Common Biliopancreatic Duct Research Articles

Tumor Necrosis Factor Alpha Preconditioned Umbilical Cord Mesenchymal Stem Cell-Derived Extracellular Vesicles Enhance the Inhibition of Necroptosis of Acinar cells in Severe Acute Pancreatitis.

Severe acute pancreatitis (SAP) is a common abdominal emergency with a high mortality rate and a lack of effective therapeutic options. Although mesenchymal stem cell (MSC) transplantation is a potential treatment for SAP, the mechanism remains unclear. It has been suggested that MSCs may act mainly through paracrine effects; therefore, we aimed to demonstrate the therapeutic efficacy of extracellular vesicles (EVs) derived from human umbilical cord mesenchymal stem cells (UCMSCs) for SAP. Na-taurocholate was used to induce a rat SAP model through retrograde injection into the common biliopancreatic duct. After 72 h of EVs transplantation, pancreatic pathological damage was alleviated, along with a decrease in serum amylase activity and pro-inflammatory cytokine levels. Interestingly, when UCMSCs were preconditioned with 10 ng/mL tumor necrosis factor alpha (TNF-α) for 48 h, the obtained EVs (named TNF-α-EVs) performed an enhanced efficacy. Furthermore, both animal and cellular experiments showed that TNF-α-EVs alleviated the necroptosis of acinar cells of SAP through RIPK3/MLKL axis. In conclusion, our study demonstrated that TNF-α-EVs were able to enhance the therapeutic effect on SAP by inhibiting necroptosis compared to normal EVs. This study heralds that TNF-α-EVs may be a promising therapeutic approach for SAP in the future.

High-mobility group box-1 inhibition stabilizes intestinal permeability through tight junctions in experimental acute necrotizing pancreatitis.

In acute necrotizing pancreatitis (ANP), bacterial translocation (BT) from the gastrointestinal tract is the essential pathogenesis in the development of septic complications. Although high-mobility group box-1 (HMGB1) is associated with BT and organ dysfunction in ANP, the mechanism of HMGB1 in the intestinal barrier dysfunction and BT has not been well addressed. In this study, we intend to address the role of HMGB1 in ANP involving BT and intestinal barrier dysfunction. Experimental ANP was achieved in male Sprague-Dawley rats through a retrograde injection of taurocholate into the common biliopancreatic duct following a laparotomy operation. HMGB1 blockade intervention was conducted with a subcutaneous injection of anti-HMGB1 antibody immediately before the laparotomy procedure. Twenty-four hours after ANP induction, pancreatic and intestinal tissues and blood samples were collected for a histopathological assessment and lipid peroxidation or glutathione (GSH) evaluation. AP-induced barrier dysfunction was determined by an intestinal permeability assessment. Tight junction proteins and autophagy regulators were investigated by western blotting, immunohistological analysis and confocal immunofluorescence imaging. ANP developed as indicated by microscopic parenchymal necrosis and fat necrosis, which were associated with intestinal mucosal barrier dysfunction. HMGB1 inhibition played a protective role in intestinal mucosal barrier dysfunction, protected against microbiome changes in ANP, and relieved intestinal oxidative stress. Additionally, HMGB1 inhibition attenuated intestinal permeability; preserved the expression of TJs, such as claudin-2 and occludin; and decreased autophagy. Furthermore, the autophagy regulator LC3 and TJ protein claudin-2 were both upregulated in ANP according to dual immunofluorescence analysis. HMGB1 inhibition ameliorated the severity of experimental ANP though beneficial effects on BT, mainly involving in TJ function.

Ameliorative effect of certolizumab on experimentally induced acute necrotic pancreatitis in rats.

The effects of Certolizumab, a pegylated monoclonal antibody to tumor necrosis factor α, on experimentally induced acute pancreatitis (AP) were examined. Thirty-six Wistar Albino male rats were randomly divided into four groups. Group I was the control group and no medication administered to this group. Group II was the Certolizumab group, and 100 ml/kg serum physiologic administered into the biliopancreatic duct and a single dose of 10 μg Certolizumab was simultaneously administered intraperitoneally. Acute pancreatitis was induced with a retrograde injection of 3% Na taurocholate into the common biliopancreatic duct in the study (Group III) and treatment (Groups IV) groups. Rats were sacrificed 72 hours later. Serum amylase, lipase, lactate dehydrogenase activities, along with pancreatic histopathology, were examined. Certolizumab treatment significantly decreased serum amylase, lipase, and LDH levels; histopathologically edema, hemorrhage, parenchymal necrosis, fat necrosis, and infiltration scores; immunohistochemically MDA, MPO, TNF-α and Caspase-3 activity. The results support the idea that certolizumab might be beneficial for the severity of AP.

