Effects of Mechanical Ventilation at Different Tidal Volumes on the Expression of TNF-α and CC16 in the Lung of Rabbits

Objective To explore the effects of mechanical ventilation at different tidal volumes on the expression of TNF-α and Clara cell secretory 16-kD protein(CC16) in the lung of rabbits.Methods Thirty healthy male rabbits were randomly divided into three groups,control group,low tidal volume group(L-TV group) and high tidal volume group(H-TV group),10 rabbits in each group.Mechanical ventilation was performed in all the groups after intubation except for control group,tidal volume was 8ml / kg in the L-TV group while 25ml / kg in the H-TV group,and other parameters in the three groups were the same.Mechanical ventilation lasted for 24 hours.Changes of arterial partial pressure of oxygen before and after experiment were observed.The levels of TNF-α and(CC16) in the lung tissues were detected by ELISA,and the wet-to-dry weight(W / D) ratio of lung tissues was calculated.Lung tissue sections were prepared for biopsies,and the histopathologic changes in the lung tissues were observed with microscope.Results The arterial partial pressure of oxygen decreased in the H-TV group compared with control group(P 0.05),the W / D ratio and TNF-α level increased in the lung tissues while CC16 level decreased(P 0.01),the corresponding indices showed no significant changes in the L-TV group(P 0.05).Lung tissue edema could be observed in the H-TV group with lung tissue biopsy.Conclusion High tidal volume mechanical ventilation produces ventilator-induced lung injury(VILI),which present the change of arterial partial pressure of oxygen,lung tissue W / D,TNF-α,and biopsy of lung pathology.CC16 in the lung tissues decreases at the same time,which indicates that CC16 may play an important role in the occurrence and development of VILI.