甲泼尼龙对肾上腺素肺水肿大鼠肺组织水通道蛋白1表达的影响

Effect of Methylprednisolone on expression of aquaporin 1 in lung tissue of pulmonary edema rats induced by adrenaline

目的观察水通道蛋白1（AQP1）在肾上腺素肺水肿（PE）大鼠肺组织表达的变化，以及甲泼尼龙（MP）对其影响。方法将50只1月龄Wister大鼠随机分为对照组、PE组、MP 10 mg/kg治疗组（MP A组）、MP 20 mg/kg治疗组（MP B组）、MP 30 mg/kg治疗组（MP C组），每组10只。对照组腹腔注射9 g/L盐水，PE组大鼠按2.7 mg/kg给予腹腔注射肾上腺素注射液（11 000）, MP各组于腹腔注射肾上腺素注射液后立即腹腔注射MP。苏木精染色观察肺组织形态学改变。测量肺湿/干质量比值（W/D）。免疫组织化学染色分析AQP1的表达和分布，实时定量－聚合酶链反应（RT－PCR）检测AQP1 mRNA的表达，Western blot测定AQP1蛋白表达水平。结果1.PE组大鼠肺部出现水泡音，呼吸节律明显增快，烦躁不安；病理见双肺体积增大，有出血，气管腔内液体较多，呈粉红色泡沫状。2.大鼠肺组织W/D：PE组（6.50±0.53）与对照组（4.59±0.36）比较差异有统计学意义（P〈0.05）。3.病理评分：PE组（3.80±0.42）与MP A组（3.30±0.48）、MP B组（2.30±0.68）和MP C组（1.20±0.42）比较，PE组显著增高，差异有统计学意义（均P〈0.05）。4.肺组织AQP1免疫组织化学测定：PE组（1.20±0.79）与对照组（4.20±1.03）比较，差异有统计学意义（P〈0.05），PE组与MP A组（5.60±1.58）、MP B组（7.00±1.33）、MP C组（9.20±1.55）比较，差异均有统计学意义（均P〈0.05）。5.AQP1 mRNA表达：PE组AQP1 mRNA表达（0.12±0.43）与对照组（0.90±0.32）比较明显降低，PE组与MP A组（0.17±0.06）、MP B组（0.39±0.13）、MP C组（0.61±0.21）比较，MP各组显著升高，差异均有统计学意义（均P〈0.05）。6.AQP1蛋白表达：PE组（0.20±0.04）较对照组（0.60±0.15）显著降低，PE组比MP各组[A组（0.32±0.04），B组（0.37±0.09），C组（0.44±0.07）]显著降低，差异均有统计学意义（均P〈0.05）。结论AQP1在肾上腺素PE大鼠肺组织表达降低；MP能显著提高AQP1表达，并可明显改善肾上腺素PE大鼠肺部渗出、出血。

ObjectiveTo observe the changes in the lung aquaporin 1 （AQP1） expression in adrenaline-induced pulmonary edema（PE）, and the effect of Methylprednisolone （MP） on its expression.MethodsFifty Wister rats of 1-month old were randomly divided into 5 groups （10 rats in each group）： control, adrenaline PE, MP A, MP B, and MP C groups, respectively.Control group animals were treated with 0.27 mL 9 g/L saline; PE group was given 2.7 mg/kg adrenaline （11 000） by intraperitoneal injection; MP A, MP B and MP C groups rats were intraperitoneally injected 10 mg/kg, 20 mg/kg, and 30 mg/kg MP intraperitoneally immediately after intraperitoneal injection of adrenaline, respectively.The morphology changes in the lungs were observed with HE staining, and lung wet/dry weight （W/D） was measured.The levels of AQP1 mRNA, AQP1 protein, and AQP1 distribution in the lung tissues were detected by using real time- polymerase chain reaction, Western blot, and immunohistochemical method.Results（1）PE group exhibited a faster breathing rate, and double lung volume increased significantly; there was a visible hemorrhagic distribution in the lung surface and cross section, endotracheal filled with white or pink foam liquid.（2） The W/D of rats in PE group was higher than that of the control group（6.50±0.53 vs.4.59±0.36, P〈0.05）. （3） Pathological grading of PE group （3.80±0.42） increased significantly compared with that of the MP A group （3.30±0.48）, MP B group （2.30±0.68） and MP C group （1.20±0.42）, and there were significant differences （all P〈 0.05）. （4） Immunohistochemistry showed that the expression of AQP1 in PE group （1.20±0.79） was reduced compared with that of the control group（4.20±1.03）, and there were significant differences （all P〈0.05）. （5） The levels of AQP1 mRNA and AQP1 protein （0.12±0.43 and 0.20±0.04） were significantly lower than those of the control group （0.90±0.32 and 0.60±0.15）, and there were significant differences （all P〈 0.05）; compared with PE group, AQP1 mRNA and AQP1 protein of each group with MP treatment showed the highest values （MP A group： 0.17±0.06 and 0.32±0.04, MP B group： 0.39±0.13 and 0.37±0.09, MP C group： 0.61±0.21 and 0.44±0.07） （all P〈 0.05）.ConclusionThe expression of AQP1 reduced in adrenaline-induced PE rats.MP could improve the expression of AQP1, and significantly ameliorate the PE and bleeding.