The shape of the dose-response curve and the saturation of the Elkind repair.

Mammalian cells in culture exhibit a well-known radiation response curve typical of a number of cell lines. Various models were used for a suitable interpretation of experimental data with the purpose of fitting a smooth curve between the given points. Regardless of the choice of a specific model, the final consequence of the exponential behaviour at high doses is the saturation effect of the double dose (Elkind) repair. Namely, if the cells are exposed to two equal doses of radiation separated with a time interval, the survival rate increases with the length of the time interval and achieves the maximum value at 3 h time interval if, for instance, V-79 cells are used as experimental material.