Low dose effects on cultured mammalian cells…

Low dose effects on cultured mammalian cells… 1 first-author 1 1 1 1 1 1 1 1 Institute of Modern Physics, the Chinese Academy of Sciences, Lanzhou 730000 Institute of Modern Physics, the Chinese Academy of Sciences, Lanzhou 730000 The low dose effects induced by carbon ions on Chinese hamster V79 cells and murine melanoma B16 cells were investigated in this paper. Both cell lines were divided into four groups for irradiation: (1) control, (2) 0.02 Gy or 0.05 Gy( D 1), (3) 1 Gy( D 2), (4) D 1+ D 2. The survivors and micronuclei were studied as biological endpoints. The results of group (1) and group (2) showed that there were no obvious differences on micronucleus frequency but there were significant increases when irradiation dose was 0.02Gy on colony formation efficiency. Although low dose ion irradiation could not contribute to DNA damages, it could enhance the colony formation efficiency. In the study of group (3) and (4), when the ion dose was 0.02 Gy, there were evident increases on surviving fraction and decreases on micronuclcus frequency, but there were no statistical changes on these endpoints when the ion dose was 0.05Gy. This meant that high LET radiation could induce the adaptive response of cultured cells, furthermore, in the range of inducing ion dose low dose irradiation was more profitable than high dose one. Low dose effect Carbon ions Mammalian cell Adaptive response Surviving fraction Micronucleus frequency LET (linear energy transfer) References Luckey T D . Hormesis with ionizing radiation , CRC Press , 1980 , 1 ~ 122 Hormesis with ionizing radiation Olivieri G , Bodycote J , Wolff S . Science , 1984 , 223 ( 5 ): 594 ~ 597 Science Wolff S , Jostes R M , Cross F T et al . Mutat Res , 1991 , 250 ( 3 ): 299 ~ 306 Mutat Res Brooks A L. Mcdonald K E. Kimsey B B et al . Low dose irradiation and biological defense mechanisms , Elsevier Science Publishers , 1992 , 391 ~ 322 Low dose irradiation and biological defense mechanisms Zhang H , Zheng R L , Wei Z Q et al . Int J Radiat Biol , 1998 , 73 ( 2 ): 163 ~ 167 Int J Radiat Biol Lui S Z . Hormesis with low level of ionizing radiation (in Chinese) , Beijing : Science Press . 1996 , 181 Hormesis with low level of ionizing radiation (in Chinese) Q691, R730 Supported by "Hope for the West" Fund of the Chinese Academy of Science (No. XB 980604) 2000-03-13 2000-11-01 2021-02-05 2000 Nuclear Science and Techniques 4 11