Endoscopic biliary drainage management for children with serious cholangitis caused by congenital biliary dilatation.

Congenital biliary dilatation (CBD) is usually associated with complications such as recurrent cholangitis, manifested as abdominal pain, vomiting, and jaundice. If cholangitis cannot be controlled by conservative treatment, a good therapeutic effect can be obtained through percutaneous biliary drainage or open T-tube drainage. We aimed to evaluate our experiences in biliary drainage through endoscopic retrograde cholangiopancreatography in children with cholangitis caused by CBD. From January 2014 to December 2017, 167 children with CBD were treated in our hospital. 17 patients (10.18%) with serious cholangitis caused by CBD underwent ERCP. There were 4 males and 13 females with an age range of 10-120 months (average 56.4months). Placement of a biliary stent was attempted for biliary drainage through endoscopic retrograde cholangiopancreatography. Of the 17 patients studied, 13 children had jaundice and 15 had elevated aminotransferases. ERCP showed CBD in all patients and a common biliopancreatic duct in 12 of 17 patients (70.6%). Five patients underwent nasobiliary drainage and 12 patients underwent biliary drainage through double pigtail tubes. All patients achieved successful biliary drainage. Postoperative pancreatitis occurred in one patient. Biochemical indicators decreased significantly in 12 patients (70.6%) on the second postoperative day. The average length of hospital stay after surgery was 4.5 (range 3-7) days. No major complications related to ERCP were observed and all children had a good prognosis so far. Endoscopic biliary drainage is a safe, simple, and reliable technique. It can be used to resolve CBD-associated cholangitis, evaluate the biliary tract and pancreatobiliary duct junction, and guide pediatric surgeons to choose the right time and the correct procedure for CBD.

In vitro effects of emodin on peritoneal macrophages that express membrane-bound CD14 protein in a rat model of severe acute pancreatitis/systemic inflammatory response syndrome

Emodin is the main active constituent of rhubarb and is often used in Chinese herbal medicine for the treatment of systemic inflammatory response syndrome (SIRS). The present study aimed to determine the in vitro effects of emodin on the expression of membrane-bound cluster of differentiation 14 (mCD14) protein in peritoneal macrophages (pMΦs). The severe acute pancreatitis (SAP)̸SIRS model was established in Sprague‑Dawley (SD) rats via retrograde injection of 1.5% sodium deoxycholate into the common biliopancreatic duct. The 40 SD rats were randomly divided into the sham‑operated (n=10) group (SO) and the model group (n=30). After 24 h, pMΦs were harvested and the model group was randomly divided into three subgroups (n=10 per group), the 5 µg/ml emodin group (EMO), the 0.1 µmol/ml dexamethasone group (DEX) and the SIRS/SAP group (SI). Treatment agents were administered following macrophage adhesion for 24 h. Compared with that of the SO group, the SI group showed significantly increased pathological changes (P<0.01). Compared with that of the SO group, mCD14 expression in pMΦs was significantly decreased in the SI group (P<0.01). Additionally, compared with that of the SI group, mCD14 expression in pMΦs was significantly increased in the EMO group (P<0.01) and in the DEX group (P<0.01). Compared with that of the DEX group, mCD14 expression in pMΦs was significantly increased in the EMO group (25.60±2.79 vs. 20.87±1.99; P<0.01). The pathological changes observed in the pancreas of rats in the model groups were more severe than that of the SO group. Moreover, mCD14 expression levels in pMΦs were significantly decreased in the SI group. The pathological changes of each intervention group improved to various degrees, particularly in the EMO group.

