[Expression of Cav-1, AQP1 and AQP5 in lung of acute pancreatitis-associated lung injury rats and the therapeutic role of Qingyitang].

Abstract

to investigate the expression and location of caveolin-1 (Cav-1), aquaporin 1 (AQP1) and AQP5 in the lung of acute pancreatitis-associated lung injury rats and to determine the role of these molecules in the pathologic progress and the potential therapeutic mechanisms of Qingyitang. forty Wistar rats were randomly divided into sham operation (SHAM) group, acute lung injury (ALI) group, dexamethasone (DEX) group and Qingyitang (QYT) group. ALI was induced by reverse injection of deoxycholate into biliopancreatic duct of rats. Blood and lung tissues were collected after 24 h. Serum amylase, lung wet/dry (W/D) ratio and pathological section were detected to evaluate the degree of lung injury. reverse transcription-polymerase chain reaction was taken to detect the mRNA levels of Cav-1, AQP1 and AQP5. Lipid rafts were prepared for detection of the distribution and expression level of Cav-1, AQP1 and AQP5 proteins by Western blot. the concentration of serum amylase, the value of W/D and the degree of pathological lung injury obviously increased in ALI rats. Cav-1, AQP1 and AQP5 were present in the lung while the mRNA level decreased in ALI rats. Cav-1 appeared mainly in lipid rafts and less in non-lipid rafts. AQP1 was localized to lipid rafts while AQP5 to non-lipid rafts. The localization of these three molecules in the lung of ALI rats did not change compared with SHAM rats while their protein levels decreased. Compared with ALI rats, the concentration of serum amylase, the value of W/D and the degree of pathological lung injury obviously decreased in DEX and QYT rats. The mRNA and the protein expression of Cav-1, AQP1 and AQP5 increased in various degrees by DEX or QYT treatment. Cav-1 and AQP1 are enriched in lipid rafts while AQP5 in non-lipid rafts. The down-regulated expression of these three molecules may play important role in acute pancreatitis-associated lung injury. DEX and QYT may relieve lung injury effectively by up-regulating the expressions of Cav-1, AQP1 and AQP5.