Kinetics of excision repair synthesis induced by N-acetoxy-2-acetylaminofluorene and ultraviolet irradiation in human diploid fibroblasts

Journal Article · Mon Aug 01 00:00:00 EDT 1977 · J. Natl. Cancer Inst.; (United States)

OSTI ID:7316484

Poirier, M C ^[1]; DeCicco, B T

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1. National Cancer Inst., Bethesda, MD

The rate of DNA repair synthesis was studied with the use of (/sup 3/H)thymidine to pulse confluent, hydroxyurea-treated human diploid fibroblasts (WI-38) at intervals up to 76 hours after treatment with either 45 erg uv irradiation/mm/sup 2/ or 10 ..mu..m N-acetoxy-2-acetylaminofluorene (NA-AAF). These doses induced equal repair incorporation during the first 4 hours after exposure. During this initial period, the uv-treated cells showed an almost linear increase in repair synthesis, whereas the chemically treated cells showed a lag from 0 to 30 minutes, followed by a linear incorporation from 30 minutes to 4 hours. After uv exposure, the rate of DNA repair synthesis was highest from 0 to 4 hours and decreased considerably by 8 to 12 hours, so that by 24 to 28 hours, the rate was only 20 percent of that from 0 to 4 hours; by 72 to 76 hours, incorporation was close to levels of the nonirradiated controls. The rate of repair synthesis after continuous NA-AAF administration decreased much more slowly, and by 72 to 76 hours was still about 50 percent of that from 0 to 4 hours. Removal of NA.AAF from the cultures at 4 hours reduced the 72- to 76-hour incorporation to 30 percent of the 0- to 4-hour value. These characteristic profiles of DNA repair synthesis were observed through a range of doses of both uv and NA-AAF, from conditions where cell survival was good to conditions approaching lethality.

• OSTI ID: 7316484
• Journal Information: J. Natl. Cancer Inst.; (United States), Vol. 59:2
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
DNA
BIOLOGICAL REPAIR
BIOSYNTHESIS
FIBROBLASTS
BIOLOGICAL RADIATION EFFECTS
HYDROCARBONS
BIOLOGICAL EFFECTS
HYDROXYUREA
DOSE-RESPONSE RELATIONSHIPS
FLUORENE
TIME DEPENDENCE
ULTRAVIOLET RADIATION
AMIDES
ANIMAL CELLS
AROMATICS
BIOLOGICAL RECOVERY
CONDENSED AROMATICS
CONNECTIVE TISSUE CELLS
ELECTROMAGNETIC RADIATION
HYDROXY COMPOUNDS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
RADIATION EFFECTS
RADIATIONS
RECOVERY
REPAIR
SOMATIC CELLS
SYNTHESIS
560121* - Radiation Effects on Cells- External Source- (-1987)