The effects of a number of 4-nitroquinoline 1-oxide and 4-nitropyridine I-oxide derivatives, with varying carcino genic potencies, on the scission of proteins linking DNA were studied in cultured mouse fibroblasts, strain L . P3. With twenty-two 4-nitroquinoline I-oxide derivatives and twelve 4-nitropyridine 1-oxide derivatives tested, an excel lent correlation was found between the scission ef...

The effect of the carcinogen, 4-nitroquinoline 1-oxide, on cultured mouse fibroblasts, strain L-P3, a substrain of L-929, was studied. Cells were cultured in a proteinand lipid-free synthetic medium, DM-120. Strand breakage and repair of DNA caused by 4-nitroquinoline 1-oxide was examined. 4-Nitroquinoline 1-oxide caused singleand double-strand breaks of DNA as shown by alkaline and neutral suc...

rearrangement of the nucleolonema and pars amorpha of the nucleolus. In addition to being carcinogenic, 4-nitroquinoline-N-oxide and several of its derivatives have been shown to be potent mutagenic agents (18). Thus, 4-nitroquinoline-N-oxide has been reported to exert mutagenic effects in bacterial systems and in viruses (4). Yeast cells (18) after exposure to 4-nitro quinoline-N-oxide gave ri...

The effect of 4-nitroquinoline 1-oxide on the cell-mediated immune response was tested in C57BL/6 female mice. The carcinogen was administered s.c. either 30 days before or just prior to grafting the female recipients with C57BL/6 male skin. Skin graft survival times were noticeably prolonged in mice that received the carcinogen 30 days before grafting. Administration of 4-nitroquinoline 1-oxid...

correlations between carcinogenicity and several molecular orbital characteristics were found. All correlations between molecular orbital properties and carcinogenicity were modified by one or more of the following structural factors: (a) the absence of a 4-nitro group, (b) the absence of a 1-oxide group, or (c) the presence of bulky substituents in position 2 or 3 of the quinoline ring. Any of...

The effect of 4-nitroquinoline 1-oxide on the cell-mediated immune response was tested in C57BL/6 female mice. The carcinogen was administered s.c. either 30 days before or just prior to grafting the female recipients with C57BL/6 male skin. Skin graft survival times were noticeably prolonged in mice that received the carcinogen 30 days before grafting. Administration of 4-nitroquinoline 1-oxid...

of breakage increased, recovery was incomplete, and the fraction which was still unrepaired after recovery incubation increased. Concomitant with repair of DNA the growth capacity of the cells was regained. However, as the unrepaired fraction increased with increase in the concentration of 4NQO, the viability of the cells decreased. Cell killing induced by 4NQO was suggested to be due to disord...