Repair of potentially lethal damage following irradiation with x rays or cyclotron neutrons: response of the EMT-6/UW tumor system treated under various growth conditions in vitro and in vivo

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

DOI:https://doi.org/10.2307/3575439· OSTI ID:6599051

Rasey, J S; Nelson, N J

Postirradiation potentially lethal damage (PLD) repair was examined in the EMT-6/UW tumor system under a variety of in vitro and in vivo growth conditions. Following x irradiation, surviving fraction increased in fed and unfed plateau cultures if subculture and plating were delayed; in exponentially growing cultures if they were covered with depleted medium for the first 6 h postirradiation; and in tumors in vivo if excision for preparation of a cell suspension was delayed. Following irradiation with 21.5 meV (d/sup +/ ..-->.. Be) neutrons, PLD repair was measurable only in unfed plateau cultures when subculture was delayed and in exponentially growing cells exposed to depleted culture medium immediately after irradiation. In x-irradiated EMT-6/UW cells, the greatest repair capacity and the highest surviving fraction ratios were measured in unfed plateau cultures; the least repair was observed in exponentially growing cells exposed to depleted medium. Thus post-neutron repair was not limited to situations where the amount of repair of photon PLD is large. The demonstration of PLD repair in tumors irradiated in vivo with X rays and the absence of such repair after neutrons could have important implications in radiotherapy if this is a general phenomenon.

• Research Organization: Univ. of Washington, Seattle
• OSTI ID: 6599051
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 85:1; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

560121* -- Radiation Effects on Cells-- External Source-- (-1987)
560152 -- Radiation Effects on Animals-- Animals
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
BARYONS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CELL CULTURES
CELL KILLING
DISEASES
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
FAST NEUTRONS
FERMIONS
HADRONS
IN VIVO
IONIZING RADIATIONS
KINETICS
LABELLED COMPOUNDS
MAMMALS
MICE
NEOPLASMS
NEUTRONS
NUCLEONS
RADIATION EFFECTS
RADIATIONS
RADIOINDUCTION
RECOVERY
REPAIR
RODENTS
SURVIVAL CURVES
TRITIUM COMPOUNDS
TUMOR CELLS
VERTEBRATES
X RADIATION