Effect of oxygen on DNA strand breaks in irradiated thymocytes

Journal Article · Sat Dec 01 04:00:00 EST 1973 · Int. J. Radiat. Biol., v. 24, no. 6, pp. 621-625

DOI:https://doi.org/10.1080/09553007314551551· OSTI ID:4345560

Lennartz, M; Coquerelle, T; Hagen, U

Single and double-strand breaks were determined in DNA of rat thymocytes irradiated with 10-MeV electrons over a range of 0 to 6 Mrads in the presence of O/sub 2/ or N/sub 2/, under rapid conditions where the repair of breaks should have been negligible. The numbers of double and single strand breaks in irradiated cells increased linearly with dose. The ratio between single and double strand breaks was 19.5 plus or minus 1.3 in DNA from cells irradiated under O/sub 2/ and N/sub 2/. DNA from irradiated cells contained fewer singlestrand breaks after heating than after alkaline denaturation. The frequency of single strand breaks in unirradiated DNA was identical after both methods of denaturation. The ratio of the slopes of the dose-effect curves yielded 27.8% plus or minus 3.8% alkali labile breaks under O/sub 2/ and 49.8 plus or minus 4.7% under N/sub 2/. An o.e.r. of ~3.7 was deduced from these results for the initial yield of single- and doublestrand breaks in irradiated mammalian cells. (UK)

• Research Organization: Kernforschungszentrum, Karlsruhe, Ger.
• NSA Number: NSA-29-018565
• OSTI ID: 4345560
• Journal Information: Int. J. Radiat. Biol., v. 24, no. 6, pp. 621-625, Journal Name: Int. J. Radiat. Biol., v. 24, no. 6, pp. 621-625; ISSN IJRBA
• Country of Publication: United Kingdom
• Language: English

Related Subjects

*DNA-- STRAND BREAKS
*OXYGEN-- RADIOSENSITIVITY EFFECTS
*STRAND BREAKS-- RADIOINDUCTION
*THYMOCYTES-- BIOLOGICAL RADIATION EFFECTS
DOSE- RESPONSE RELATIONSHIPS
ELECTRON BEAMS
ELECTRONS
MEV RANGE 10-100
N48200* --Life Sciences--Radiation Effects on Cells
NITROGEN
OXYGEN ENHANCEMENT RATIO
RATS
RESPONSE MODIFYING FACTORS