harmine and aniline

Mutagenic/carcinogenic 9-(4'-aminophenyl)-9H-pyrido[3,4-b]indole [aminophenylnorharman (APNH)] is formed from norharman and aniline in the presence of cytochrome P450 3A4/1A2. Because both precursors are widely distributed in the environment, human exposure is unavoidable. To clarify APNH formation in the human body, amounts of the compound in 24-h human urine collected from smokers and nonsmokers, eating a normal diet, were analyzed by liquid chromatography/electrospray ionization tandem mass spectrometry. In addition, norharman and aniline were also analyzed by high-performance liquid chromatography and gas chromatography, respectively. APNH could be detected in all urine samples at levels 49 to 449 pg for smokers and 21 to 594 pg for nonsmokers per 24-h urine, respectively. The amounts of norharman and aniline were 46 to 185 ng and 0.70 to 8.10 microg for smokers and 52 to 447 ng and 0.49 to 5.72 microg for nonsmokers, respectively, per 24-h urine (none of the levels differing significantly between smokers and nonsmokers). To exclude exogenous exposure to norharman and aniline, we analyzed the levels of APNH, norharman, and aniline in urine samples collected from inpatients receiving parenteral alimentation. Similar to the healthy volunteers, all urine samples contained 12 to 338 pg of APNH, 6 to 75 ng of norharman, and 0.33 to 1.86 microg of aniline per 24-h urine. These results suggest that APNH should be considered as a novel endogenous mutagen/carcinogen; thus, it is very important to determine the biological significance of this carcinogen for human cancer development.

Topics: Adult; Aniline Compounds; Carbolines; Carcinogens; Chromatography, High Pressure Liquid; Cytochrome P-450 Enzyme System; Female; Harmine; Humans; Indoles; Japan; Male; Middle Aged; Mutagens; Pyridines; Smoking

A novel mutagenic compound, 9-(4'-aminophenyl)-9H- pyrido[3,4-b]indole (aminophenylnorharman, APNH), is shown to be formed by the in vitro enzymatic reaction of 9H-pyrido[3,4-b]indole (norharman) and aniline. APNH generates DNA adducts (dG-C8-APNH), and is potently genotoxic to bacteria and mammalian cells. APNH has also been demonstrated to be formed in vivo from norharman and aniline, and suggested to be a new type of endogenous mutagenic compound. To determine its carcinogenic activity, long-term administration of APNH was investigated in 93 male and 90 female F344 rats. Rats were fed diets containing 0, 20 or 40 p.p.m. from 7 weeks of age. All animals were killed after 85 weeks treatment and necropsy was performed. Hepatocellular carcinomas (HCCs) were induced at incidences of 10 and 79% in male rats fed 20 and 40 p.p.m. APNH, and 34% in female rats fed 40 p.p.m. of APNH, respectively. In addition, colon adenocarcinomas were found at incidences of 3 and 9% in male rats, and 4 and 13% in female rats fed 20 and 40 p.p.m. of APNH, respectively. Other tumors, including thyroid carcinomas and mononuclear cell leukemia, were also seen in rats fed APNH. Polymerase chain reaction-single strand conformation polymorphism analysis revealed beta-catenin gene mutations in 24% of HCCs and K-ras, beta-catenin and Apc gene mutations were found in 22, 44 and 33% of colon cancers induced by APNH, respectively. Most mutations occurred at G:C base pairs. beta-Catenin protein accumulations in the nucleus and cytoplasm were also revealed in both liver and colon tumors. Thus, APNH induced liver and colon cancers with K-ras, beta-catenin and Apc gene mutations in F344 rats.

