Effect of thermotolerance on thermal radiosensitization in hepatoma cells

Journal Article · Wed Feb 01 04:00:00 EST 1984 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3576282· OSTI ID:5147277

van Rijn, J ^[1]; van den Berg, J; Schamhart, D H.J.; van Wijk, R

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1. Academic Hospital, Free Univ., Amsterdam, Netherlands

The interaction between hyperthermia and X irradiation was determined in cultured Reuber H35 hepatoma cells with different states of thermosensitivity. Incubation at 41/sup 0/C followed by 4-Gy X rays resulted after 2 hr in a stabilization of cell survival for heat or heat plus X rays, with a maximum synergism factor of 1.6. Thermotolerance did not develop during incubation at 41.7 or 42.5/sup 0/C. When heat treatment of cells was followed by irradiation, the synergism factor for thermal radiosensitization increased with both the amount of thermal cell killing and the amount of X-ray cell killing; the influence of thermal exposure on the synergism factor was greater than that of the X-ray dose. Cells were made thermotolerant either by incubation at 42.5/sup 0/C for 30 or 60 min followed by an interval at 37/sup 0/C, or by continuous incubation at 41/sup 0/C. In both cases thermotolerance was measured by incubation at 42.5/sup 0/C. No difference was observed between the maximum thermotolerance achieved with both methods. When cells were irradiated in addition to the second heat treatment, thermal radiosensitization was strongly reduced concomitant with the decreased sensitivity to killing by heat.

• OSTI ID: 5147277
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 97:2; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

560121* -- Radiation Effects on Cells-- External Source-- (-1987)
560201 -- Thermal Effects-- Cells-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
BODY TEMPERATURE
CELL KILLING
DISEASES
ELECTROMAGNETIC RADIATION
HEPATOMAS
HYPERTHERMIA
IONIZING RADIATIONS
NEOPLASMS
RADIATIONS
RADIOINDUCTION
RADIOSENSITIVITY EFFECTS
SURVIVAL CURVES
SYNERGISM
TUMOR CELLS
X RADIATION