Repair but not potentiation observed in mouse lung irradiated with neon ions.
The lungs of mice were irradiated with 1, 4, or 7 fractions of X rays or neon ions in a 4-cm spread Bragg peak. Lung function as a function of total radiation dose was tested at 7 and 12 months after irradiation by measuring the resting breathing rate in a whole-body plethysmograph. The isoeffect doses increased sequentially with X rays for 1 through 4 to 7 fractions, demonstrating repair of sublethal radiation injury as previously reported. There was also a significant increase of isoeffect dose with neon ions between 1 and 4 fractions but no further increase at 7 fractions. Thus repair instead of potentiation of radiation injury in lung clearly occurred after neon ion irradiation. The effectiveness of neon ions appeared to be closer to that of neutrons with a mean energy of 8 meV than those with a mean energy of 2.3 meV.
Department of Experimental Radiotherapy, University of Texas, M.D. Anderson Hospital and Tumor Institute, Houston 77030.
E L
EL
Travis
S B
SB
Curtis
J
J
Howard
J F
JF
Fowler
D000818:Animals; D004260:DNA Repair / Q000528:radiation effects*; D007477:Ions; D008168:Lung / Q000528:radiation effects*; D051379:Mice; D009356:Neon; D011831:Radiation Genetics
D007477:Ions; D009356:Neon