[Population kinetics of microcolonies causing "shouldered" survival curves at low LET].
The well-known fact that the dose dependence of cell survival, when measured by the macrocolony-forming test, can be fitted with the multitarget expression is re-investigated by considering the delayed loss of cellular reproductivity in a microcolony. As the reproductive capacity of each single cell of the microcolony must be lost in order to prevent the development of a macrocolony, the reproductive death of a microcolony is in mathematical analogy to the multitarget model and provides the biological explanation for its formal applicability. Published data from colony-size distributions and the model of "latent genetical damage" are utilized to understand the exponential dose dependence of single cell survival in a microcolony. Exponential survival curves obtained at high LET are explained by an undelayed loss of reproductivity in the irradiated cell. The restitution of the "shoulder" in delayed-plating and split-dose experiments is interpreted by repair effects.
D000818:Animals; D002470:Cell Survival / Q000528:radiation effects*; D004735:Energy Transfer; D007700:Kinetics; D008433:Mathematics; D013223:Statistics as Topic
Die Populationskinetik von Mikrokolonien als Ursache für die "Schulter" von Uberlebenskurven bei niedrigem LET.