Effects And Mechanisms Of Hyperlipidemia On The Severity Of Severe Acute Pancreatitis In Rats

Objective: To investigate the influence of hyperlipemia in severe acute pancreatitis SAP, the expressinn of Peroxisome Proliferater Activated Receptor Gamma(PPAR-γ) and to discuss its significance in rats with SAP and SAP associate with hyperlipemia.Methods: 40 healthy male Sprague-Dawley rats, weighing 120-150g. were randomly divided into four groups : control group (C group), acute pancreatitis group (SAP group,n=10;hyperlipidemia group (TG group.n=10), acute pancreatitis associated with hyperlipidemia group(SAP-TG group,n=10). SAP group and control group:balance feed for 4 weeks; TG group and SAP-TG group:high fat feed for 4 weeks.Four weeks later, control group and TG group were sacrificed. Blood sample, pancreatic tissues and lung tissues were collected.We used AEROSET automatic biochemical analyzer to inspection triglyceride.The expression of PPAR-γwas inspected by RT-PCR test. SAP modle was induced by injection of 5% sterile sodium taurocholate into biliopancreatic duct. Rats were sacrificed at 6 hours after the onset of operation.Blood sample and pancreatic tissues were collected and the expresion of MDA in blood was examined by TBA method ; Measuring the amount of ascites by dry gauze % (ascites weight g /body weight g×100%); With part of pancreatic tissues,PPAR-γexpression was detected by RT-PCR. We put pancreatic tissues in 10% neutral formalin-fixed and took pancreatic tissue sent for histopathologic examination,and HE staining. Schmidt scoring method was used to evaluate pancreatic pathology. Results:1. lipid changes : After 4 weeks of high-fat diet, rats TG triglyceride levels were significantly increased. The difference was significant(P<0.05);2. PPAR-γexpression in pancreas and lung tissues: Compared with group C, expression of PPAR-gamma in group TG and group SAP were increased, the difference was significant (P <0.05); Compared with group SAP, expression of PPAR-γin group SAP-TG decreased,the difference was also significant (P<0.05);3. MDA content:Compared with group SAP, MDA content in group SAP-TG was significantly higher. The difference was significant (p <0.05);4.pancreatic ascites (%) : Compared with group SAP, pancreatic ascites (%) of group SAP-TG increased, the difference was significant (p <0.05);5. Pancreatic pathology grade : Compared with group SAP, inflammatory pathology scores of group SAP-TG increased significantly.The difference was significant (p <0.05).Conclusion:1.Hyperlipemia can reduce the inflammation of acute pancreatitis.2.The decrease of PPAR-γmay be one of the reasons that hyperlipidemia add the inflammation of severe acute pancreatitis.