0000000000420076
AUTHOR
H. Schwind
Species differences in activating and inactivating enzymes related to the control of mutagenic metabolites
Microsomal monooxygenases catalyze the biosynthesis of epoxides from olefinic and aromatic compounds whilst microsomal epoxide hydratase and cytoplasmic glutathione S-transferases are responsible for their further biotransformation. Although catalytically very efficient the cytoplasmic glutathione S-transferases play, due to their subcellular localization, a minor role in the inactivation of epoxides derived from large lipophilic compounds and were, therefore, not included in this study. It was shown with such a lipophilic compound, benzo(a)pyrene, as a model substance and with liver enzyme mediated bacterial mutagenesis as biological endpoint that species and strain differences in epoxide …
Mutagenicity of Closely Related Carcinogenic and Noncarcinogenic Compounds Using Various Metabolizing Systems and Target Cells
A total of 49 heteropolycyclic compounds belonging to structurally homogenous series was investigated for bacterial mutagenicity in the Ames test. The same batches of compounds were tested for carcinogenicity by injection into subcutaneous tissue of mice? 22 test compounds were carcinogenic, some strongly, others weakly. With the exception of one weak carcinogen, all these compounds were mutagenic. However, 15 of 27 noncarcinogens (56%) were also mutagenic. Moreover, noncarcinogenic, weakly carcinogenic, and strongly carcinogenic mutagens showed very similar mutagenic potencies.