Role of endoscopic retrograde cholangiopancreatography in diagnosis and management of congenital choledochal cysts: 28 pediatric cases

Background/purposeManagement of choledochal cysts consists of surgical excision and hepaticojejunal anastomosis. Endoscopic retrograde cholangiopancreatography (ERCP) can be used to resolve complications and to evaluate the biliary tract and pancreatobiliary duct junction. Our aim was to underline the importance of ERCP for optimal management. MethodsFrom 2005 to 2011, 28 patients were reviewed (21 female, 7 male; mean age, 5.71 years; range, 2-16 years). After imaging, all patients underwent elective ERCP and were referred for surgery. ResultsCholedochal cyst was diagnosed at ultrasound and magnetic resonance cholangiopancreatography in all examined patients; common biliopancreatic duct was diagnosed in 3 (20%) of 15 patients at magnetic resonance cholangiopancreatography and in none at ultrasound. Endoscopic retrograde cholangiopancreatography showed choledochal cyst in all patients and common biliopancreatic duct in 19 (68%) of 28 patients. Twelve patients underwent sphincterotomy. All patients underwent surgical extrahepatic biliary tree resection and hepaticojejunal anastomosis. Mean period of hospitalization was 9.5 days (range, 6-13 days). No major complications related to ERCP were observed. Two patients needed postoperative ERCP for complications (pancreatitis during follow-up). ConclusionsIn our pediatric experience, ERCP is feasible and safe. It can rule out other possible biliary tract anomalies and help plan the timing and choice of the appropriate surgical procedure.

Prophylactic Glycine Administration Attenuates Pancreatic Damage and Inflammation in Experimental Acute Pancreatitis

Background/Aims: Acute pancreatitis (AP) is characterized by premature zymogen activation, systemic inflammatory response resulting in inflammatory infiltrates, sustained intracellular calcium, neurogenic inflammation and pain. The inhibitory neurotransmitter and cytoprotective amino acid glycine exerts a direct inhibitory effect on inflammatory cells, inhibits calcium influx and neuronal activation and therefore represents a putative therapeutic agent in AP. Methods: To explore the impact of glycine, mild AP was induced in rats by supramaximal cerulein stimulation (10 μg/ kg BW/h) and severe AP by retrograde injection of sodium taurocholate solution (3%) into the common biliopancreatic duct. 100/300 mmol glycine was administered intravenously before induction of AP. To elucidate the effect of glycine on AP, we determined pathomorphology, pancreatic cytokines as well as proteases, serum lipase and amylase, pancreatic and lung MPO activity and pain sensation. Results: Glycine administration resulted in a noticeable improvement of pathomorphological alterations in AP, such as a reduction of necrosis, inflammatory infiltrates and cytoplasmic vacuoles in cerulein pancreatitis. In taurocholate pancreatitis, glycine additionally diminished pancreatic cytokines and MPO activity, as well as serum lipase and amylase levels. Conclusions: Glycine reduced the severity of mild and much more of severe AP by attenuating the intrapancreatic and systemic inflammatory response. Therefore, glycine seems to be a promising tool for prophylactic treatment of AP.

Inhibition of iNOS reduces the therapeutic effects of ozone in acute necrotizing pancreatitis: An in vivo animal study

Objective. Previously, it was shown that ozone and S-methylthiourea (SMT) treatments had ameliorative effects on experimental models of acute necrotizing pancreatitis (ANP). It is possible that the combination of ozone and SMT may be more effective than either therapy. Therefore, we investigated the efficacy of combination therapy with ozone and SMT in an experimental rat model of ANP. Material and methods. Sprague-Dawley rats were divided into five experimental groups. Groups were designed as Sham-operated, ANP, ANP + Ozone, ANP + SMT and ANP + Ozone + SMT. A model of ANP was induced by injection of sodium taurocholate into the common biliopancreatic duct. Four days after induction, blood and tissue samples were obtained for biochemical, microbiological and histopathological analysis. Results. Survival rates, serum amylase, lipase and neopterin levels, tissue oxidative stress parameters, bacterial translocation and tissue injury scores were better in the ozone and SMT groups than in the ANP group. There was no bacterial translocation in the ozone-treated groups. Tissue injury scores in the ozone group were better compared to all ANP induced groups. Ozone and SMT treatment in combination did not have better biochemical, microbiological and histological data compared to ozone or SMT treatments separately in experimental ANP. Conclusions. The combination of ozone and SMT did not provide any therapeutic advantage in ANP possibly because SMT inhibited nitric oxide synthesis which was needed for ozone action.