Topics: Adenocarcinoma; Aniline Compounds; Animals; beta Catenin; Carbolines; Carcinoma, Hepatocellular; Colon; Colonic Neoplasms; Cytoskeletal Proteins; Female; Genes, APC; Genes, ras; Harmine; Indoles; Leukemia; Liver; Liver Neoplasms; Male; Mutagens; Mutation; Polymerase Chain Reaction; Polymorphism, Single-Stranded Conformational; Pyridines; Rats; Rats, Inbred F344; Thyroid Neoplasms; Trans-Activators

Mutagenic 9-(4'-aminophenyl)-9H-pyrido[3,4-b]indole (aminophenylnorharman, APNH), formed from norharman and aniline in the presence of S9 mix, is thought to be accountable for the co-mutagenic action of norharman. Our previous studies suggest that cytochrome P-450s (CYPs) are involved in the generation of APNH. In order to identify the responsible CYP species in the present study, norharman (8 mg) and aniline (4 mg) were incubated with individual recombinant human CYPs (2 nmol) at 37 degrees C for 20 min. Formation of APNH was observed with CYP1A1, CYP1A2, CYP1B1, CYP2B6, CYP2D6, CYP2E1 and CYP3A4, but not with CYP2A6, CYP2C9 and CYP2C19. The amounts of APNH from norharman and aniline were 33 ng for CYP1A1, 15 ng for CYP3A4, 7 ng for CYP2D6, 6 ng for CYP1A2 and 5 ng for CYP2B6. APNH formation in the presence of CYP1B1 and CYP2E1 was very low at around one fiftieth of that with CYP3A4. When CYP selective chemical inhibitors, such as furafylline for CYP1A2 and ketoconazole for CYP3A4, were added to the reaction mixture of norharman, aniline and human microsomes, formation of APNH was decreased to 14 and 16% of the control level, respectively. Moreover, human lung microsomes also showed the activity of APNH formation from norharman and aniline, albeit at only one hundredth of that with liver microsomes. In general, content in human liver microsomes is rather high for CYP3A4 and CYP1A2 but relatively low for CYP2D6 and CYP2B6, at about 30, 10, 1.5% and less than 1% of the total CYP, respectively. Although CYP1A1 showed the highest APNH formation activity, its expression in human liver is reported to be below the level of detection. Based on these observations, it is suggested that the practical major contributors to the formation of APNH from norharman and aniline are CYP3A4 and CYP1A2, the responsible reactions mainly occurring in the liver.

Topics: Aniline Compounds; Carbolines; Chromatography, High Pressure Liquid; Cytochrome P-450 Enzyme System; Harmine; Indoles; Mutagens; Pyridines; Spectrophotometry, Ultraviolet

Aminophenylnorharman (APNH) is formed from non-mutagenic norharman and aniline, and is mutagenic to Salmonella typhimurium TA98 with S9 mix. Norharman and aniline are present in cigarette smoke and cooked foods and both compounds are detected in human urine samples, suggesting that APNH could be a mutagenic and carcinogenic human risk factor. The purpose of the present study was to determine the in vivo mutagenicity of APNH. Male gpt delta transgenic mice were fed a diet containing 10 or 20 p.p.m. APNH for 12 weeks. The gpt mutant frequency (MF) in the liver increased 10-fold in 20 p.p.m. APNH-treated mice, which was almost equivalent to the MF observed in the liver of the same transgenic mice treated with 300 p.p.m. 2-amino-3,8-dimethylimidazo[4,5-f] quinoxaline for 12 weeks. In the colon mucosa, the gpt MF increased approximately 5-fold in 20 p.p.m. APNH-treated mice. Our results suggest that APNH is a strong hepatic mutagen in mice. The APNH-induced gpt mutations in the liver were dominated by G:C to T:A transversions, followed by G:C to A:T transitions. They also included single G:C deletions in G:C run sequences and 2 bp deletions: GCGC to GC and CGCG to CG. The Spi- deletion MF in the liver was 13-fold higher in 20 p.p.m. APNH-treated mice, relative to the control, and were dominated by single base pair deletions, in particular, in G:C run sequences. Large deletions were rare. The mutational characteristics induced by APNH are compared with those induced by other heterocyclic amines, and the human risk of APNH is discussed.

