Repair Kinetics of DNA-DSB Induced by X-rays or Carbon Ions under Oxic and Hypoxic Conditions

• DOI: 10.1269/jrr.46.325
• Publication Date: 2005-10-06T05:55:58Z
• Authors: Ryoichi HIRAYAMA; Yoshiya FURUSAWA; Takeshi FUKAWA; Koichi ANDO
• Keywords: Oxygen enhancement ratio; Linear energy transfer; Carbon fibers

We studied the relation between initial DNA double-strand breaks (DNA-DSB) and rejoining kinetics of strand breaks, as well OER (oxygen enhancement ratio) after low- high-LET (linear energy transfer) radiations. CHO cells were exposed to 200 kVp X-rays or 80 keV/μm carbon ions under oxic hypoxic conditions. DNA-DSB in analyzed by a static-field gel electrophoresis (SFGE). The could be described sum fast slow components. released X-ray irradiation was higher for irradiated an condition than that condition. 5.7. This value decreased rapidly 3.4 with component 15 minutes. On other hand, ion 2.2, this not changed incubation. values cell killing 2.8 1.8 irradiations, respectively. These matched complete rejoining. conclude is important factor mechanism oxygen effect.