Radiation-dose dependence of the formation of micronuclei in misonidazole treated cell cultures.

The effect of misonidazole at different concentrations on the anoxic radiation sensitivity of Chinese hamster cells was investigated using the frequency of radiation induced micronuclei as criterion. The result indicates that, in a high radiation dose region, sensitization with a dose modifying factor of about 1.9 and 1.3 occurs after treatment with the substance at a concentration of 8 and 0.2 mmol/l, respectively. In a low dose region the corresponding values were 1.7 and 0.8. It was concluded that high concentration of the substance in combination with high radiation doses are most beneficial.