Standard error was used and differences were considered statistically significant when values were 0.05. Results All experiments were Sarolaner successfully concluded. Cytokine levels The levels of IL-6, IL-10, PGE2, and TNF- were undetectable in the sham group. The inhibition of PGE2 production did not reduce pancreatic infection, histologic score, or mortality rate. The inhibition of PGE2 production was not able to reduce the occurrence of pancreatic infection and does not have any beneficial effect in this experimental model. Further investigations will be necessary to discover a specific inhibitor that would make it possible to develop an anti-inflammatory therapy. during the entire protocol; any fast period was observed. The experimental protocol was approved by the University of S?o Paulo Ethics Commission. All animals received care in accordance with Guide for the Care and Use of Laboratory Animals. Experimental design Animals were divided into three experimental groups: group I (sham group) C 40 rats submitted to surgical procedure without induction of AP plus intraperitoneal administration of 0.5 ml of saline; group II (pancreatitis group) C 40 rats submitted to induction of AP by sodium taurocholate injection into the pancreatic duct plus intraperitoneal administration of 0.5 ml of saline; and group III (indomethacin group) C 40 rats submitted to induction of AP by sodium taurocholate injection into the pancreatic duct plus intraperitoneal administration Sarolaner of 3 mg/kg of indomethacin. Induction of acute pancreatitis The rats were operated under aseptic conditions, using ketamine anesthesia 0.2 ml/100 g (Ketalar?). The pancreas was exteriorized through a midline abdominal incision, the proximal bile duct was clamped at the liver hilum level, and the distal bile duct was cannulated using a 19G polyethylene catheter through the duodenal wall. AP was induced by intraductal retrograde injection of 0.5 ml of 2.5% sodium taurocholate (Sigma-Chemical Company?, St Louis, MO, USA), with pressure control. COL1A2 Injection flow was 0.2 ml/min. In the sham group, sodium taurocholate injection was omitted, but the surgical procedure was identical to the other groups, including bile duct cannulation. Administration of indomethacin and saline Intraperitoneal administration of 3 mg/kg of indomethacin (Sigma-Chemical Company?) was performed after the induction of AP and the same dose was repeated each 12 h. Intraperitoneal administration of 0.5 ml of saline was performed after the induction of AP and was repeated every 12 h in groups I and II. The administration of indomethacin and saline was carried out in aseptic conditions. Levels of cytokines Blood samples were collected 2 h after the induction of AP by needle aspiration. Plasma levels of IL-6, IL-10, PGE2, and TNF- were determined by ELISA using kits provided by the manufacturing company (Biosource International Cytoscreen?) and expressed in pg/ml. After induction of AP a systemic inflammatory response is initiated and inflammatory mediators can be measured and predict the severity of inflammation. Inflammatory mediators have a very short half-life and the high levels are observed in the first hours of systemic inflammatory response. In a previous publication the authors showed that 2 h is an adequate time to measure the cytokine levels in this experimental model 16. Cultures and measurement of pancreatic infection At 24 h after induction of AP, 20 rats from each group were submitted to a midline laparotomy incision under anesthesia and tissue samples were harvested from the pancreas, mesenteric lymph nodes, and liver. All samples were weighed and homogenized and aerobic cultures were made Sarolaner using blood agar plates and MacConkey agar Sarolaner plates and expressed in colony forming units (CFU) per gram. Blood and free peritoneal fluid were sampled using sterile syringes and cultured using an automated culture system (BACTEC PEDS Plus); all positive culture were inoculated on blood agar plates and MacConkey agar plates for bacterial identification. The presence of pancreatic infection was accepted when CFU/g was 105. Histological analysis Fragments of pancreas were harvested and fixed in 10% formaldehyde solution, embedded in paraffin, sectioned, and stained with hematoxylin and eosin (H&E) for light microscopy. The inflammatory changes in the pancreas were analyzed and classified by a previous described score 17. Mortality study Twenty animals from each group were kept alive for 7 days to determine the mortality rate. These animals were maintained in individual.