Cyclooxygenase-2 expression of pancreatic tissues in severe acute pancreatitis in rats

Objective To study the expression of cyclooxygenase-2(COX-2) in pancreatic tissues of severe acute pancreatitis(SAP) in rats,and explore the possible role of COX-2 in the pathogenesis of the SAP. Methods Forty adult male Sprague-Dawley rats were randomly divided into SAP group(n=20) and control group(n=20). At 12h after operation,acites,serum levels of amylase activity,tumor necrosis factor-α(TNF-α),TXB 2 and 6-keto-PGF 1α and the expression of COX-2 in pancreatic tissue were detected.the pathological changes of pancreatic tissues were observed and scored under microscope;the survival rate in 72h and mortality in 24h in SAP and NC group were recorded.Results At 12h after the induction of SAP,the serum amylase activity,TNF-α,TXB 2 and 6-keto-PGF 1α were significantly higher in SAP group than those in NC group(P 0.01),the volume of ascites significantly increased in SAP group(P 0.01).Compared with the NC group,the pathological scores of pancreatic edema, inflammation,hemorrhage and necrosis in SAP rats were significantlyn increased(P 0.05).The expression of COX-2 protein in pancreatic tissue in SAP group was markedly positive,but no expresion in controll group.The mortality in SAP group was 100%,but in NC group was 0. Conclusions The expression of COX-2 and the levels of PGs were up-regulated markedly in SAP rats,these results suggested that COX-2 might play an important role in the pathogenesis of SAP through increasing the levels of PGs.