Effect of thermotolerance on the radiosensitivity and thermosensitization of mammalian cells
The sensitivity of living cells to destruction by ionizing radiation varies markedly with the conditions under which the radiation is applied. For instance, it has been established empirically that cells whose temperature is a few degrees above optimum during irradiation a much lower survival than cells irradiated at their optimum temperature, a phenomenon called thermosensitization. On the other hand, there are indications that previous heating of the cells may actually make them less susceptible to distribution by a subsequent heat treatment and to the effects of thermosensitization. This phenomenon is known as thermotolerance. The present research was designed to investigate how thermotolerance, as produced by a priming heat treatment of 43 C for 30 min., affects the subsequent radiosensitivity and thermosensitization of mammalian cells both in vitro and in vivo. It was found that a priming heat treatment given 24 hours before a heat-plus-radiation treatment produces a small decrease in thermosensitization, as reflected in a slight increase in the threshold dose of radiation required to start killing cells. This was in the sense that the fractionation schedule in which heat plus radiation is applied to cells heated 24 hours previously requires approximately 100 rads more radiation to reduce survival to the level achieved without the previous heating. However, once the threshold was achieved thermotolerance had no effect as measured by the fraction of remaining cells killed by a given increment in the radiation dose.
- Research Organization:
- Vanderbilt Univ., Nashville, TN (USA)
- OSTI ID:
- 7170112
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ANIMAL CELLS
TEMPERATURE EFFECTS
HYPERTHERMIA
RADIOSENSITIVITY EFFECTS
CELL KILLING
DOSE-RESPONSE RELATIONSHIPS
MEA
RADIOSENSITIVITY
SURVIVAL CURVES
AMINES
BODY TEMPERATURE
DRUGS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
RADIOPROTECTIVE SUBSTANCES
THIOLS
560120* - Radiation Effects on Biochemicals
Cells
& Tissue Culture
560200 - Thermal Effects