Comparative study of DNA radiolysis by fast neutrons and γ-rays
| Autor: | Melanie Spotheim-Maurizot, Michel Charlier, C. Savoye, R. Sabattier |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
inorganic chemicals
DNA Repair DNA damage Cysteamine Astrophysics::High Energy Astrophysical Phenomena Radiation-Protective Agents Radiation Models Biological Fast Neutrons chemistry.chemical_compound Relative biological effectiveness Humans Radiology Nuclear Medicine and imaging Chemistry Radiochemistry Gamma ray DNA Neutron temperature Oxygen Oncology Gamma Rays Radiolysis Oxygen enhancement ratio Copper Relative Biological Effectiveness DNA Damage Plasmids |
| Zdroj: | Bulletin du Cancer/Radiothérapie. 83:27s-31s |
| ISSN: | 0924-4212 |
| Popis: | The effect of fast neutrons on cells is different from that of gamma-rays: the relative (to gamma) biological effect (RBE) is higher than one and the oxygen enhancement ratio (OER) is lower than that of gamma-rays. We searched for differences between the effects of the two radiations on DNA, the critical target of radiations. Using a model plasmid DNA we observed that for the same absorbed dose, fast neutrons induce twice fewer single strand breaks (SSB) and 1.5 more double strand breaks (DSB) than gamma-rays. A transition metal ion, the Cu++, is a better sensitizer of DNA breakage with fast neutrons than with gamma-rays. In anoxia, cysteamine, a positively charged thiol, is a better radioprotector against neutrons than against gamma-rays. In presence of cysteamine, the OER is lower for neutrons than for gamma-rays. These results are discussed in terms of different physical properties of the two types of radiation. |
| Databáze: | OpenAIRE |
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