Topics: Aniline Compounds; Animals; Carbolines; Carcinogens; Colon; Colonic Neoplasms; CpG Islands; DNA Mutational Analysis; Dose-Response Relationship, Drug; Gene Deletion; Harmine; Humans; Indoles; Liver; Liver Neoplasms; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Models, Chemical; Mucous Membrane; Mutagens; Mutation; Pyridines; Time Factors

Norharman is not mutagenic to Salmonella strains, but becomes so to S. typhimurium TA98 and YG1024 with S9 mix in the presence of the non-mutagenic aromatic amine, aniline. The mutagenicity from norharman and aniline in the presence of S9 mix is reported to be due to formation of a mutagenic compound, 9-(4'-aminophenyl)-9H-pyrido[3,4-b]indole (aminophenylnorharman, APNH). In the present study, we examined which enzymes might be involved in in vitro formation of APNH from norharman and aniline. When norharman (5mg) and aniline (2.5mg) were incubated with S9 mix, the S9 fraction of which was prepared from the livers of rats treated with phenobarbital (PB) and beta-naphthoflavone (beta-NF), at 37 degrees C for 20 min, 496 ng of APNH was produced. Formation of APNH was also detected with the microsomal fraction, but not with the cytosol fraction. The addition of a p450 inhibitor, SKF-525A, to the reaction mixture at a dose of 5mM resulted in a decrease of APNH formation, to around 40% of the control level. These results suggest involvement of p450 enzyme(s) in the formation of APNH from norharman and aniline. Moreover, a microsomal fraction from human liver was demonstrated to have the capacity to produce APNH from norharman and aniline, similar to the case with the microsomal fraction from rat liver. When norharman (90 mg/kg) and aniline (90 mg/kg) were administered to rats by gavage, APNH could be detected in the urine, at a rate of 19.6 ng+/-16.9 ng per 24h. The level was increased by treatment of the urine samples with hydrochloric acid, suggesting some APNH was excreted into urine as conjugated forms. Thus, it is likely that APNH may be produced from norharman and aniline in the human body.

Topics: Aniline Compounds; Animals; Carbolines; Carcinogens; Chromatography, Gas; Chromatography, High Pressure Liquid; Cytochrome P-450 Enzyme Inhibitors; Cytochrome P-450 Enzyme System; Enzyme Inhibitors; Harmine; In Vitro Techniques; Indoles; Male; Microsomes, Liver; Proadifen; Pyridines; Rats; Rats, Inbred F344

A mutagenic heterocyclic amine (HCA), 9-(4'-aminophenyl)-9H-pyrido[3,4-b]indole (aminophenylnorharman, APNH), is produced in the presence of S9 mix by the reaction of norharman and aniline, both of which are nonmutagenic and abundantly present in our environment. It has been previously reported that APNH-DNA adducts were detected in DNA of Salmonella typhimurium strain incubated with APNH and S9 mix. In the present study, we examined the structures of APNH-DNA adducts using the (32)P-postlabeling method and various spectrometry techniques. When the reaction mixture of N-acetoxy-APNH and 2'-deoxyguanosine 3'-monophosphate (3'-dGp) was analyzed, three adduct spots (two major and one minor) were observed by (32)P-postlabeling under modified-standard conditions. No adduct formation was observed for reaction mixtures of N-acetoxy-APNH with 3'-dAp, 3'-dTp, or 3'-dCp. The two major adduct spots (spots 1 and 2) detected by TLC were extracted and subjected to HPLC along with the standards 3',5'-pdGp-C8-APNH and 5'-pdG-C8-APNH, which were independently chemically synthesized. On the basis of the results of co-chromatography, spots 1 and 2 were identified to be 5'-monophosphate and 3',5'-diphosphate forms of dG-C8-APNH. When the extract of spot 2 (3',5'-pdGp-C8-APNH) was further digested with nuclease P1 and phosphodiesterase I, a spot corresponding to spot 1 (5'-pdG-C8-APNH) was newly observed on TLC. From these observations, both of the two major spots were concluded to be dG-C8-APNH. A similar DNA adduct pattern to that apparent in vitro was observed in various organs of F344 rats fed 40 ppm of APNH for 4 weeks. The levels of APNH-DNA adducts were highest in the liver and colon, with RAL values of 1.31 +/- 0.26 and 1.32 +/- 0.11 adducts/10(7)nucleotides, respectively. Thus, APNH was demonstrated to form DNA adducts primarily at the C-8 position of guanine residues in vitro and in vivo, like other mutagenic and carcinogenic HCAs.

