Kinetics of repair of DNA double strand breaks after low and high LET irradiation
DNA double strand breaks (DSB) are the critical lesions for the inactivation of yeast cells. In DSB-repair deficient cells one DSB is lethal. The molecular interpretations of potentially lethal damage (PLD) and its repair (PLDR) are as follows: PLD corresponds to a certain number of DSB, the lethal expression of which may be modified by alterations in postirradiation conditions. Reasons for shouldered survival curves may be saturable repair or misrepair of accumulated DSB leading to cell death. Increase of the t(1/2) values of DSB-repair kinetics does not mean necessarily that the repair process is saturable. As far as the kinetics of DSB-repair is exponential, although the t(1/2) value increases with dose, the repair process is unsaturated. For yeast cells it is found that the survival curves are exponential when repair of DSB is allowed only under non-growth conditions. As soon as the cells are allowed to repair DSB under growth conditions (after liquid holding or without), shouldered survival curves are observed.
Bibliographic Reference: Paper presented: Colloquium of the Department of Radiation and Radiology Therapy, Winston-Salem, NC (US), June 21, 1988
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Record Number: 198910859 / Last updated on: 1994-12-01
Original language: en
Available languages: en