Article

Human promyelocytic leukemia (HL – 60) cells were irradiated with 0.5- 110 Gy gamma irradiation and studied for 48 h post irradiation to determine the mode of death. HL – 60 cells are much more sensitive to radiation-induced loss of clonogenicity (D0 = 2.2 Gy) than to induction of apoptosis at 6 h ( D0 for nonapoptotic cells = 32.6 Gy ). Maximum apoptosis occurred 48 h after irradiation with doses 3.5-10 Gy, and cells that died by necrosis were found in 8-42%.