Thermal annealment and nitric oxide effects on free radicals in x-irradiated cells.
Four kinds of radicals are identified in dry spores (Bacillus megaterium) after x-irradiation: those associated with singlet, doublet, triplet, and oxygen-complex types of spectra. The singlet, present only at low temperatures, gives rise irreversibly to the doublet at 25 degrees C. All hyperfine structure is depressed after annealment at 1000 degrees C and is lost when oxygen or nitric oxide is added. The physical results support the hypothesis that reactions of long-lived free radicals can account for the radiobiological phenomena of thermorestoration, nitric oxide protection, and latent oxygen effect.
D005609:Free Radicals; D009569:Nitric Oxide; D009584:Nitrogen / Q000494:pharmacology*; D010100:Oxygen / Q000494:pharmacology*; D011830:Radiation Effects; D013171:Spores, Bacterial; D014965:X-Rays
D005609:Free Radicals; D009569:Nitric Oxide; D009584:Nitrogen; D010100:Oxygen
NITROGEN/pharmacology; OXYGEN/pharmacology; RADIATION EFFECTS/experimental