The Expression Of AQP1 In Lung Injury In Rats With Severe Acute Pancreatitis And The Effect Of QingYiTang

Background: severe acute pancreatitis (SAP) is a fatal surgical disease, the disease rate is to ascend this years and the pathogenesis is not completely identify.the main pathological change is inflammatory reaction, and it could cause systemic inflammatory reaction.It often relate to other organ.such as lung,kidney and so on.clinically,75% SAP patients can be detected acute lung injury .and some patients can develop to adule respiratory distress syndrome.AQP 1,4,5distribute on pneumoangiogram and alveolar epithelium.Objective:To observe the expression and function of Aquaporin1 in lung injury in rats with SAP, and to investigate the molecular mechanism of injury of lung in SAP.Methods: SAP model was induced by retrograde infusion of 1.5% sodium deoxycholate into biliopancreatic duct of wistar rats. 120 healthy wistar rats (220g -280g) were randomly divided into 4 groups. Group I was treated with sham operation; Group II undergone SAP surgery but without any treatment; Group III with SAP surgery were treated with dexamethasone through femoral vein intubation and Group IV with Qingyitang by intragastric administration. Every 10 rats were disposed to observation in each group after corresponding treatment after 6 hours, 12 hours and 24 hours, respectively. Serum amylase (AMY) was determined by biochemical method and arterial PO₂, PCO₂ were measured at the same time. Wet/dry weight ratio of lung were calculated. Histopathological changes of lung were observed under light microscope.RT-PCR and immunohistochem- istry technique were used to detect the expression of mRNA and protein levels of AQP1, respectively.Results: (1) Compared with sham operation groups,serum AMY in SAP groups increased respectively in a time-dependent manner(P<0.01) ,. Wet/dry weight ratio of lung decreased markedly(P<0.01). The pathologic changes of lung in SAP group were edema and congestive with large of neutrial cells infiltration. Atelectasis could be observed locally. Arterial PO2 decreased significantly and the PCO₂ increased in SAP groups time depedently. (2)After treatment with dexamethasone or Qingyitang, levels of serum AMY, ascites amount and PCO2 decreased and PO2 increased,PathophySiol- ogic changes in lung relieved significantly (P<0.01, P<0.01, P<0.01). The difference were apparente between dexamethasone and Qingyitang group(P<0.05). (3) AQP1 mRNA and protein level decreased respectively in SAP group compared with that of fake surgery group(P<0.01 P<0.01). But after treatment with dexamethasone or Qingyitang, AQP1 increased signifi- cantly. There was no difference between dexamethasone and Qingyitang group(P>0.05).Conclusions:There exit lung injury associated with SAP.AQP1 mRNA and protein levels decreased in injuried lungs and increased after treatment. The results demonstrated that AQP1 may be a protective protein in SAP. with lung injury.Qingyitang is effective drug in SAP treatment.