角叉菜胶致炎症性胸腔积液大鼠胸膜上水通道蛋白1的表达

Expression of aquaporin-1 in rat model of carrageenan-induced pleural effusion

目的探讨水通道蛋白1(AQP-1)在炎症性胸腔积液大鼠胸膜上的表达及其与胸水形成的关系。方法56只健康Wistar大鼠随机分为对照组(8只)和胸膜炎组(48只)。采用角叉菜胶胸腔内注射复制炎症性胸腔积液大鼠模型。胸膜炎组根据注入角叉菜胶后处理时间再分为6、12、24、36、48和72h组,每组8只。测定各组大鼠胸腔积液量,对胸腔积液进行细胞计数和分类,采用HE染色观察脏、壁层胸膜的病理变化,采用免疫组化染色检测AQP-1在大鼠胸膜上的分布,分别采用RT-PCR和Westernblot方法检测脏、壁层胸膜AQP-1的mRNA和蛋白表达。结果胸膜炎各时相组胸水量分别为(2.10±0.22)mL、(4.10±0.15)mL、(4.40±0.36)mL、(3.20±0.27)mL、(2.60±0.18)mL和(0.12±0.02)mL。AQP-1主要表达在脏、壁层胸膜的间皮细胞和毛细血管内皮细胞。胸膜炎各时相组脏、壁层胸膜AQP-1表达均增强。胸膜炎组AQP-1mRNA在壁层胸膜的表达于6h开始升高,24h达高峰;在脏层胸膜的表达于12h开始升高,24h达高峰。AQP-1蛋白表达的变化趋势与mRNA表达一致。12h和24h组壁层胸膜AQP-1表达与胸腔积液量呈正相关(r=0.857,r=0.846,P均<0.01);24h脏层胸膜AQP-1表达与胸腔积液量呈正相关(r=0.725,P<0.05)。结论胸膜炎胸腔积液时胸膜AQP-1表达增强,AQP-1可能参与炎症性胸腔积液的转运过程。

Objective To investigate the expression of aquaporin-1（AQP-1） on pleura in rats with carrageenan-induced pleural effusion and explore the role of AQP-1 in effusion formation.Methods Fifty-six healthy Wistar rats were randomly divided into a normal control group and 6 pleuritis groups（6,12,24,36,48 and 72 h groups respectively）.The rat model of inflammatory pleurisy was induced by injecting λ-Carrageenan into the pleural cavity.The expression of AQP-1 on pleura was detected with immunohistochemistry.The mRNA and protein expression of AQP-1 on visceral pleura and parietal pleura were measured by RT-PCR and Western blot assay respectively.The volume of pleural effusions were measured.Results The volume of pleural effusion was（2.10±0.22）mL,（4.10±0.15）mL,（4.40±0.36）mL,（3.20±0.27）mL,（2.60±0.18）mL,（0.12±0.02）mL in the 6,12,24,36,48 and 72 h pleuritis groups respectively.AQP-1 were mainly expressed on visceral and parietal pleural mesothelial cells and capillary endothelial cells,and significantly increased in all pleuritic rats.The mRNA and protein expression of AQP-1 on parietal pleura increased after 6 h and reached peak level at 24 h in pleuritic groups.The mRNA and protein expression of AQP-1 on visceral pleura increased after 12 h and reached peak level at 24 h in pleuritic groups.The expression of AQP-1 on parietal pleura at 12 h and 24 h in pleuritic groups was correlated positively with the volume of pleural effusion（r=0.857,r=0.846,all P〈0.01）.The expression of AQP-1 on visceral pleura at 24 h in pleuritic groups was positively correlated with the volume of pleural effusion（r=0.725,P〈0.05）.Conclusions The expression of AQP-1 on pleura were increased in rats with carrageenan-induced pleural effusion.AQP-1 may play a role in pleural fluid transportation in pleural effusion.