We have studied the mutant frequency in the human gene for hypoxanthine-guanine phosphoribosyl transferase (hprt) using the T-cell cloning assay, the aromatic DNA adduct level using the 32P-postlabelling assay, and related the levels of these biomarkers to the genotypes for glutathione transferase (GSTmu) and N-acetyltransferase (NAT2) in non-smoking bus maintenance workers exposed to diesel exhaust.
No difference in mutant frequency was observed between the 47 exposed (8.6X10-6, age range 27-65) and the 22 control individuals (8.4X10-6, age range 23-61), while the difference in adduct level (3.2 versus 2.3X10-8) was highly significant (P=0.0009).
Both mutant frequency and adduct level were highest in the 16 most heavily exposed workers.
Overall, a significant increase of mutant frequency was observed with adduct level (P=0.008) as well as with age (P<0.0001).
The age dependence was higher in the GSTM1-negative slow acetylators (3.1%/year) as compared to the three other genotype combinations (2.4-2.5%/year).
There was no significant difference in mutant frequency or in adduct level between the GSTMI-negative (49.3% of the population) and positive individuals, or between the slow (60.9% of the population) and rapid acetylators.
These results suggest a possible role of both GSTmu and NAT2 for individual susceptibility to carcinogen exposure.
Mots-clés Pascal : Mutation ponctuelle, Hypoxanthine phosphoribosyltransferase, Pentosyltransferases, Glycosyltransferases, Transferases, Enzyme, Fréquence, Exposition professionnelle, Maintenance, Autobus, Lymphocyte T, Clonage cellulaire, Homme, Adduit moléculaire, DNA, Génotype, Glutathione transferase, Toxicité, Mutagenèse, N-acetyltransferase
Mots-clés Pascal anglais : Point mutation, Hypoxanthine phosphoribosyltransferase, Pentosyltransferases, Glycosyltransferases, Transferases, Enzyme, Frequency, Occupational exposure, Maintenance, Bus, T-Lymphocyte, Cell cloning, Human, Molecular adduct, DNA, Genotype, Glutathione transferase, Toxicity, Mutagenesis
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 95-0485721
Code Inist : 002B03N. Création : 01/03/1996.