Effects Of Dexamethasone Combined With Anisodamine On Acute Lung Injury Induced By Seawater Aspiration In Rats And The Expression Of AQP1 And AQP5

Objective:1. To observe the lung tissues pathological changes in rats with acute lung injury induced by seawater aspiration.2. To research the expression and significance of aguaporin1 and aguaporin5 in rats with acute lung injury induced by seawater aspiration.3. Discussing the lung protective effect and the possible mechanisms on the early intervention of dexamethasone combined anisodamine after seawater drowning. Methods:A total of 50 SD healthy male rats were randomly assigned into 5 group : control group?C group, n=10?, seawater drowning group?M group, n=10?, dexamethasone treatment group?D group, n=10?, anisodamine treatment group?S group, n=10?, dexamethasone and anisodamine combined treatment group?L group, n=10?. In addition to the contro group which underwent tracheotomy and intubatton only, The seawater drowning rats model was reproduced by instilling artificial seawater?3m1/kg body weight? into the endotracheal catheter of animals. Treatment groups are respectively given intraperitoneal injection of dexamethasone 5 mg/kg or?and? anisodamine 10 mg/kg immediately after seawater drowning. Blood gas analysis was done at the different time points?0.5?1?2?4?6h after infusion? in the experiment. The changes of lung wet to dry weight ratio were measured and the pathological changes in pulmonary tissue were observed after the experiment. The contents of NF-?B and interleukin 8?IL-8? were detected by enzyme linked immunosorbent assay?ELISA?; The mRNA expression changes of AQP1?AQP5 were observed by RT-PCR and the Western Blot was used to detect the protein level of AQP1, AQP5. Results:1.Rats with acute lung injury induced by Seawater was successfully reproduced; The levels of blood PaO₂?SaO₂% and pH were obviously decreased at the time point of 0.5h after infusion and the PaCO₂ were obviously higher than normal group; pH, PaO₂, SaO₂ % of treatment group was higher than that of M group gradually after 1 h and the PaCO₂ dropped rapidly in seawater drowning group. The arterial blood gas of the treatment group was obviously improved than that of model group after 6 h?P < 0. 05?.2.W/D contrast: The M, D, S, L group of lung W/D were obviously decreased at the time point of 6h after infusion, and was significantly higher than that in the control group?P<0.05?,of which the most obviously is M group. The L group of lung W/D was lower than the group D and group S?P<0. 05?; But group D has no significant difference from group S. There were no statistically significant difference among the group D and group S?P<0. 05?.3. HE staining of lung tissue: The pulmonary interstitial hyperemia, edema, alveolar space, a large number of red blood cells exudation, neutrophils infiltration, dilation of blood capillary,thickening of alveolar walls can be observed under the light microscope in the seawater drowning group, while those changes significantly relieved in the D?S?L group, and the lung injury change of L group was the lightest above three groups. 4. Determination of ELLSA finds that the lung tissue NF-KB,IL-8 concentration of D, S, L group was obviously higher than that of C group, but significantly lower than group M, and group L compared with group D, S decreased more obviously, two compared with each other in five groups, the differences were statistically significant.5. The results of RT-PCR and WB determination showed that the expression of AQP1?5 at the mRNA and the protein level in the seawater group was significantly higher than that in control group and treatment group at the time point of 6h after infusion, of which the sharpest reduction is group L, the AQP1, 5 mRNA expression levels in D, S, L group were also elevated compared with group C. Conclusion:1. The lung tissue NF-KB, IL- 8 levels increase significantly in rats with acute lung injury induced by seawater aspiration, reminder NF-KB IL- 8 and other inflammatory factors involved in the SWD- ALI disease process. The lung injury degree and the inflammatory factor levels had significant improvement after the intervention of being given dexamethasone and?or? Anisodamine, which hints that dexamethasone and anisodamine may reduce inflammation reaction by adjusting the expression of NF-KB, IL- 8 and other inflammatory factors, so as to reduce the lung injury and improve oxygenation, and they have synergistic effects on the two drugs.2. the expression of AQP1, 5 at the mRNA and the protein level was significantly increased at the time point of 6h after infusion, suggesting the up-regulation of AQP1 and AQP5 might be participated in SWD- ALI pathophysiological process of the disease. Dexamethasone and?or? anisodamine can inhibit the up-regulation of AQP1 and AQPS, which is likely to be one of the effective mechanisms of lung protection by the dexamethasone and anisodamine in SWD- ALI.