[The appearance of a fracture of radioresistant cells in a fibroblast population irradiated at high doses].

Two sublines of Djungarian DEF 4/21 hamster cells survived after gamma irradiation with the doses of 10 and 20 Gy were obtained. The survived cell posterity (SCP) of both cell lines are considerably more clonogenic. They show a higher proliferative activity and a shorter period of generation than the control cells. The sublines are several times more radioresistant as compared to the original cells. After exposure to high doses of radiation, the cell culture of the SCP exhibits a 17 to 20% high-resistant fraction. Supposedly, the cells of this fraction are responsible for repopulation after exposure to lethal doses of gamma irradiation.