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

Journal Article · Fri Jul 01 04:00:00 EDT 1983 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3576074· OSTI ID:5816858

Iliakis, G; Nuesse, M

The survival of synchronously growing Ehrlich ascites tumor cells (EAT cells) was measured after x irradiation in various stages of the cell cycle. Cells at the beginning of S or in G2 + M phase showed a high level of killing, whereas cells irradiated in G1 or in the middle of S phase were more resistant. These changes resulted from a change in the survival curve shoulder width (D/sub q/) as cells passed through the cell cycle, and the mean lethal dose (D/sub 0/) remained practically unchanged (0.8 +- 0.05 Gy). When synchronization of the cell population was further sharpened using nocodazole, exponential survival curves were obtained at the beginning of S phase and at mitosis with a D/sub 0/ = 0.8 Gy. When cells (in all stages) were incubated in balanced salt solution for 6 h after irradiation, repair of potentially lethal damage (PLD) was observed, resulting in an increase in D/sub q/, while D/sub 0/ remained constant. Treatment of the cells after irradiation with either caffeine or ..beta..-arabinofuranosyladenine (..beta..-araA) or hypertonic medium resulted in an expression of PLD and reduced the D/sub q/ of the survival curve. We measured the rate of the loss of sensitivity of these treatments that we assume reflects the rate of repair of PLD. Results indicate that the shoulder width D/sub q/ of the survival curve in cells irradiated at various stages of the cell cycle results from repair of PLD. It is suggested that the variations observed in cell survival through the cell cycle might reflect variations in the final amount of PLD either repaired or expressed as the cells progress through stages of the cell cycle.

• Research Organization: Institut fuer Biophysik and Gesellschaft fuer Strahlen- und Umweltforschung, Frankfurt, Germany
• OSTI ID: 5816858
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 95:1; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

560121* -- Radiation Effects on Cells-- External Source-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ADENINES
AMINES
ANALEPTICS
ANIMAL CELLS
ANTIMETABOLITES
ASCITES TUMOR CELLS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CAFFEINE
CELL CULTURES
CELL CYCLE
CELL KILLING
CENTRAL NERVOUS SYSTEM AGENTS
DISPERSIONS
DRUGS
ELECTROMAGNETIC RADIATION
HETEROCYCLIC COMPOUNDS
HYPERTONIC SOLUTIONS
IONIZING RADIATIONS
MIXTURES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PURINES
RADIATION EFFECTS
RADIATIONS
RADIOINDUCTION
RADIOSENSITIVITY EFFECTS
RECOVERY
REPAIR
SOLUTIONS
SURVIVAL CURVES
SYNCHRONOUS CULTURES
TUMOR CELLS
X RADIATION
XANTHINES