title: Smoking-reIated DNA adducts and genetic polymorphism for metabolic enzymes in human lymphocytes.
abstract: Abstract Smoking-related aromatic DNA adducts in lymphocytes were measured from smokers (n = 76), ex-smokers (n = 25) and non-smokers (n = 56) by the (32)P-postlabelling method, to clarify whether a genetic polymorphism for metabolic enzymes could explain the inter-individual variation of DNA adduct levels. Adduct levels were compared with respect to smoking status and polymorphic genotypes of cytochrome P4501A1 (CYP1A1) and glutathione S-transferase M1 (GTSM1). The mean adduct level (1.24 per 10(8) nucleotides) in smokers was significantly higher than that (0.85 per 10(8)) in non-smokers. Although we expected higher adduct levels in the CYP1A1 variant or GSTM1 null subjects, the adduct level in 'GSN1 nulls' was significantly lower than that in 'GSTM1 presents' among smokers. DNA adduct levels had significant positive correlations with smoking indices such as number of cigarettes or smoking years in all subjects. In smokers only, however, no correlation was found, because there were negative correlations between adduct levels and smoking dose in GSTM1 null genotypes. CYP1A1 genotypes had no effects on adduct levels.
authors.affiliation: Department of Community Health Science, Saga Medical School, Saga, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Ichiba
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: H
authors.initials: H
authors.lastname: Oishi
authors.forename: M
authors.initials: M
authors.lastname: Lyadomi
authors.forename: N
authors.initials: N
authors.lastname: Shono
authors.forename: K
authors.initials: K
authors.lastname: Tomokuni