Mutagenicity and carcinogenicity of mono- and diacetyl hydrazine

Two hydrazine derivatives, monoacetyl hydrazine (MAH) and diacetyl hydrazine (DAH), have been tested for mutagenic response in the Salmonella/mammalian microsome assay and micronucleus test. MAH but not DAH, increased the revertant mutants in TA100 and TA1535 and also increased the frequency of micronuclei in polychromatic erythrocytes. Gavage administration of MAH but not of DAH, resulted in increased incidence of lung tumors. These observations record for the first time the mutagenicity/carcinogenicity of MAH which is one of the metabolites of isoniazid in animals and humans.