Radiation treatment of acute inflammation in mice.
OBJECTIVE
Low-dose radiotherapy (RT) has often been used effectively for the treatment of a variety of benign diseases, particularly those with acute inflammatory features. Here we report findings on radiation treatment of acute inflammation using a murine carrageenin air pouch model.


METHODS
Air pouches raised on the dorsal surface of mice were injected with lambda carrageenin and were irradiated 6 h later with doses ranging from 0-5 Gy. Treatment success was evaluated at various times thereafter by volume of exudate and number of inflammatory cells, and levels of inflammation-related cytokines tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1beta) and transforming growth factor beta-1 (TGFbeta-1), and expression of inducible nitric oxide synthase (iNOS), heme oxygenase-1 (HO-1), cyclooxygenase-2 (COX-2) and inducible heat shock protein 70 (HSP70) as determined by enzyme-linked immunosorbent assay (ELISA) and Western blotting, respectively.


RESULTS
Crude inflammatory parameters such as the amount of exudates and number of inflammatory cells remained largely unaffected by radiation or were even a slightly and transiently increased. However, the expression of iNOS was attenuated by radiation concomitant with an increase in the levels of HO-1 and HSP70. Cytokine levels varied with the radiation dose and the time point.


CONCLUSIONS
Ionizing radiation, even at low doses, functionally modulates inflammatory cells. Our findings indicate possible mechanisms as to how low-dose radiation may exert anti-inflammatory effects and provide the first evidence that heat shock proteins may be involved in this response.
Schaue
Dörthe
D
Gray Cancer Institute, Northwood, Middlesex, UK. dschaue@mednet.ucla.edu
Jahns
Jutta
J
Hildebrandt
Guido
G
Trott
Klaus-Rüdiger
KR
D000208:Acute Disease; D000818:Animals; D002351:Carrageenan; D016207:Cytokines / Q000276:immunology*; D004307:Dose-Response Relationship, Radiation; D007249:Inflammation / Q000139:chemically induced / Q000276:immunology* / Q000473:pathology / Q000532:radiotherapy*; D018836:Inflammation Mediators / Q000276:immunology*; D051379:Mice; D011879:Radiotherapy Dosage; D016896:Treatment Outcome
D016207:Cytokines; D018836:Inflammation Mediators; D002351:Carrageenan