[Radiobiological constant in irradiation stimulation of cells for the subsequent adaptive response]

It was shown that the maximum adaptive response to damaging irradiation dose would be achieved after preirradiation when for latter the product of the dose by the dose rate (i. e. D*D/t) is equal to constant value. The radiobiological constant is the reciprocal of this product, i. e. k = t/D2 = tau/delta 2, where delta is an average dose received by the cell for single pass of ionizing particle through the cell sensitive volume with a given density. The triggering signal for the adaptive response program initiated by preirradiation is a certain reaction, which is completed for a time interval tau between two consistent acts of absorption. The radiobiological constant is determined by this time interval tau and by a dose delta. In human lymphocytes in the case of signal initiated by X-rays the value of tau is within the range of 1--5 s.