| Objective:Discussion the relationship between rat alveolar epithelial cell tight junction proteins claudin 1、3、4 and pulmonary edema after blast lung injury. Methods:Ten SD rats were randomly divided into control group and experimental group, PVC pipe and firecrackers were used to make BLI model. After 4h rats were killed and opened their anocelia, part of lung tissue was used for HE staining, immunohistochemical staining and basement membrane staining. Colloidal lanthanum electron microscopy specimens were used to observe the morphology of alveolar epithelial cells and the distribution of lanthanum. Measured the content of protein in bronchoalveolar lavage fluid by UV spectrophotometry. The average gray value of claudin 1、3、4 were measured by image analysis software was used to represent protein expression.L2 cells were randomly divided into experimental and control groups(n=6), then experimental group were under high pressure gas 50 ms, and after 2h gauged claudin protein content and monolayer permeability. Designed and selected efficient si RNA and L2 cells were randomly divided into claudin1, claudin3 and claudin4 groups. Claudin1, claudin3 and claudin4 groups were randomly divided into experimental and control groups(n=6), and experimental groups were interfering claudin1, claudin3 and claudin4 protein expression with the corresponding si RNA. After 6h gauged claudin protein content, monolayer permeability and done immunofluorescence. Results:After the explosion of firecrackers, rats were rapid shallow breathing and pink exudate was leaked from nose and mouse. Generally see lung is anthorisma, has a kermesinus and the surface have different sizes of haemorrhage point. Light microscope showed that there are a large number of inflammatory cells and red blood ceels are in alveolar space. Electron microscope showed a large number of lanthanum are in alveolar interval. While the control group did not see obvious anomalies. Compared with control group the expression of claudin 1、3、4 was decreased, lung fluid was increased and protein leaked significantly in experimental group.Compared with control group, after high pressure gas impacted the Evans blue clearance rate increased and claudin3 and claudin4 content decreased. After si RNA interference the Evans blue clearance rate increased in claudin3 and claudin4 groups, claudin1, claudin3 and claudin4 content all decresed. And immunofluorescence staining showed that each target proteins were only expressed on the cell membrane. Conclusion:After BLI the expression of tight junction protein was decreased and the expression of claudin 1、3、4 are negatively correlated with degree of BLI. And claudin3,4 play a key role in the tight junction function changes, the protein content changes lead to changes in epithelial permeability. The expression of tight junction protein is closely related to the occurrence and development of pulmonary edema after BLI. |
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