Ascorbate enhances u. v. -mutagenesis in E. coli but inhibits it in Chinese hamster cells

Journal Article · Thu May 01 00:00:00 EDT 1986 · Carcinogenesis; (United States)

DOI:https://doi.org/10.1093/carcin/7.5.727· OSTI ID:5687674

Rossman, T G; Klein, C B; Naslund, M

Ascorbic acid (vitamin C) causes an increase in the mutation frequency of u.v.-irradiated Escherichia coli WP2. The enhancement occurs at all u.v. fluences, and is dependent upon the ascorbate concentration in the medium. A maximum effect (approximately 8- to 13-fold) is seen at 100-150 micrograms/ml, although some enhancement can be seen even at 10 micrograms/ml. The comutagenic effect of ascorbate with u.v. in E. coli is dependent upon peptone, a constituent of nutrient broth. The enhancement of u.v.-mutagenesis by ascorbate is absent in strains WP2s (uvrA) and WP6 (polA), suggesting that ascorbate affects the repair of pyrimidine dimers. The opposite results are observed for u.v.-mutagenesis in Chinese hamster V79 cells. The presence of ascorbate (50 micrograms/ml) during u.v. irradiation does not enhance the u.v. effect, but rather decreases it approximately 30%. These results are discussed with regard to differences in the mechanism of u.v.-mutagenesis and DNA repair in bacterial and mammalian cells.

• Research Organization: New York Univ. Medical Center, NY
• OSTI ID: 5687674
• Journal Information: Carcinogenesis; (United States), Vol. 5
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ASCORBIC ACID
GENETIC RADIATION EFFECTS
RADIOSENSITIVITY EFFECTS
CHO CELLS
ESCHERICHIA COLI
PYRIMIDINE DIMERS
DNA REPAIR
CULTURE MEDIA
DOSE-RESPONSE RELATIONSHIPS
MUTAGENESIS
MUTATION FREQUENCY
ULTRAVIOLET RADIATION
ANIMAL CELLS
BACTERIA
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
ELECTROMAGNETIC RADIATION
GENETIC EFFECTS
MICROORGANISMS
RADIATION EFFECTS
RADIATIONS
RECOVERY
REPAIR
VITAMINS
560121* - Radiation Effects on Cells- External Source- (-1987)
560131 - Radiation Effects on Microorganisms- Basic Studies- (-1987)