Shape of dose-survival curves for mammalian cells and repair of potentially lethal damage analyzed by hypertonic treatment
During the usual procedure of testing cell survival by colony-forming ability, repair of potentially lethal damage (PLD) takes place. By incubating the cells in hypertonic suspension a certain part of this repair can be inhibited, leading to an exponential dose-survival curve as expected from the Poisson distribution of lethal events in the cells. If such a hypertonic treatment is performed after increasing intervals following irradiation with x rays, curves with increasing shoulder length are obtained. Quantitative analysis of the kinetics of this repair shows that PLD is repaired for about 1 h after irradiation by a saturated repair system which eliminates about one lesion per 15 min per cell independent of the applied absorbed dose. PLD not eliminated by this last system is repaired by an unsaturated system with a time constant of several hours. Repair of PLD after x irradiation proceeds quantitatively in this way in plateau-phase cells suspended in a conditioned medium, which seems optimal for such repair. If these cells are suspended after irradiation in normal nutrient medium a certain fraction of the PLD is transformed into irreparable damage. The final survival after repair in nutrient medium is then identical with that obtained by the usual measurement of colony-forming ability on nutrient agar. This indicates that the shoulder in dose-survival curves for plateau phase cells ispartly due to repair of PLD and partly due to manifestation of this damage during repair time.
- Research Organization:
- Gesellschaft fuer Strahlen, Frankfurt am Main, Germany
- OSTI ID:
- 6042410
- Journal Information:
- Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 87:3; ISSN RAREA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Study of the repair of potentially lethal and sublethal radiation damage in Chinese hamster cells exposed to extremely hypo- or hypertonic NaCl solutions. [X rays]
Evidence that repair and expression of potentially lethal damage cause the variations in cell survival after x irradiation observed through the cell cycle in Ehrlich ascites tumor cells
Related Subjects
560121* -- Radiation Effects on Cells-- External Source-- (-1987)
62 RADIOLOGY AND NUCLEAR MEDICINE
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
COLONY FORMATION
DISPERSIONS
DOSE-RESPONSE RELATIONSHIPS
ELECTROMAGNETIC RADIATION
HYPERTONIC SOLUTIONS
IONIZING RADIATIONS
MAMMALS
MIXTURES
RADIATION EFFECTS
RADIATIONS
RADIOSENSITIVITY
RECOVERY
REPAIR
SOLUTIONS
SURVIVAL CURVES
TIME DEPENDENCE
TUMOR CELLS
VERTEBRATES
X RADIATION