Radiation-induced DNA strand breaks in EL4 cells and mouse spleen lymphocytes

방사선에 의한 EL4 마우스 백혈병세포 및 정상 마우스 비장 임파구 DNA strand breaks의 측정

  • Kim, Sung-ho (Laboratory of Radiation Medicine, Korea Cancer Center Hospital) ;
  • Kim, Tae-hwan (Laboratory of Radiation Medicine, Korea Cancer Center Hospital) ;
  • Chung, In-yong (Laboratory of Radiation Medicine, Korea Cancer Center Hospital) ;
  • Yoo, Seong-yul (Laboratory of Radiation Medicine, Korea Cancer Center Hospital) ;
  • Cho, Chul-koo (Laboratory of Radiation Medicine, Korea Cancer Center Hospital) ;
  • Chin, Soo-yil (Laboratory of Radiation Medicine, Korea Cancer Center Hospital)
  • 김성호 (원자력병원 방사선의학연구실) ;
  • 김태환 (원자력병원 방사선의학연구실) ;
  • 정인용 (원자력병원 방사선의학연구실) ;
  • 류성렬 (원자력병원 방사선의학연구실) ;
  • 조철구 (원자력병원 방사선의학연구실) ;
  • 진수일 (원자력병원 방사선의학연구실)
  • Received : 1991.03.25
  • Published : 1991.07.31

Abstract

The filter elution technique was used to assay $^{60}Co$ $\gamma$ ray-induced DNA strand breaks(SB) in EL4 mouse leukemia cell and mouse spleen lymphocyte. The lymphocytes were stimulated with lipopolysaccharide (LPS, $20{\mu}g/ml$) to label $[^3H]$ thymidine. EL4 cells and lymphocytes in suspension were exposed at $0^{\circ}C$ to 0Gy, 1Gy, 5Gy, 10Gy or l5Gy for DNA single strand breaks(SSB) assay and 0Gy, 25Gy, 50Gy, 75Gy or 100Gy for DNA double strand breaks(DSB) assay of $^{60}Co$ radiation and elution procedure was performed at pH12.1 and 9.6. The number of DNA strand breaks increased with increasing doses of r rays. The strand scission factor(SSF) was estimated in each experiment (eluted volume 21ml). The slope of SSB EL4 cells was $0.01301{\pm}0.00096Gy^{-1}$ (n=5), the slope of SSB for lymphocytes was $0.01097{\pm}0.00091Gy^{-1}$ (n=5) and the slope of DSB for lymphocytes was $0.001707{\pm}0.0000573Gy^{-1}$ (n=5). Thus EL4 cells were more sensitive to induction of DNA SSB by ionizing radiation than lymphocytes (p<0.005). The ratio of slope of dose-response relationship (SSF versus dose) of lymphocytes DNA SSB as compared with the slope of DNA DSB was 6.4.