Modification of radiation damage in CHO cells by hyperthermia at 40 and 45/sup 0/C. [X radiation]

Journal Article · Sun May 01 04:00:00 EDT 1977 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3574598· OSTI ID:7310896

Henle, K J; Leeper, D B

Low hyperthermia at 40/sup 0/C either before or after X irradiation did not alter the slope of the radiation dose-cell survival curve but reduced the D/sub q/ from 145 to 41 or to 0 rad for a pre- or postirradiation incubation period of 2 hr at 40/sup 0/C, respectively. In contrast, hyperthermia at 45/sup 0/C increased the slope of the radiation survival curve by a factor of 1.7 for a radiation pretreatment of 10 min at 45/sup 0/C, but only by 1.3 for the same treatment immediately after irradiation. The corresponding D/sub q/'s were 262 and 138 rad, respectively. A combination of 45 and 40/sup 0/C hyperthermia (10 min at 45/sup 0/C + 2 hr at 40/sup 0/C + X) resulted in a superposition of the individual effects of 45 or 40/sup 0/C hyperthermia on the radiation survival curve. In addition, the radiation survival curve was shifted downward by a factor of three due to the potentiation of 45/sup 0/C hyperthermia damage by postincubation at 40/sup 0/C. Repair of sublethal radiation damage was completely suppressed during incubation at 40 following hyperthermia at 45/sup 0/C. However, when cells were returned to 37/sup 0/C, even after 6 hr at 40 following 45/sup 0/C hyperthermia, the capacity to accumulate and repair sublethal radiation damage was immediately restored. These findings imply that the hyperthermia damage from low or high temperatures interacts differentially with radiation damage. Low hyperthermia at 40/sup 0/C may affect principally the radiation repair system, whereas 45/sup 0/C hyperthermia probably alters the radiation target more severely than the repair system.

• Research Organization: Thomas Jefferson University Hospital, Philadelphia
• OSTI ID: 7310896
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 70:2; 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.
ANIMAL CELLS
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
BODY TEMPERATURE
ELECTROMAGNETIC RADIATION
HAMSTERS
HYPERTHERMIA
IONIZING RADIATIONS
MAMMALS
RADIATION EFFECTS
RADIATIONS
RADIOSENSITIVITY EFFECTS
RECOVERY
REPAIR
RODENTS
SURVIVAL CURVES
VERTEBRATES
X RADIATION