Kinetics of Ionizing
Irradiation-induced DNA Strand Breaks
Shao Chun-Lin1*, Saito Masahiro2, Yu
Zeng-Liang1
( 1Institute of Plasma Physics, Chinese Academy of Sciences, P O
Box 1126, Hefei 230031, China； 2Research Reactor Institute, Kyoto
University, Osaka 590-0494,
Japan )
Abstract By
measuring the dose effect of ionizing irradiation-induced single- and double-
strand breaks (SSB and DSB) of pBR322, the responses of the yields of SSB and
DSB to DNA concentrations were obtained. It was found that, in the presence of
mannitol, the reciprocals of G(SSB) and G(αDSB) had a linear
relationship to the reciprocal of DNA concentration so that the competition
reaction of DNA and mannitol to ・OH radicals could be described by a
second-order kinetics. Moreover, the rate coefficients and the efficiencies of
the ・OH radical inducing SSB and αDSB were deduced.
Key words irradiation； DNA strand breaks； kinetics
*Corresponding author： Tel, 86-551-5591602； Fax, 86-551-5591310； e-mail, [email protected]