EVIDENCE ON N-ACETYLTRANSFERASE ALLELE-ASSOCIATED METABOLISM OF HYDRAZINE IN JAPANESE WORKERS

Hydrazine (N2H4), which has been categorized as a weak carcinogen, is a chemical with the one of the largest Production rates in Japan. We h ave investigated the effects of acetylation phenotypes on the metaboli sm of hydrazine, Genotypes of N-acetyl transferases, NAT2, were deter mined using polymerase chain reaction for 297 male workers. Biological and exposure monitoring were also conducted, The rapid and intermedia te acetylators accounted for 45% each, and the slow acetylators accoun ted for 10%, Biological half-lives were significantly different among the three acetylation phenotypes (analysis of variance, P < 0.05): 3.9 4 +/- 1.70 hours for slow acetylators, 2.25 +/- 0.37 hours for interme diate acetylators, and 1.86 +/- 0.67 hours for rapid acetylators. Amon g Japanese, rapid and intermediate acetylators are the major phenotype s, which is in sharp contrast with those among Caucasians, We conclude that biological monitoring should take genetic factors, which may var y dramatically among different populations, into account.