Mechanism and dose-effect of Ginkgolide B on severe acute pancreatitis of rats

To determine the optimal dosage and mechanism of Ginkgolide B (BN52021) on severe acute pancreatitis (SAP) of rats. Seventy male Wistar rats were randomly divided into seven groups (10 for each group). Sham-operation group (SO), SAP model group (SAP), dimethyl sulfoxide (DMSO) contrast group (DMSO), and groups treated with 2.5 mg/kg BN52021 (BN1), 5 mg/kg BN52021 (BN2), 10 mg/kg BN52021 (BN3), and 20 μg/kg Sandostatin (SS). The SAP model was established in Wistar rats by injecting 5% sodium taurocholate retrogradely into the common bilio-pancreatic duct. The rats of SO, DMSO and BN52021 were injected with 0.9% NaCl, 0.5% DMSO and BN52021 through femoral vein 15 min after the operation. The SS group was injected with Sandostatin subcutaneously. All rats were anaesthetized at 6 h after operation, and venous blood was collected to determine the levels of serum amylase and phospholipase A2 (PLA₂), and pancreas tissue was harvested and stained. There was no significant difference between the SAP and DMSO groups in serum amylase level, PLA₂, ascites and pathologic score, but significant difference was found in SAP/DMSO groups compared with those in SO group (P < 0.05) and the levels of serum amylase, PLA₂, ascites, and pathologic score were lower in the BN1, BN2, BN3 and SS groups than in the SAP and DMSO groups (P < 0.05). However, among BN1, BN2, BN3 and SS groups, BN2 had the best effect in decreasing the levels of serum amylase and PLA₂ (P < 0.05). Expression of platelet activating factor (PAF) receptor (PAFR) mRNA and protein showed no significant difference between the SAP and DMSO groups, or among BN1, BN2, BN3 and SS groups, but there was remarkable difference between SAP/DMSO group and SO group (P < 0.05), and expression of PAFR mRNA and protein was higher in the BN1, BN2, BN3 and SS groups than in the SAP and DMSO groups (P < 0.05). PAFR expression was observed in the nucleus and cytoplasm of pancreatic islet cells in Wistar rats by immunohistochemistry. By iv injection, 5 mg/kg of BN52021 is the optimal dosage for SAP rats. BN52021 may inhibit the interaction/binding of PAF with PAFR.

Ameliorative Effect of Adalimumab on Experimentally Induced Acute Pancreatitis in Rats

In this study, the effects of adalimumab (ADA), a fully humanized IgG1 monoclonal antibody to tumor necrosis factor α, on experimentally acute pancreatitis (AP) were examined. Healthy Wistar rats (n = 32) were randomly divided into 4 groups: group 1, AP; group 2, AP + ADA; group 3, control (physiologic saline), and group 4, physiologic saline + ADA (n = 8/group). Acute pancreatitis was induced with a retrograde injection of 3% sodium (Na)-taurocholate into the common biliopancreatic duct. Adalimumab was simultaneously administered at 50 mg/kg intraperitoneally for groups 2 and 4. Physiologic saline was administered instead of Na-taurocholate for non-AP groups. After 24 hours, serum amylase, lactate dehydrogenase, pancreatic myeloperoxidase, and malondialdehyde activities, along with pancreatic histopathology, were examined. Adalimumab treatment significantly decreased serum amylase activity (AP, 2778.25 ± 298.80; AP + ADA, 2143.13 ± 221.69; control, 1541.00 ± 148.39; ADA, 1143.00 ± 256.30 U/L; P < 0.001), lactate dehydrogenase activity (AP, 2978.37 ± 364.65; AP + ADA, 2582.75 ± 164.23; control 931.25 ± 135.93; ADA, 582.62 ± 99.37 U/L; P < 0.001), myeloperoxidase activity (AP, 1.44 ± 0.20; AP + ADA, 0.86 ± 0.01; control, 0.60 ± 0.17; ADA, 0.41 ± 0.00 U/g of wet tissue; P < 0.001), malondialdehyde activity (AP, 16.94 ± 3.98; AP + ADA, 7.66 ± 2.27; control, 9.07 ± 1.00; ADA, 3.58 ± 0.30 nmol/g; P < 0.01), and total histopathologic scores (AP, 2.75 ± 0.16; AP + ADA, 1.50 ± 0.19; control, 0.00 ± 0.00; ADA, 0.00 ± 0.00; P < 0.001). These results support the idea that adalimumab might be beneficial for severity of AP.

