High expression of MMP-9 in the pathogenesis of severe acute pancreatitis associated with acute lung injury

Objective To observed the expression of matrix metalloproteinase-9 in the early onset of severe acute pancreatitis associated with acute lung injury in rats and investigate its effection in lung injury.Methods Thirty-two healthy adult male SD rats were randomly divided into two groups:Control group (n =8),Severe acute pancreatitis group(n =24).Severe acute pancreatitis model was induced by retrograde inject the 4％ sodium taurocholate sodium taurocholate into the biliopancreatic duct of rats.The severe acute pancreatitis group was detected the rate of lung water content、arterial blood gas.myeloperoxidase,matrix metalloproteinase-9,histopathology of the pancreas and lung injury score under the light microscope at 3 hours,6 hours and 12 hours.The matrix metalloproteinase-9 expression was detected by immunohistochemical and the results of immunohistochemical were analysed by the Image-Pro Plus image analysis system.Control group was detected the relevant indicators at 12 hours.Results Successfully modeling,the expression of matrix metalloproteinase-9 gradually increased beginning at 3 hours,at twelve hours up to the highest value(P ＜ 0.05).The degree of lung injury,lung water content,myeloperoxidase activity,PaCO2 gradually increased(P ＜ 0.05),PaO2 decreased significantly P ＜ 0.05).Conclusions The high expression of matrix metalloproteinase-9 is important to the pathogenesis of severe acute pancreatitis associated with acute lung injury. Key words: Matrix metalloproteinase 9; Severe acute pancreatitis; Lung injury; Pathogenesis; Rats