Heterogeneity of N-Acetyltransferase Genotype among Japanese in the Tohoku District

N-acetylation is a major route of biotransformation for xenobiotics containing aromatic amine or hydrazine groups which are converted to aromatic amides and hydrazides, respectively. The reaction is mediated by N-acetyltransferases 1). Genetic polymorphisms of N-acetyltransferase 2 (NAT2) have been established to be responsible for slow and fast acetylator phenotypes. A large number of compounds including benzidine, 2-aminoflourene, β-naphtylamine, aniline, hydrazine and caffeine are acetylated and their rates of metabolism depend on the genotypes in individuals 1). In addition, epidemiological evidence indicates that phenotypic polymorphism of NAT2 is associated with host susceptibility to carcinogenesis induced by aromatic amines 2). The primary aim of the present study is to investigate genotypes among Japanese from different areas. Information on genotypic distribution may stimulate the development of metabolic epidemiology for workers exposed to various aromatic amines. It is very useful not only for evaluation of biological monitoring exposure indices, but also for the assessment of regional differences in susceptibility. We also attempted, in this report, to evaluate whether daily consumption of caffeine-containing beverages can predict acetylation phenotypes.