Poly (ADP-ribose) Polimerase (PARP) Inhibition in Experimental Acute Necrotizing Pancreatitis

Purpose: Inhibition of poly (ADP-ribose) polimerase (PARP) is shown to reduce inflammation in several entities. Thus, we designed a study to evaluate the efficacy of benzamide (B), a PARP inhibitor, in an experimental model of acute necrotizing pancreatitis (ANP). Methods: Thirty Sprague-Dawley rats were divided into 3 groups: sham, ANP, ANP+B groups. ANP was induced by infusing of 1 mL/kg of 3% sodium taurocholate into the common biliopancreatic duct. ANP+B group received 100 mg/kg/day benzamide i.p. for a total of 3 days after induction of ANP. The surviving animals were killed at the 4th day and their pancreas was harvested for biochemical, microbiological and histopathological analysis. Blood samples from animals were also obtained. Results: In the ANP group, a clear increase in serum amylase and neopterin levels and tissue oxidative stress indices were present; almost all of these changes were found to be reversed near to their normal values in ANP+B group. Histopathologic injury scores were significantly high in ANP group (p<0.05, ANP vs. sham) which were significantly lower in ANP+B group (p<0.05, ANP+B vs. ANP). Evaluation of bacterial translocation presented significantly less infected sites in ANP+B group than in ANP animals (p<0.01). Conclusion: Our data showed that inhibition of PARP with benzamide reduced the severity, the mortality, bacterial translocation rates and neopterin levels in the experimental ANP model of rats.Figure

Poly(ADP-ribose) polymerase inhibition modulates experimental acute necrotizing pancreatitis-induced oxidative stress, bacterial translocation and neopterin concentrations in rats

Various studies have been performed to find out novel treatment strategies for acute necrotizing pancreatitis (ANP). Inhibition of poly(ADP-ribose) polymerase (PARP) is shown to reduce inflammation in several pathological conditions. We aimed to evaluate the efficacy of benzamide, a PARP inhibitor, in an experimental model of ANP. Thirty Sprague-Dawley rats were divided into three groups: sham-operated, ANP and ANP + benzamide groups. All groups except the sham-operated group were subjected to the ANP procedure, induced by infusing of 1 mL/kg of 3% sodium taurocholate into the common biliopancreatic duct. The ANP + benzamide group received 100 mg/kg/day benzamide intraperitoneally for a total of three days after induction of pancreatitis. The surviving animals were killed at the fourth day and the pancreas was harvested for biochemical, microbiological and histological analysis. Blood samples were also obtained from the animals. In the ANP group, a significant increase was observed in concentrations of serum amylase and neopterin and tissue oxidative stress indices (malondialdehyde, superoxide dismutase and glutathione peroxidase). Almost all of these changes were found to be reversed to near their normal values in the ANP + benzamide group. Histological injury scores were significantly higher in the ANP group than in the sham group (P < 0.05, ANP versus sham), and were significantly lower in the ANP + benzamide group than in the ANP group (P < 0.05, ANP + benzamide versus ANP). Evaluation of bacterial translocation identified significantly fewer infected sites in the ANP + benzamide group than in the ANP animals (P < 0.01). We observed that inhibition of PARP with benzamide reduced the severity, the mortality, the bacterial translocation rates and the neopterin concentrations in an experimental ANP model in rats. These findings suggest that it may be possible to improve the outcome of ANP by using PARP inhibitors.

Poly (ADP‐ribose) Polimerase (PARP) Inhibition in Experimental Acute Necrotizing Pancreatitis

