DNA strand breaks and repair in lymphocytes after chronic low dose oxidant stress in vivo

Conference · Mon Feb 26 04:00:00 EST 1990 · FASEB Journal (Federation of American Societies for Experimental Biology); (United States)

OSTI ID:5979898

James, J; Enger, S; Makinodan, T ^[1]

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1. VAMC WLA, Los Angeles, CA (United States)

In contrast to the well-documented negative effects of high dose oxidant exposure, accumulating evidence supports a positive, perhaps essential physiologic role for very low level oxidant stress. For example, low level oxidant exposure, within or below the physiologic range, has been reported to stimulate membrane signal transduction, proliferation, antioxidant defense, and DNA repair. In the present study, the authors pursue the possibility that whole body exposure to low dose radiation (LDR) induces an up-regulation in the accumulation and repair of DNA strand breaks in lymphocytes. C57BI/6 mice were exposed for 4 weeks to 0.04 Gy/day of {gamma} radiation as a model of low level oxidant stress. End points measured in spleen cells after chronic in vivo LDR included; (1) constitutive expression of DNA strand breaks; (2) sensitivity to oxidant-induced DNA damage; (3) repair of DNA strand breaks after mitogen stimulation; (4) ADP-ribosyl transferase (ADPRT) activity. The results indicated that the constitutive level of DNA strand breaks was significantly decreased after chronic LDR, and associated with a decrease in ADPRT activity. However, DNA repair capacity was not enhanced relative to sham-irradiated mice. These results suggest that cumulative DNA damage and associated repair activity are both adaptively reduced after chronic LDR and may reflect an up-regulation in mechanisms of antioxidant defense.

• OSTI ID: 5979898
• Report Number(s): CONF-9104107--
• Conference Information: Journal Name: FASEB Journal (Federation of American Societies for Experimental Biology); (United States) Journal Volume: 4:3
• Country of Publication: United States
• Language: English

Related Subjects

560152 -- Radiation Effects on Animals-- Animals
560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL MATERIALS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
BLOOD
BLOOD CELLS
BODY FLUIDS
CHRONIC EXPOSURE
CONNECTIVE TISSUE CELLS
DNA REPAIR
ELECTROMAGNETIC RADIATION
ELEMENTS
ENZYMES
GAMMA RADIATION
IN VIVO
IONIZING RADIATIONS
IRRADIATION
LEUKOCYTES
LOW DOSE IRRADIATION
LYMPHOCYTES
MAMMALS
MATERIALS
MICE
NONMETALS
ORGANIC COMPOUNDS
OXYGEN
PROTEINS
RADIATION EFFECTS
RADIATIONS
RECOVERY
REPAIR
RODENTS
SENSITIVITY
SOMATIC CELLS
SPLEEN CELLS
STRAND BREAKS
TRANSFERASES
VERTEBRATES