Thermotolerance in 9L-gliosarcoma cells

Technical Report · Sat May 01 04:00:00 EDT 1982

OSTI ID:5245706

Hathaway, G W

Exposure of 9L-gliosarcoma cells to temperatures between 38/sup 0/C and 40/sup 0/C for up to 8 hr did not affect colony forming ability as compared to controls held at 37/sup 0/C. However, treatment of cell populations with these non-lethal temperatures did decrease the rate of cell killing with further exposure at 43/sup 0/C. The increased resistance (thermotolerance) to 43/sup 0/C was not attributable to selective killing with the first heat exposure. The magnitude of induced thermotolerance was dependent upon the conditioning temperature, time at the conditioning temperature and the 37/sup 0/C interval between nonlethal and lethal exposures. For equal conditioning times of 4 hr, an increase in the conditioning temperature from 37/sup 0/C to 40/sup 0/C resulted in increased thermotolerance to 43/sup 0/C. Maximum tolerance also occurred with zero interval between 40/sup 0/C and 43/sup 0/C exposures, and the T/sub 0/ decayed at the rate of .046 per hr with increasing 37/sup 0/C interval between fractionations. The kinetic values which were obtained in the sublethal studies were used to model cell inactivation for temperatures between 42/sup 0/C and 45/sup 0/C. The change in the slope of an Arrhenius plot may result from the induction of thermotolerance. At lower temperatures, tolerance is able to develop to a more significant extent as compared to 45/sup 0/C, and cell killing occurs more slowly. By using kinetic data from the heat inactivation studies, the sublethal studies, and best approximations, values for tolerance induction and cell killing rates can be obtained for temperatures between 42/sup 0/C and 45/sup 0/C. The terminal slope of the model survival curves generated from this equation is in close agreement with experimentally determined values. It appears that tolerance is a sufficient condition to account for the bending of the Arrhenius plot of cell inactivation in the 42/sup 0/C to 45/sup 0/C range. (ERB)

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5245706
• Report Number(s): LBL-12778; ON: DE82018623
• Country of Publication: United States
• Language: English

Related Subjects

550300* -- Cytology
550600 -- Medicine
560201 -- Thermal Effects-- Cells-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
BIOLOGICAL ADAPTATION
CELL KILLING
COLONY FORMATION
DISEASES
GLIOMAS
HEAT TREATMENTS
MEDIUM TEMPERATURE
NEOPLASMS
SARCOMAS
TEMPERATURE DEPENDENCE
TEMPERATURE EFFECTS
TOLERANCE
TUMOR CELLS