The effects of low-dose X-irradiation on the oxidative burst in stimulated macrophages.
OBJECTIVE
Local irradiation with a dose of around 0.5 Gy is an effective treatment of acute necrotizing inflammations. The hypothesis that low doses of X-rays modulate the oxidative burst in activated macrophages, which plays a major role in the acute inflammatory process, was tested.


METHODS
Murine RAW 264.7 macrophages were stimulated with LPS/gammaIFN, PMA or zymosan and oxidative burst was measured using either DCFH-DA or by reduction of cytochrome-C. Radiation doses of 0.3-10 Gy were given shortly before or after stimulation.


RESULTS
Low X-ray doses of <1 Gy significantly reduced the oxidative burst in activated macrophages, whereas higher doses had little effect on oxidative burst.


CONCLUSIONS
The modulation of oxidative burst by low radiation doses may contribute to the therapeutic effectiveness of low-dose radiotherapy of acute necrotizing inflammations.
Schaue
D
D
Gray Cancer Institute, Northwood, UK.
Marples
B
B
Trott
K R
KR
D000818:Animals; D002460:Cell Line; D004307:Dose-Response Relationship, Radiation; D007371:Interferon-gamma / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000378:metabolism / Q000528:radiation effects*; D051379:Mice; D019255:NADPH Oxidases / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis; D016897:Respiratory Burst / Q000528:radiation effects*; D013481:Superoxides / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014965:X-Rays
D008070:Lipopolysaccharides; D013481:Superoxides; D009569:Nitric Oxide; D007371:Interferon-gamma; D019255:NADPH Oxidases; D013755:Tetradecanoylphorbol Acetate