Cellular recovery in two sub-lines of the L5178Y murine leukaemic lymphoblast cell line differing in their sensitivity to ionizing radiation.
Cellular recovery was assessed in two sublines of L5178Y murine lymphoma cells of differing radiosensitivity (LY-S and LY-A4) using low dose-rate irradiation and split-dose experiments. No increase in cell survival was observed in the LY-S cell line until the dose-rate was reduced to 2 cGy/min, whereas in the LY-A4 cell line 20 cGy/min was low enough to detect changes in survival. The extent of this change, as assessed by dose reduction factors at 2 logs of cell kill, was greater in the LY-A4 cell line. Fitting these data with the incomplete repair model of Thames led to anomalous values for the half-time of repair. In split-dose experiments the maximum observed recovery ratio increased as a function of dose in a manner that is consistent with the linear-quadratic equation. As was found previously with radiosensitive human tumour cells, the LY-S cell line showed more split-dose recovery at any given dose than the LY-A4 cell line.
Radiotherapy Research Unit, Institute of Cancer Research, Sutton, Surrey, UK.
T J
TJ
McMillan
J J
JJ
Eady
J H
JH
Peacock
G G
GG
Steel
D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D007940:Leukemia L5178 / Q000503:physiopathology*; D011836:Radiation Tolerance / Q000502:physiology*