[Changes in cellular proliferative activity after exposure to irradiation at low doses].

Cell proliferation, colony size, and the level of DNA damage in HeLa cells subjected to acute gamma-radiation (60Co, 75 cGy/min) in a dose of 10-40 cGy and in the descendant generations were studied. Radiation was found to reduce proliferative activity in cell generations distant from irradiation, to cause a reduction in the number of cells in colonies, and to induce DNA damages which could be revealed by the treatment of cells with a mixture of the reparative and replicative DNA synthesis inhibitors arabinosylcytosine (araC) and hydroxyurea (HU). The effect value and duration increased with the increase in radiation dose.