Abstract: Purpose : To investigate the effects of CYP1A1 and GSTM1 allelotypes on the in vivo micronucleus formation in human peripheral lymphocytes induced by smoking and drinking. Methods : The allelotypes of CYP1A1 and GSTM1 were detected by allele-specific (AS)- and multiplex differential (MD)-PCR respectively. Micronuclei were detected by the in vivo micronucleus test in human capillary blood lymphocytes. Results : It showed that cigarette smoking increased significantly MNF in lymphocvtes (0. 65 ‰, P < 0. 05) as compared with those of healthy non-smokers (0. 24 ‰) , heavy alcohol-drinking enhanced this effect (0. 89 ‰, P < 0. 01) ; smoking increased significantly MNF in lymphocytes from individuals with the genotype GSTM1 0/ 0 (0. 75 ‰, P < 0. 05) and induced the statistically marginal increase of MNF in lymphocytes of individuals with the genotype CYP1A1 Val/ Val and the susceptible combined genotypes CYP1A1 Val/ Val ·GSTM1 0/ 0 , CYP1A1Val/ Val·GSTM1 + ( + / + and + / 0) and CYP1A1 Val/ Ile·GSTM1 0/ 0 as compared wich those of individuals with the non-susceptible combined genotypes CYP1A1 Ile/ Ile·GSTM1 + , CYP1A1 Ile/ Ile·GSTM1 0/0 and CYP1A1 Ile/ Val ·GSTM1 + . Conclusion : Cigarette smoking induced the significant increase of MNF in lymphocytes of human peripheral blood , heavy alcohol drinking enhanced obviously the effect . The in vivo micronucleus formation induced by smoking and drinking had the close association wich CYP1A1 and GSTM1 allelotypes.

Key words: allelotypes, CYP1A1, GSTM1, micronucleus, cigarette smoking