of 165 black and 183 white cigarette smokers. The paraxanthine (1,7-dimethylxanthine, 17X)/caffeine (trimethylxanthine, 137X) ratio or [17X+1,7-dimethyluric acid (17U)]/137X ratio was used as an indicator of CYP1A2 activity. The 5-acetyl-amino-6-formylamino-3-methyluracil (AFMU)/1-methylxanthine (1X) ratio indicated NAT2 activity. The odds ratio for the slow NAT2 phenotype associated with black race was 0.4; 95% confidence intervals 0.2-0.7. The putative combined low risk phenotype (slow CYP1A2/rapid NAT2) was more common in blacks than in whites (25% vs. 15%, P

Automatic Tags

Female; Humans; Male; Adult; Smoking; Creatinine; Phenotype; European Continental Ancestry Group; Glutathione Transferase; African Continental Ancestry Group; Caffeine; Cytochrome P-450 CYP1A2; New York; Arylamine N-Acetyltransferase; Cotinine; Polymorphism, Restriction Fragment Length

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