Do intracellular thiol or peroxidase levels block radiation sensitization by nitrous oxide in some E. coli strains?

Although nitrous oxide (N2O) is often a radiation sensitizer in procaryotic cells, it fails to sensitize some strains of bacteria, some yeast strains, and most eucaryotic cell lines. At present this inconsistency cannot be satisfactorily explained. The experiments here use eight strains of E. coli, some of which are not sensitized by N2O, to test the hypothesis that N2O's failure to sensitize might be based on high thiol content or on low peroxidase activity. Our data contradict those hypotheses. In addition, further data show that the strains not sensitized by N2O contain no unique cellular component or compound which blocks damage from N2O.