Abstract
Background
The pathophysiologic mechanisms of radiation-induced lung injury should be elucidated to enhance the therapeutic efficacy of radiotherapy and to manage patients exposed to serious radiation by accident. It has been suggested that pro-inflammatory cytokines play an important role in radiation-induced effect on the lung. This study was aimed to investigate changes in pro-inflammatory cytokines such as TNF-α, MIP-2, IL-1β and HMGB1, a newly recognized inflammatory mediator.
Methods
The chests of BALB/c mice were selectively irradiated with single fraction of 20 Gy and then sacrificed at indicated times. Pathologic changes in the lung were examined after H&E staining. The expression level of pro-inflammatory cytokines was evaluated by ELISA kits in lung homogenate and in serum.
Results
Radiation induced inflammatory changes and mild fibrosis in lung. Biphasic increase of TNF-α and IL-1β was found in lung homogenate at 4 hours and at 3 weeks after radiation. The elevation in the second phase tended to be more intense. However, there was no similar change in serum. MIP-2 level was slightly increased in lung homogenate at 4 hours, but not at 3 weeks. HMGB1 was increased at 3 weeks in serum while there was no significant change in lung homogenate.
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