Topics: Aniline Compounds; Animals; Carbolines; Colon; DNA Adducts; Drug Interactions; Harmine; Indoles; Liver; Male; Mutagens; Pyridines; Rats; Rats, Inbred F344; Tissue Distribution

Aminophenylnorharman (APNH) is a newly identified mutagenic heterocyclic amine formed by coupling of norharman with aniline in the presence of S9 mix. Furthermore, mutagenic amino-3'-methylphenylnorharman (AMPNH) and aminophenylharman (APH) have been identified from a reaction mixture of norharman and o-toluidine and that of harman and aniline, respectively, with S9 mix. Among these three heterocyclic amines, APNH shows most potent mutagenic activity towards Salmonella typhimurium TA98 and YG1024 with S9 mix. In the present study, the induction of sister chromatid exchanges (SCEs) by APNH was examined in Chinese hamster lung (CHL) cells in vitro, comparing it to those of AMPNH and APH. On incubation with rat S9 for 6h, followed by a recovery culture period of 18h, a dose-dependent effect was found at concentrations between 0.00125 and 0.01 microg/ml for APNH and between 0.3125 and 5 microg/ml for AMPNH and APH. The approximate chemical concentrations leading to a three-fold of control SCE levels calculated from slopes of the linear regressions of induced SCEs were 0.005 for APNH, 0.51 for AMPNH and 1.7 microg/ml for APH. Because of the very strong SCE-causing ability of APNH, we further explored its genotoxicity by examining the induction of chromosome aberrations in CHL cells. A dose-dependent effect was found for chromosome aberrations at concentrations between 0.00125 and 0.04 microg/ml of APNH. The aberrations observed were primarily chromatid exchanges (cte) and breaks (ctb). In conclusion, the potency of SCE induction and clastogenic activity induced by APNH is stronger than Actinomycin D, Mitomycin C (MMC) or 1,8-dinitropyrene which are considered to be the potent clastogens in the literature. Further studies are needed for elucidating mechanisms of the genotoxic actions of these compounds and for evaluating their potential hazards to human health.

Topics: Aniline Compounds; Animals; Carbolines; Carcinogens; Cell Line; Chromosome Aberrations; Cricetinae; Cricetulus; DNA Adducts; Harmine; Indoles; Lung; Mitomycins; Mutagens; Pyridines; Salmonella typhimurium; Sister Chromatid Exchange

