PMID: 2565937May 1, 1989

DNA damage and repair in rodent and human cells after exposure to JANUS fission spectrum neutrons: a minor fraction of single-strand breaks as revealed by alkaline elution is refractory to repair

International Journal of Radiation Biology
M J PeakC K Hill


We have examined the induction and repair of breaks induced in the DNA of Chinese hamster V79 and human P3 epithelial teratocarcinoma cells by JANUS fission-spectrum neutrons (mean energy 0.85 MeV) and 60Co gamma radiation in the biological dose range, using alkaline filter elution methods. Fission-spectrum neutrons induce fewer immediate single-strand breaks (ssb) per gray of absorbed dose than do gamma rays, as measured by alkaline elution methods. Previous survival measurements have indicated incomplete recovery after neutron exposures. The present data demonstrate that whereas most ssb caused by exposure to fission-spectrum neutrons can be rapidly repaired by both cell lines, a small but statistically significant fraction of the ssb induced by exposure to 6 Gy of neutrons is refractory to repair. In contrast, all measurable ssb induced by 3 Gy gamma rays are rapidly repaired.


Mar 1, 1976·Proceedings of the National Academy of Sciences of the United States of America·D L DugleJ D Chapman
Dec 1, 1974·Proceedings of the National Academy of Sciences of the United States of America·R B PainterH J Burk

Related Concepts

Cobalt Radioisotopes
DNA, Double-Stranded
Genotoxic Stress
Base Excision Repair
DNA, Neoplasm
DNA, Single-Stranded
X-Rays, Nuclear

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