Refine
Has Fulltext
- yes (80)
Is part of the Bibliography
- yes (80)
Year of publication
Document Type
- Journal article (68)
- Book article / Book chapter (6)
- Conference Proceeding (4)
- Review (2)
Keywords
- Toxikologie (68)
- DNA (6)
- DNA binding (5)
- Genotoxicity (5)
- Carcinogen (4)
- Carcinogenesis (3)
- Carcinogens (3)
- Ernährung (3)
- Medizin (3)
- Aflatoxin (2)
- Ames test (2)
- Benzene (2)
- DNA Binding (2)
- Dose response (2)
- Dose-response relationship (2)
- Estrogen (2)
- Hormone (2)
- binding (2)
- carcinogen (2)
- (Rat liver) (1)
- (Salmonella) (1)
- 1 (1)
- 2-Acetylaminofluorene (1)
- 2-Dichloroethane (1)
- 2-acetylaminofluorene (1)
- 4'-hydroxylation (1)
- 4-(p-nitrobenzyl)pyridine (1)
- 8-Hydroxy-deoxyguanosine (1)
- Aflatoxin B1 (1)
- Alkylation (1)
- Amino acid composition (1)
- Amino acids (1)
- Aminosäuren (1)
- Anabolieagent (1)
- Aniline derivatives (1)
- Anthraquinone glycosides (1)
- Aryl hydrocarbon rnonooxygenase (1)
- Benzo(a)pyrene-DNA binding (1)
- Cancer prevention (1)
- Carcinogen risk Individual susceptibili (1)
- Carcinogenic potency (1)
- Carcinogenicity (1)
- Carcinogenität (1)
- Chemical carcinogenesis (1)
- Choline deficiency (1)
- Chromosome aberration (1)
- Covalent DNA binding (1)
- Covalent binding (1)
- Covalent binding index (1)
- Covalent binding index - Diethylstilbestrol (1)
- Cytochrome b5 (1)
- DNA binching (1)
- DNA damage (1)
- DNA methylation (1)
- DNA-Binding (1)
- DNS-Bindung (1)
- Electrophiles (1)
- Emodin (1)
- Endogenous genotoxicity (1)
- Enzyme induction (1)
- Epoxide hydrolase (1)
- Estrone (1)
- Gastric carcinogenesis (1)
- Genetic instability (1)
- Glutathione Stransferase (1)
- Immunization (1)
- Inhalation (1)
- Krebs (1)
- Krebs <Medizin> (1)
- MammaJian mutagenicity test (1)
- Mechanism of action (1)
- Metabolic activation (1)
- Metabolism saturation (1)
- Micronucleus test (1)
- Mutagenicity assay (1)
- Mutagens (1)
- Mutation assay (1)
- N-methyl-N-nitrosourea (1)
- Nitrosation (1)
- Nitrosierung (1)
- Oxygen radical (1)
- Pointmutation (1)
- Protein binding (1)
- Protein coding (1)
- Quantitative risk assessment (1)
- Radicals (1)
- Rat (1)
- Rat Iiver microsomes (1)
- Rat liver peroxisome (1)
- Reactive intermediates (1)
- Riot control agents (1)
- Risikoanalyse (1)
- Risk estimation (1)
- Salmonella typhimurium (1)
- Salmonella/microsome assay (1)
- Sensitivity (1)
- Short-term Carcinogenicity Test (1)
- Short-term tests (1)
- Spontaneous tumours (1)
- Structureactivity relationship (1)
- Styrol (1)
- Thymidine glycol (1)
- Toluene (1)
- Transgenic mouse (1)
- Transgenie mice (1)
- Trenbolone (1)
- Tritiated Water (1)
- Zellteilung (1)
- adduct (1)
- aflatoxin (1)
- aflatoxin B1 (1)
- alkylation (1)
- allelic variant (1)
- amine (1)
- amino acid (1)
- covalent (1)
- covalent binding (1)
- cytochrome P450 2C9 (1)
- diet (1)
- dose (1)
- endogenous (1)
- ethanol (1)
- extrapolation (1)
- genotoxic (1)
- heterogeneous population (1)
- impact pharmacogenetics (1)
- in vivo (1)
- individual (1)
- liver microsomes (1)
- mutagen (1)
- natural (1)
- nitrosation (1)
- nitroso compound (1)
- o-Chlorobenzylidene malononitrile (1)
- risk (1)
- stomach (1)
- susceptibility (1)
- tolbutamide substrate (1)
- tumour (1)
- urea (1)
- warfarin polymorphisms (1)
Institute
- Institut für Pharmakologie und Toxikologie (80) (remove)
Tbe alkylating potency of unstable N-nitrosamino acids and N-nitrosopeptides was investigated in vitro using 4-(para-nitrobenzyl)pyridine (NBP) as nucleophile. Of the amino acids, Met and those with an aromatic side chain were the most potent. The relative overall alkylating potency was 23:10:5:4:2:1: for Trp, Met, His, 1)rr, Phe and Gly, respectively. The homo-dipeptides were much more potent than the amino acids, with relative potencies of 400:110:100:8:3:1, for Trp-Trp, l)T-'I)T, Met-Met, Asp-Asp, Phe-Phe and Gly, respectively. In the one-phase reaction system (in which NBP is already present durlog the nitrosation reaction at acidic pH), all amino acids tested showed a second-order reaction for nitrite. In the two-phase system (in which NBP is added only after bringing the nitrosation reaction mixture to neutrality), all amino acids tested except one again showed a second-order reaction for nitrite (Phe, His, Asp and the dipeptide artiticial sweetener aspartame); only Met under these conditions bad a reaction order of one for nitrite. This could mean that nitrosation of the side chain of Metproduces a second N-nitroso product which is relatively stable in acid but reacts with NBP under neutral conditions. In the human stomach, this side-chain nitrosation might become more important than the reactions at the primary amino group, firstly because of the greater stability of the product(s) in acid and secondly because of the tirst-order reaction rate for nitrite. A decrease in nitrite concentration from the millimolar concentrations ofthe in-vitro assay to the micromolar concentrations in the stomach reduces the reaction rate by a factor of 1000 for the side-chain nitrosation, whereas a million-fold reduction will be observed for nitrosation of the amino group.