Effects Of Ulinastatin On The Expression Of CC16 In The Rat Lung In Hightidal Volume Mechanical Ventilation

ObjectiveTo explore the role of ulinastatin (UTI) in the treatment course of ventilator-induced lunginjury (VILI) by investigating the effect of UTI on expression of Clara cell secretory protein(CC16) in the lung of rats in high tidal volume mechanical ventilation.MethodsTwenty-four male Wistar rats were randomly divided into three groups: control group, hightidal volume ventilation group and UTI pretreatment group. The levels of MDA in the lung andtotal protein in bronchoalveolar lavage fluid (BALF) were measured. The expression of CC16mRNA in the lung was detected by reverse transcription polymerase chain reaction (RT-PCR).The number of Clara cells and synthesis of CC16 were detected by immunohistochemistry.Results1. The levels of MDA in lung detection:Comparing with control group, the levels of MDAin lung was highly significant in high tidal volume group and UTI pretreatment group(P<0.01);Comparing with high tidal volume group, the levels of MDA in lung was decreased significant inUTI pretreatment group(P<0.01).2. The levels of protein in BALF detection:Comparing with control group, the protein inBALF was highly significant in high tidal volume group and UTI pretreatment group(P<0.01);Comparing with high tidal volume group, the protein in BALF was decreased significant in UTIpretreatment group(P<0.01).3. CC16mRNA detection:Comparing with the control group , the expression of CC16mRNA was significantly decreased in the UTI-pretreatment group and high tidal volumeventilation group,The ratio for(0.340±0.080,1.229±0.076),(P<0.01); Comparing with hightidal volume ventilation,the expression of CC16mRNA was significantly increased in the UTIpretreatment group (P < 0.01).4. the expression of CC16 and Percentage of Clara cells detection:Comparing with thecontrol group , the expression of CC16 and Percentage of Clara cells decreased was significantlyin the UTI-pretreatment group and high tidal volume ventilation group,its average light densityvalues and positive expression rate respectively(1.103±0.056,48.832±0.826%)(0.263±0.022 ,23.705±1.688%),(P<0.01);Comparing with high tidal volume ventilation, the expression of CC16 and Percentage of Clara cells were significantly increased in theUTI-pretreatment group,(P < 0.01).5.Pathological change:No substantial changes of lung morphological were observed incontrol group.But we found that alveolar congestion,hemorrhage and infiltration or aggregationof neutrophils in airspace or vessel wall,thickness of alveolar wall membrane formation wereobserved in high tidal volume (H-VT) group.The interstitial pulmonary edema andpneumorrhagia were significantly severer in high tidal volume (H-VT) group. Apart from UTIpretreatment group ,There was more obvious pathologic alterations in (H-VT) group.Conclusion1. low expression of CC16 protein and number of Clara cells can be induced by the high tidalvolume ventilation, which can lead to the imbalance of oxidant/antioxidant system. It is one ofthe most important factors in VILI.2. Ulinastatin may effectively prevent the inflammatory process and ventilator-inducedlung injury by increasing the level of CC16 and inhibit the lipid peroxidation.