Modification of cell survival and transformation by exposure to anisotonic solutions during irradiation

C3H 10T 1/2 cells were exposed to a wide range of anisotonic NaCl solutions and were irradiated during the last few minutes of the salt treatment. Radiosensitization in terms of cell killing and transformation was observed for hypotonic NaCl treatment. Hypertonic treatment with 0.5 mol/liter NaCl also caused radiosensitization for cell killing and transformation, while extreme hypertonic treatment (1.5 mol/liter) resulted in radioprotection for both end points. Radiosensitization for both end points declined as the hypotonic treatment (0.05 mol/liter) was prolonged. To a lesser extent, a decline in radioprotection by 1.5 mol/liter treatment occurred as exposure time increased.