Objective  To explore the changes and diagnostic value of tumor necrosis factor (TNF)-α and interleukin (IL)-8 levels in rat plasma after blast injury or blast injury combined with hypoxia.   Methods  Eighty Wistar rats were randomly divided into 3 groups: the normal control group (NG

n=8)

the blast injury group (BG

n=36)

and the blast-hypoxia injury group (BHG

n=36). The rats were inflicted with blast injury by BST-Ι bio-shock tube alone in BG

or subsequently were immediately put into the hypoxic cabin (volume fraction of O

2

was 12.5%) in BHG. The rats were killed at 1

3

6 h after injury

respectively. The pathological changes of the lung tiss

ues and the water content in lung were observed with gross examination

light microscopy and electron microscopy. The changes of TNF-α and IL-8 levels in rat plasma were analyzed by ELISA.   Results  There were obvious hemorrhage and edema in the lung tissues of the injured rats. The water content in lung and the plasma levels of TNF-α and IL-8 were obviously increased in BG and BHG as compared to NG (P0.01)

and the content of TNF-α and IL-8 in blood plasma was higher in BHG than that in BG at 6 h (P0.05).   Conclusion  Blast injury combined with hypoxia can significantly increase the levels of TNF-α and IL-8 in rat plasma that are in consistent with the severity of lung injury.