Alan H. Gerulath, Ti Li Loo
Sep 1, 1972
Citations
1
Influential Citations
53
Citations
Quality indicators
Journal
Biochemical pharmacology
Abstract
Abstract 5-(3,3-Dimethyl-1-triazeno)imidazole-4-carboxamide (DIC) is more lethal to Chinese hamster ovary cells and human malignant melanoma cells in culture in the presence than in the absence of light. Incubation of either cell line with DIC labeled at the side chain methyl groups with 14 C resulted in the association of radioactivity with DNA only if light was absent. However, with ring-labeled DIC-2- 14 C, radioactivity was found in both DNA and RNA fractions regardless of the presence or absence of light during incubation. These results are essentially consistent with the current consensus regarding the mode of decomposition of DIC: on exposure to light, DIC undergoes decomposition to dimethylamine and 5-diazoimidazole-4-carboxamide which interacts with nucleic acids in an obscure manner. When light is excluded, however, an alternative pathway of decomposition is followed, with the ultimate formation of 5-aminoimidazole-4-carboxamide and a methyl carbonium ion, which then interacts with cell DNA.