Response of a spontaneous murine tumor to hyperthermia: factors which modify the thermal response in vivo

Journal Article · Fri Aug 01 04:00:00 EDT 1980 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3575282· OSTI ID:7056206

Urano, M; Gerweck, L E; Epstein, R; Cunningham, M; Suit, H D

Factors which may modify the thermal response of a C3Hf/Sed mouse spontaneous fibrosarcoma were studied. Hyperthermia was given in a constant-temperature water bath by immersing the mouse foot or culture flask at 43.5/sup 0/C. The pH effect was confirmed in the first experiment. Single-cell suspensions were treated at various pH in vitro and cell survival was determined by lung colony assay in vivo. The slope of the survival curve decreased with decreasing pH level without changing extrapolation numbers. To study the effect of tumor size on the thermal response, tumors of four different sizes were treated in vivo. Tumor growth analysis demonstrated that an increase of the thermal sensitivity was associated with increasing tumor volume. TCD/sub 50/, treatment time to achieve a tumor control in half the treated animals, also decreased with increasing tumor volume, i.e., 170, 141, 123, and 111 min for 35-, 100-, 270- and 800-nm/sup 3/ tumors, respectively. Comparative studies on in vivo and in vitro cell survival strongly suggested that the tumor pH decreases with tumor growth. An attempt was made to reduce blood pH by adding 15% CO/sub 2/ in the respiratory air; this resulted in slight enhancement of the thermal response. These results are discussed.

• Research Organization: Massachusetts General Hospital, Boston
• OSTI ID: 7056206
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 83:2; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

560152 -- Radiation Effects on Animals-- Animals
560205* -- Thermal Effects-- Vertebrates-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALKALI METAL ISOTOPES
ANIMAL CELLS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BIOLOGICAL MATERIALS
BLOOD
BODY FLUIDS
BODY TEMPERATURE
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CELL CULTURES
CESIUM 137
CESIUM ISOTOPES
CHALCOGENIDES
COLONY FORMATION
DATA
DISEASES
EXPERIMENTAL DATA
EXTERNAL IRRADIATION
FIBROSARCOMAS
GROWTH
HYPERTHERMIA
IN VITRO
IN VIVO
INFORMATION
IRRADIATION
ISOTOPES
MAMMALS
MATERIALS
MICE
NEOPLASMS
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
OXIDES
OXYGEN COMPOUNDS
PH VALUE
RADIOISOTOPES
RODENTS
SARCOMAS
SURVIVAL CURVES
TEMPERATURE EFFECTS
TUMOR CELLS
VERTEBRATES
WHOLE-BODY IRRADIATION
YEARS LIVING RADIOISOTOPES