9-(4'-Aminophenyl)-9H-pyrido [3,4-b] indole (aminophenylnorharman, APNH) is a novel mutagenic heterocyclic amine, produced by the reaction of norharman with aniline in the presence of S9 mix. In the present study, the maternal and developmental toxicity of APNH were investigated in ICR mice administered oral doses of 0, 0.625, 1.25, 2.5 or 5 mg/kg/day on gestational days (GD) 6 through 15 or 0, 5, 10, or 20 mg/kg on GD 12. Maternal and foetal parameters were evaluated on day 18 of gestation. Foetuses of dams treated on GD 6-15 were examined for external and skeletal malformations and variations, and foetuses of dams treated on GD 12 were inspected for cleft palate. Maternal death occurred when APNH was administered at 5 mg/kg/day on GD 6-15. No significant decrease in body weight gain during the administration period was observed at doses of 2.5 mg/kg/day or less when applied on GD 6-15. Adverse changes in general condition of dams were observed in the groups treated at doses of 2.5 mg/kg/day and above on GD 6-15, whereas no adverse effects on dams were noted even when APNH was applied at a fairly high dose on GD 12. Intracytoplasmic vacuolation in hepatocytes, necrosis of proximal tubular epithelial cells and desquamation of necrotic epithelial cells in the tubular lumen were observed in dams treated with APNH at 2.5 or 5 mg/kg/day on GD 6-15. Increased preimplantation loss was observed at 5 mg/kg/day and post-implantation loss was observed at 2.5 mg/kg/day and above when applied on GD 6-15, or at 20 mg/kg when applied on GD 12. Foetal body weight was decreased by APNH in a dose-dependent manner. The frequency of external malformations (cleft palate) was significantly increased in the group treated with APNH at 2.5 mg/kg/ day on GD 6-15 compared to the controls. However, there were no foetuses with cleft palate even when APNH was given at 20 mg/kg on GD 12. No significant increases in skeletally malformed foetuses were found in any APNH-treated group. The frequency of lumbar ribs was increased dose dependently. This study demonstrated the developmental toxicity of a mutagenic compound, APNH, in mice at maternally toxic doses, and that cleft palate observed in term foetuses resulted from the adverse effect of APNH on the maternal environment during organogenesis. More detailed studies are warranted to assess the possible risks to pregnant women from exposure to APNH.

Topics: Aniline Compounds; Animals; Carbolines; Cleft Palate; Female; Fetus; Harmine; Humans; Indoles; Liver; Male; Maternal Exposure; Mice; Mice, Inbred ICR; Mutagens; Pregnancy; Pyridines

Norharman (9H-pyrido[3,4-b]indole), which is a heterocyclic amine included in cigarette smoke or cooked foodstuffs, is not mutagenic itself. However, norharman reacts with non-mutagenic aniline to form mutagenic aminophenylnorharman (APNH), of which DNA adducts formation and hepatocarcinogenic potential are pointed out. We investigated whether N-OH-APNH, an N-hydroxy metabolite of APNH, can cause oxidative DNA damage or not, using 32P-labeled DNA fragments. N-OH-APNH caused Cu(II)-mediated DNA damage. When an endogenous reductant, beta-nicotinamide adenine dinucleotide (NADH) was added, the DNA damage was greatly enhanced. Catalase and a Cu(I)-specific chelator inhibited DNA damage, suggesting the involvement of H(2)O(2) and Cu(I). Typical -*OH scavenger did not inhibit DNA damage. These results suggest that the main reactive species are probably copper-hydroperoxo complexes with DNA. We also measured 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) formation by N-OH-APNH in the presence of Cu(II), using an electrochemical detector coupled to a high-pressure liquid chromatograph. Addition of NADH greatly enhanced 8-oxodG formation. UV-VIS spectra and mass spectra suggested that N-OH-APNH was autoxidized to nitrosophenylnorharman (NO-PNH). We speculated that NO-PNH was reduced by NADH. Cu(II) facilitated the redox cycle. In the presence of NADH and Cu(II), very low concentrations of N-OH-APNH could induce DNA damage via redox reactions. We conclude that oxidative DNA damage, in addition to DNA adduct formation, may play an important role in the expression of genotoxicity of APNH.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aniline Compounds; Carbolines; Copper; Deoxyguanosine; DNA; DNA Damage; Harmine; Indoles; Models, Chemical; Mutagens; NAD; Oxidation-Reduction; Pyridines

