Hypoxic cell sensitizers and heavy charged-particle radiations.
Stationary-phase populations of Chinese hamster V-79 cells were irradiated with 250 kV X-rays and the Bragg peaks (spread to a width of 4 cm) of energetic He-, C-, Ne-, and A-ion beams produced at the 184-inch cyclotron and BEVALAC at Lawrence Berkeley Laboratory. Survival curves were generated with each radiation for cells suspended in air-saturated and nitrogen-saturated medium with and without sensitizer present. The oxygen enhancement ratios (OERs) measured for X-rays with 1mM metronidazole and 0.5 mM misonidazole were 2.0 and 1.6 respectively. The OERs without sensitizer for He-, C-, Ne-, and A-ion Bragg peaks were 2.4, 1.7, 1.6 and 1.4 respectively. For each type of radiation tested the presence of hypoxic-cell sensitizers resulted in an additional reduction in the measured OERs, indicating that these drugs should be of benefit in the radiotherapy planned with these and other high LET radiations.
D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D002478:Cells, Cultured; D004735:Energy Transfer; D009593:Nitroimidazoles / Q000494:pharmacology; D010100:Oxygen; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology*
D009593:Nitroimidazoles; D011838:Radiation-Sensitizing Agents; D010100:Oxygen