Characterization and properties of repair of potentially lethal damage as measured with the help of. beta. -arabinofuranosyladenine in plateau-phase EAT cells

Journal Article · Wed Apr 01 04:00:00 EST 1981 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3575600· OSTI ID:6566704

Iliakis, G

..beta..-Arabinofuranosyladenine (..beta..-araA) strongly inhibits repair of PLD in plateau-phase Ehrlich ascites tumor (EAT) cells. This inhibition resulted in an exponential survival curve when 120 ..mu..M ..beta..-araA was given shortly before irradiation, but ..beta..-araA had no significant effects on survival when added 12 h after irradiation. The kinetics of repair of PLD were measured by adding ..beta..-araA at certain intervals after irradiation in either fresh or conditioned medium to separate the PLD repaired under these two growth conditions. The relative decrease in cells with potentially lethal damage as a function of the repair time (t/sub rep/) yielded a shouldered curve. This shoulder appeared to increase with increasing dose. An activation energy of 27,500 J/mole was estimated from these data. PLD repair seemed also to be inhibited at the hyperthermic temperature of 41/sup 0/C. This repair inhibition, together with a concomitant temperature-dependent fixation of PLD, is proposed to explain the effects of heat on the radiation sensitivity of cells. Protein synthesis inhibition by cycloheximide only slightly influenced the repair of PLD and then only when the drug was given to the cells 24 h before irradiation. This result indicates a low repair enzyme turnover and/or a well-supplied enzyme pool.

• Research Organization: Institut fuer Biophysik und Gesellschaft fuer Strahlen und Umweltforschung, Frankfurt, Germany
• OSTI ID: 6566704
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 86:1; 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.
ACTIVATION ENERGY
ADENINES
AMINES
ANIMAL CELLS
ANTI-INFECTIVE AGENTS
ANTIBIOTICS
ANTIMETABOLITES
ASCITES TUMOR CELLS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
BIOSYNTHESIS
BODY TEMPERATURE
CYCLOHEXIMIDE
DRUGS
EHRLICH ASCITES TUMOR
ELECTROMAGNETIC RADIATION
ENERGY
EXPERIMENTAL NEOPLASMS
FUNGICIDES
HETEROCYCLIC COMPOUNDS
HYPERTHERMIA
INHIBITION
IONIZING RADIATIONS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PESTICIDES
PROTEINS
PURINES
RADIATIONS
RECOVERY
REPAIR
SURVIVAL CURVES
SYNERGISM
SYNTHESIS
TUMOR CELLS
X RADIATION