9-(4'-Aminophenyl)-9H-pyrido[3,4-b]indole [aminophenylnorharman (APNH)] is a novel mutagenic heterocyclic amine, produced by the reaction of norharman with aniline in the presence of S9 mix. In the present study, the acute toxicity of this compound was investigated in male F344 rats. Ten-week-old animals were treated with a single intragastric injection of APNH at doses of 45 or 90 mg/kg body wt and euthanized 1, 3, or 6 days afterward. When APNH was administered at a dose of 90 mg/kg, vacuolation of Sertoli cells in the testis was seen at 1 day after treatment. The testicular damage had markedly progressed by day 6, with multinucleated giant cells and loss of round spermatids in the seminiferous tubules observed in groups 1 and 2 of the four histological categories of spermatogenesis. Numbers of spermatogonia were also decreased by APNH treatment. No toxic changes were observed in Leydig cells under these conditions and serum follicle-stimulating hormone and luteinizing hormone concentrations were also unchanged from control values. Such severe testicular damage was not observed at any time point at the 45 mg/kg dose level of APNH. Moreover, neither norharman nor aniline alone exerted acute testicular toxicity at doses equivalent to 90 mg/kg of APNH. In addition to the testicular lesions, erosive changes of urinary bladder, thymic atrophy, and panmyelophthisis were evident in rats given APNH at 90 mg/kg.

Topics: Administration, Oral; Aniline Compounds; Animals; Body Weight; Carbolines; Carcinogens; Follicle Stimulating Hormone; Harmine; Indoles; Luteinizing Hormone; Male; Mutagens; Organ Size; Pyridines; Rats; Rats, Inbred F344; Seminiferous Tubules; Testis

Norharman (9H-pyrido[3,4-b]indole), widely distributed in our environment, including cigarette smoke and cooked foodstuffs, is not mutagenic to Salmonella strains, but becomes mutagenic to S.typhimurium TA98 and YG1024 with S9 mix in the presence of non-mutagenic aromatic amines such as aniline and o-toluidine. To elucidate the mechanisms of co-mutagenicity, we tried to isolate the mutagen(s) produced by a reaction between norharman and aniline with S9 mix. By HPLC purification, two mutagenic compounds (I and II), one (I) showing mutagenicity with and the other (II) without S9 mix, were isolated. The structure of compound I was deduced to be a coupled compound of norharman and aniline, 9-(4'-aminophenyl)-9H-pyrido[3,4-b]indole (aminophenylnorharman), by a variety of spectrometry techniques and this was confirmed by its chemical synthesis. The mutagenic activity of this novel heterocyclic amine was tested using the pre-incubation method and was found to induce 187,000 revertants in TA98 and 1,783,000 revertants in YG1024 per microg with S9 mix. Compound II was shown to be hydroxyaminophenylnorharman. Formation of the same DNA adducts was observed in YG1024 when aminophenylnorharman or a mixture of norharman plus aniline was incubated with S9 mix. The hydroxyamino derivative also yielded the same DNA adducts in YG1024. Thus, the appearance of mutagenicity by norharman with aniline in the presence of S9 mix suggests that the coupled mutagenic compound, aminophenylnorharman, is formed from norharman and aniline, then converted to the hydroxyamino derivative and forms DNA adducts to induce mutations in TA98 and YG1024.

Topics: Aniline Compounds; Animals; Carbolines; DNA Adducts; Harmine; Microsomes, Liver; Mutagens; Rats

Various kinds of mutagenic and carcinogenic heterocyclic amines (HCAs) are produced by heating protein-rich foods, such as meat and fish. To evaluate the risk of these HCAs in terms of human cancer development, exposure levels must be measured. We therefore analyzed their amounts in various kinds of cooked foods and in urine samples of healthy volunteers living in Tokyo. Based on the obtained quantitative data, daily exposure levels to 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) were calculated to be 0.3-3.9 and 0.005-0.3 microgram per person, respectively. Moreover, human DNA samples were analyzed with the 32P-postlabeling method, and colon, rectum and kidney tissues were found to contain an adduct spot corresponding to the standard 5'-pdG-C8-MeIQx by TLC and HPLC, at levels of 14, 18 and 1.8 per 10(10) nucleotides, respectively. The beta-carboline compound, norharman, is produced by heating L-tryptophan, and is known to be present in cooked foods and in cigarette smoke at higher levels than mutagenic and carcinogenic HCAs. While norharman is not itself mutagenic to Salmonella, it does become mutagenic to S. typhimurium TA98 with S9 mix in the presence of non-mutagenic aromatic amines like aniline and o-toluidine. When we examined whether DNA adducts are formed in the DNA of S. typhimurium TA98 by treatment with norharman and aromatic amines using 32P-postlabeling analysis, DNA adduct formation by norharman with aromatic amines was found to be related to the appearance of mutagenicity by norharman with aromatic amines.

