title: G2 cells: progression delay and survival.
abstract: The progression of Chinese hamster ovary (CHO) G2 cells into mitosis and their survival was measured after X-ray doses up to 4.0 Gy. S-phase cells were prevented from reaching mitosis by labeling with 125IUdR for 10 min prior to irradiation of the exponentially growing monolayer of cells. Mitotic cells, located past the radiation-induced division delay transition point, did not suffer a delay and were selected separately prior to the recovery of the G2 cells. The results show that (1) up to 400 min after radiation only 55% of the G2 cells recovered after about 2.5 Gy; (2) the progression delay of the G2 cells that recovered was 52.5 min/Gy; and (3) the survival curve D0 for these cells, 2.45 Gy, indicated a radioresistant population.
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000528:radiation effects; D006224:Cricetinae; D003412:Cricetulus; D004307:Dose-Response Relationship, Radiation; D005260:Female; D007399:Interphase / Q000528:radiation effects*; D008938:Mitosis / Q000528:radiation effects; D010053:Ovary; D013997:Time Factors