Influence of hypoxia and acidity on thermal radiosensitization and direct heat-induced death of BP-8 sarcoma cells.
The response to heat of BP-8 murine sarcoma cells was evaluated with the 125I-iodo-deoxyuridine prelabeling technique. Euoxic and hypoxic BP-8 cells were heated in vitro at pH 7.4 vs. 6.5 at temperatures ranging from 37 degrees C to 44 degrees C. The results indicated that acute hypoxia had no effect on either heat potentiation of radiation damage or direct heat-induced death. However, lowering of media pH increased direct thermal cell death and, to a lesser extent, heat potentiation of radiation lethality. These findings suggest that the enhanced radiosensitization and heat-induced death observed in chronically hypoxic tumor populations may, at least in part, be caused by hypoxia-induced tumor acidification.
D000818:Animals; D002470:Cell Survival / Q000528:radiation effects*; D002478:Cells, Cultured; D003470:Culture Media; D005260:Female; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D051379:Mice; D008809:Mice, Inbred C3H; D008813:Mice, Inbred ICR; D010100:Oxygen; D011836:Radiation Tolerance; D012513:Sarcoma, Experimental / Q000473:pathology*
D003470:Culture Media; D010100:Oxygen