The effect of the electron affinic sensitizers Ro 07-0582 and Ro 03-6156 on the survival of several E. coli mutants.
Concentration versus radiosensitizing effect curves have been determined for four E. coli strains with two nitroaromatic sensitizers. The data are consistent with a simple competition kinetic model of sensitization, and K values for Ro 07-0582 are reported. An empirical relationship, DMF=alpha o.e.r., relating the dose-modifying factor produced by a given concentration of sensitizer to the oxygen-enhancement ratio of a bacterium was found to hold for all the mutants tested for values of alpha greater than 1/o.e.r. The limiting value of alpha at high concentrations of sensitizer was 0.75. Some implications of this relationship and the limiting value of alpha are discussed.
Dose-Response Relationship, Drug↗