Abstract: To investigate the effects of mechanical ventilation on CC10 protein levels in lung tissues of rats and the effects of CC10 on lung inflammation reactions. MethodsThirty normal Wistar rats weighing 200-250g were randomly divided into 3 groups (10 in each):the control group, the low tidal volume group (tidal volume VT=8ml／kg,　ventilation time t=4h), and the high tidal volume group (VT=40ml／kg, t=4h). After ventilation, the rats were sacrificed and the lungs were removed. Levels of CC10, TNF-α and MIP-2 were determined by ELISA. The percentage of Clara cells in the bronchiolar epithelium and PMN was determined in the broncho-alveolar lavage fluid (BALF). ResultsHigh tidal volume ventilation induced serious histopathological damage in lung tissues of rats. Both TNF-α and MIP-2 in lung tissues and PMN in BALF significantly increased in the high tidal volume group as compared with the control group and the low tidal volume group (P<0.05). The levels of CC10 in lung tissues and the percentage of Clara cells was significantly lower in the high tidal volume group than those in the control and low tidal volume groups(P<0.05), but they were not statistically different between the control and the low tidal volume groups (P>0.5). ConclusionHigh tidal volume ventilation decreases the expression of CC10 in lung tissues and increases the expressions of TNF-α,nd MIP-2, and induces heavy lung injury.

Key words: Mechanical ventilation, Lung injury, CC10