Modification of the action of misonidazole. II. Effect of TAN on radiosensitization

Radiosensitization by misonidazole of hypoxic mammalian cells in dilute suspension is modified by the presence of the stable free radical, TAN. The dose modifying factor (DMF) of 15mM misonidazole is 2x4 for cell inactivation, and 3x5 for the production of single-strand breaks in DNA. The presence of TAN decreases these values to 1x5 and 1x75 respectively. Possible explanations for these observations are discussed. The DMF of misonidazole for cells in pellet is not affected by TAN.