ABSTRACT
Mutagenicity of seven aromatic amines, two heterocyclic amines, two azo compounds and one polycyclic aromatic hydrocarbon was examined with a fluctuation test modified by Gatehouse. The test was performed by using Salmonella typhimurium TA98 in the presence of liver and bladder S9 from PCB pretreated rats. Seven out of 12 compounds showed mutagenic activities with liver S9 and seven with bladder S9. Benzidine, 3-methylcholanthrene and 2-acetylaminofluorene showed a negative response with bladder S9 but a positive response with liver S9. The mutagenicity of the seven compounds observed with bladder S9 had a lower sensitivity than with liver S9. 3-Amino-1,4-dimethyl-5H-pyrido[4,3-b]indole and 3-amino-1-methyl-5H-pyrido[4,3-b]indole showed mutagenic activity at lower concentrations than the other compounds which showed mutagenic activity either with bladder S9 or liver S9. Mutagenicity of 3-methylcholanthrene was observed at high concentration only in the presence of liver S9. The findings from the present study suggested that aromatic amines, heterocyclic amines and polycyclic aromatic hydrocarbons were more likely to be activated to strong mutagens with liver S9 than with bladder S9.
Subject(s)
Liver/metabolism , Mutation , Urinary Bladder/metabolism , Amines/pharmacokinetics , Amines/toxicity , Animals , Azo Compounds/pharmacokinetics , Azo Compounds/toxicity , Biotransformation , Male , Mutagenicity Tests/methods , Polycyclic Compounds/pharmacokinetics , Polycyclic Compounds/toxicity , Rats , Rats, Inbred Strains , Salmonella typhimurium/geneticsABSTRACT
The genotoxicity of 9 chemicals used as epoxy resin hardeners was examined in the DNA repair test with rat hepatocytes. DNA repair synthesis was elicited by 7 chemicals, i.e., 4-aminodiphenyl ether, 4,4-diaminodiphenyl ether, 3,4,4'-triaminodiphenyl ether, 3,3'-dichloro-4,4'-diaminodiphenyl ether, 1,3-phenylenedi-4-aminophenyl ether, 4,4'-diaminodiphenyl methane and 4,4'-methylene-bis(2-chloroaniline). The positive results obtained with 4 epoxy resin hardeners of unknown carcinogenicity, i.e., 4-amino-diphenyl ether, 3,4,4'-triaminodiphenyl ether, 3,3'-dichloro-4,4'-diaminodiphenyl ether and 1,3-phenylene-di-4-aminophenyl ether suggest that they may be carcinogens. The genotoxicity of 1,4-phenylene-di-4-aminophenyl ether, of unknown carcinogenicity, and 4,4'-diaminodiphenyl sulfone, for which there is no sound proof of carcinogenicity, was not confirmed in the DNA repair test. The result with 4,4'-diaminodiphenyl sulfone was in agreement with its lack of mutagenicity in Salmonella typhimurium.
Subject(s)
DNA Repair/drug effects , Epoxy Resins , Phenyl Ethers/toxicity , Animals , Cells, Cultured , DNA/biosynthesis , In Vitro Techniques , Liver , Male , Mutagenicity Tests , RatsABSTRACT
Mutagenicity of nine epoxy resin hardeners was examined by a fluctuation test modified by Gatehouse. The test was performed by using Salmonella typhimurium TA98 with a metabolic activation system. In our laboratory, the results of the fluctuation test were compared with the results obtained by the previously mentioned Ames preincubation method. Six out of nine epoxy resin hardeners showed mutagenic activity in both the fluctuation test and Ames preincubation method, but one out of the nine was negative in both test systems. Two out of the nine were positive by either of the two testing systems. The fluctuation test is disadvantageous in that it is marginally slower and requires slightly more labor than the Ames test and furthermore it is difficult to increase the amount of microsome because of background interference. These disadvantages, however, are somewhat offset by the advantages that small organs such as urinary bladder can be used instead of liver cells and that a small amount of microsome can be employed for metabolic activation. This test is also suitable for testing aqueous samples containing low levels of mutagen.