Topics: Aniline Compounds; Carbolines; Colon; Diet; DNA Adducts; Environmental Exposure; Female; Harmine; Humans; Imidazoles; Male; Meat; Mutagenicity Tests; Quinoxalines; Salmonella typhimurium; Toluidines

Norharman, widely distributed in our environment, is alone not mutagenic to Salmonella typhimurium TA98 and TA100 either with or without S9 mix, but becomes mutagenic to S.typhimurium TA98 with S9 mix when non-mutagenic aromatic amines like aniline or o- or m-toluidine are added. Thus norharman has been called a 'co-mutagen'. In the present study we examined whether or not DNA adducts are formed in DNA of S.typhimurium TA98 by treatment with norharman and aromatic amines using 32P-post-labeling analysis under modified adduct intensification conditions. When a sample of norharman (8 mg) and aniline (4 mg) was incubated with 4 ml of overnight culture of S.typhimurium TA98 in the presence of 20 ml S9 mix for 6 h at 37 degrees C, three adduct spots were detected at a total relative adduct labeling (RAL) of 10.8 +/- 2.27/10(8) nucleotides. Under the same conditions, a mixture of norharman (8 mg) and o-toluidine (4 mg) yielded three adduct spots at a RAL of 3.74 +/- 1.71/10(8) nucleotides. With a combination of norharman and m-toluidine, a single adduct spot was seen at a RAL of 0.04 +/- 0.01/10(8) nucleotides. In contrast, norharman with p-toluidine did not produce adduct spots. Furthermore, neither norharman nor the aromatic amines themselves gave any evidence of adducts. Thus DNA adduct formation by norharman with aromatic amines correlates with the co-mutagenic action of norharman in S.typhimurium TA98.

Topics: Amines; Aniline Compounds; Animals; Biotransformation; Carbolines; DNA Adducts; Harmine; Male; Microsomes, Liver; Mutagenicity Tests; Mutagens; Rats; Rats, Sprague-Dawley; Salmonella typhimurium; Toluidines

In human lymphocytes, aniline was unable to induce an increase of SCEs in vitro with or without metabolic activation by S9 mix. p-Aminophenol, one of the C-hydroxylation metabolites of aniline in the body, however, increased the SCE frequencies of lymphocytes at a concentration of 10-4 M. The addition of norharman to aniline plus S9 mix increased the SCE frequencies. The increase, however, was due to the SCE-inducing activity of norharman. These data show that the addition of norharman, which enhances the sensitivity of the Salmonella/microsome test, does not produce an enhancement of the sensitivity of the SCE test.

Topics: Alkaloids; Aminophenols; Aniline Compounds; Animals; Biotransformation; Carbolines; Crossing Over, Genetic; Harmine; Humans; Lymphocytes; Male; Microsomes, Liver; Rats; Sister Chromatid Exchange

Topics: Alkaloids; Aniline Compounds; Aniline Hydroxylase; Animals; Carbolines; Harmine; Male; Microsomes, Liver; p-Dimethylaminoazobenzene; Rats

The carcinogenic effects of aniline and norharman given alone or in combination were examined in rats. Neoplastic changes including hyperplastic changes of the urinary bladder were not found in all groups. Papillomas of forestomach were observed in 5 rats out of 110 rats. However, this was not significantly different among the groups. Pyelonephritis or chronic nephritis were also seen in all groups. Hematological and blood biochemical analysis did not show any notable difference in the animals treated with aniline and/or norharman.

Topics: Alkaloids; Aniline Compounds; Animals; Carbolines; Carcinogens; Harmine; Kidney Diseases; Male; Papilloma; Pituitary Neoplasms; Rats; Stomach Neoplasms; Urinary Bladder Neoplasms