Changes of content and mRNA expression level of TNF-α and IL-1β in rats’ lungs after repeated exposure to +Gz

Objective: To study the changes of content of TNF-α and IL-1β in rat serum and BALF and the mRNA expression level in rat lungs after repeated exposure to +Gz, so as to investigate the mechanism of lung injure induced by acceleration. Methods: 20 male health Wistar rats were randomly divided into 4 groups （n=5）: normal control group（+1Gz）, +5Gz group, +10Gz group and +15Gz group. Using animal’s centrifuge, the profile of the centrifuge +Gz exposure was trapezoidal, in which +15Gz group lasted for 30s and the other three groups lasted for 90s respectively. All single profiles were repeated 3 times with 30min interval. The blood sample, BALF and lung tissues were taken 4h after the last centrifuge run. The contents of TNF-α and IL-1β in the serum and BALF were measured by radioimmunoassay and the mRNA expression levels in rat lungs were measured by semi-quantitative reverse transcription poly-merase chain reaction （RT-PCR）. Results: The contents of TNF-α and IL-1β in rat serum and BALF and the mRNA expression levels in the rat lungs 4h later after repeated exposure to +Gz were significantly higher than those in controls,and increased parallel with the +Gz. Conclusion: It demonstrated the inflammation mediators TNF-α and IL-1β maybe play an important role in the biological damage of rat lung induced by repeated +Gz exposure.