Growth kinetics of Bp8 mouse ascites sarcoma after single doses of whole body irradiation. II. Analysis of the progression of cells through the cell cycle.
Bp8 ascites sarcoma cells growing in vivo were whole body irradiated with doses of 1.75 to 8 Gy. The inflow and outflow rates of cells in the various compartments of the cell cycle were estimated on the basis of sequential analysis of the total number of cells and from the proportion of cells in G1, S-phase, G2 and M. The flow through the compartments was calculated from these data and from the sizes of the cell pools. The durations of the mitotic delay, the G1-depletion and the early G2 blockage were linearly related to the dose. After release of the mitotic division delay the accumulation rate of cells in M and G1 decreased linearly with the dose; for G2, plateau values for the accumulation rate were found after 2.5 Gy. The outflow rates from G2 and M after release of the G2 blockage showed a shoulder type of dose-response with a D0 of 2.5 Gy and a n value of 1.5. In addition to an increase in the duration of G2, generally responsible for the increase in the total cell cycle time at about 24 hours after irradiation and an increase in the duration of the S-phase up to 12 hours after irradiation, an early increase in the duration of G1 and M was observed.
D000818:Animals; D002452:Cell Count; D002453:Cell Cycle / Q000528:radiation effects*; D002455:Cell Division / Q000528:radiation effects; D002460:Cell Line; D005434:Flow Cytometry; D007399:Interphase / Q000528:radiation effects; D008297:Male; D051379:Mice; D008940:Mitotic Index / Q000528:radiation effects; D009368:Neoplasm Transplantation; D012513:Sarcoma, Experimental / Q000473:pathology*; D013997:Time Factors; D014916:Whole-Body Irradiation