DNA repair and chromosome aberrations: the effect of cytosine arabinoside on the frequency of chromosome aberrations induced by radiation and chemicals

Journal Article · Tue Jan 01 04:00:00 EST 1980 · Teratog., Carcinog., Mutagen.; (United States)

OSTI ID:5658182

Preston, R J

The frequency of x-ray-induced chromosome aberrations in G/sub 0/ human lymphocytes was greatly increased when cells were incubated with cytosine arabinoside (ara-C) after irradiation. The frequency of dicentrics increased with increasing ara-C incubation times (one, two, and three hours). Lymphocytes from Down syndrome individuals were more sensitive to aberration induction by x-rays in G/sub 0/, and the increase in dicentric frequency with ara-C incubation was much more rapid than with normal cells. When G/sub 2/ normal lymphocytes were x-irradiated and incubated for two or three hours with ara-C until fixation, there was a large increase in depletion frequency compared to cells x-irradiated and incubated in the absence of ara-C. However, no exchanges were observed in the presence of ara-C, compared to 0.29 per cell as when x-rays alone were given. These results form the basis for a discussion of the mechanism of aberration induction by x-rays. Experiments with two chemicals, 4-nitroquinoline-N-oxide and methyl methanesulfonate, show that chromosome-type aberrations can be induced in G/sub 1/ treated lymphocytes incubated with ara-C. However, these chemicals in the absence of ara-C incubation, induced no aberrations in G/sub 1/ at the concentrations used. The mechanism of aberration induction is discussed, particularly in terms of whether or not chemicals can be defined as S-phase dependent.

• Research Organization: Oak Ridge National Lab., TN
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5658182
• Journal Information: Teratog., Carcinog., Mutagen.; (United States), Journal Name: Teratog., Carcinog., Mutagen.; (United States) Vol. 1; ISSN TCMUD
• Country of Publication: United States
• Language: English

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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AMINES
ANIMAL CELLS
ANIMALS
ANTINEOPLASTIC DRUGS
AZINES
BIOLOGICAL EFFECTS
BIOLOGICAL MATERIALS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
BLOOD
BLOOD CELLS
BODY FLUIDS
CELL CULTURES
CELL CYCLE
CHROMOSOMAL ABERRATIONS
CONNECTIVE TISSUE CELLS
CYTOSINE
DNA
DOSES
DRUGS
ELECTROMAGNETIC RADIATION
HETEROCYCLIC COMPOUNDS
IN VITRO
INHIBITION
IONIZING RADIATIONS
IRRADIATION
LEUKOCYTES
LYMPHOCYTES
MAMMALS
MAN
MATERIALS
MUTATIONS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PRIMATES
PYRIMIDINES
RADIATION DOSES
RADIATION EFFECTS
RADIATIONS
RADIOINDUCTION
RADIOSENSITIVITY EFFECTS
RECOVERY
REPAIR
SOMATIC CELLS
VERTEBRATES
X RADIATION