Effects of Glycerol and of Anoxia on the Radiosensitivity of Haploid Yeasts to Densely Ionizing Particles

Abstract

The radiosensitivity of haploid yeast (Saccharomyces cerevisiae) was measured over the range of linear energy transfer (LET) from 20 Mev gm-1 cm2 to 5500 Mev gm-1 cm2 under four sets of conditions: (1) air atmosphere in buffer solution, (2) N2 atmosphere in buffer solution, (3) air atmosphere in 6 M glycerol solution, and (4) N2 atmosphere in 6 M glycerol solution. Treatment with 6 M glycerol protected cells irradiated in anoxia by an additional factor of about 1.9 throughout the range of LET studied. The kinetics of this effect were studied. The maximum protective effect was not seen until the cells had been exposed to glycerol for about 10 minutes, whereas the water was apparently removed much faster. The results are discussed in relation to current models of radiobiological action.