IntroductionInhibition of poly(ADP‐ribose) polimerase (PARP) is shown to reduce inflammation in several entities. Thus, we designed a study to evaluate the efficacy of benzamide (B), a PARP inhibitor, in an experimental model of ANP.MethodsThirty Sprague‐Dawley rats were divided into 3 groups: sham, ANP, ANP+B groups. ANP was induced by infusing of 1 mL/kg of 3% sodium taurocholate into the common biliopancreatic duct. ANP+B group received 100 mg/kg/day benzamide i.p. for a total of 3 days after induction of ANP. The surviving animals were killed at the 4th day and their pancreas was harvested for biochemical, microbiological and histopathological analysis. Blood samples from animals were also obtained.ResultsIn the ANP group, a clear increase in serum amylase and neopterin levels and tissue oxidative stress indices were present; almost all of these changes were found to be reversed near to their normal values in ANP+B group. Histopathologic injury scores were significantly high in ANP group (p&lt;0.05, ANP vs. sham) which were significantly lower in ANP+B group (p&lt;0.05, ANP+B vs. ANP). Evaluation of bacterial translocation presented significantly less infected sites in ANP+B group than in ANP animals (p&lt;0.01).ConclusionOur data showed that inhibition of PARP with benzamide reduced the severity, the mortality, bacterial translocation rates and neopterin levels in the experimental ANP model of rats.

Leflunomide

Nuclear factor-kappaB (NF-kappaB) is a potent mediator in several steps of acute pancreatitis. Leflunomide is a novel immunomodulating drug that is also a potent inhibitor of NF-kappaB activation. The aim of this study was to investigate the effects of leflunomide pretreatment in severe necrotizing pancreatitis in rats. Fifty rats were randomly divided into 5 groups. Severe necrotizing pancreatitis was induced by retrograde injection of 3% sodium taurocholate into the common biliopancreatic duct. Leflunomide (10 mg/kg) was given intragastrically for 2 doses before the experiment. Serum amylase activity, pancreatic histopathologic condition, malondialdehyde level, myeloperoxidase enzyme activity, nitric oxide level, and pulmonary changes were assessed. Leflunomide pretreatment significantly ameliorated pancreatic hemorrhage, edema, and neutrophil infiltration and decreased histopathological score compared with the untreated severe necrotizing pancreatitis group (pathological score [mean +/- SEM]: 6.70 +/- 1.19 vs 12.36 +/- 1.08 in the leflunomide treated and untreated groups, respectively, P < 0.01). Pulmonary changes was decreased in the leflunomide treated group (3.90 +/- 0.45 vs 4.75 +/- 0.25, respectively). Change in pulmonary alveolar distention was significant. Although serum amylase levels also decreased, the difference was not significant (5922 +/- 3290 vs 15547 +/- 5090 U/mL). Leflunomide is a beneficial agent in the severe form of acute pancreatitis in rats and should be considered as a potential agent for treatment of acute pancreatitis.

Efficacy of Hyperbaric Oxygen Therapy and Medical Ozone Therapy in Experimental Acute Necrotizing Pancreatitis

Our aims were to evaluate the efficacy of ozone therapy (OT) in an experimental rat model of acute necrotizing pancreatitis (ANP) and to compare its effects with hyperbaric oxygen (HBO) therapy in this entity. Forty Sprague-Dawley rats were divided into sham-operated, ANP, ANP + HBO, and ANP + OT groups. Acute necrotizing pancreatitis was induced by infusing 1-mL/kg 3% sodium taurocholate into the common biliopancreatic duct. Hyperbaric oxygen was administered twice daily at a 2.8-atm pressure for 90 minutes. Ozone therapy was set as daily intraperitoneal injections of 0.7-mg/kg ozone/oxygen gas mixture. Hyperbaric oxygen and OT were continued for 3 days after the induction of ANP. The surviving animals were killed at the fourth day, and their pancreases were harvested for biochemical, microbiological, and histopathologic analyses. Serum amylase/lipase and neopterin levels and tissue oxidative stress parameters were similar to sham's values in both the ANP + HBO and the ANP + OT groups. Histopathologic injury scores were significantly lower in the treatments groups than in the ANP group. When compared with the ANP group, the number of infected rats was significantly lesser in the ANP + HBO and the ANP + OT groups. Hyperbaric oxygen and OT reduce the severity and the mortality in the experimental rat model of ANP, and a greater benefit was received for OT comparing with HBO.

Involvement of Redox-Sensitive Extracellular-Regulated Kinases in Angiotensin II-Induced Interleukin-6 Expression in Pancreatic Acinar Cells

Angiotensin II has been shown to play a role in the pathogenesis of acute pancreatitis (AP). The present investigation aimed at elucidating redox-sensitive mechanistic pathway involved in proinflammatory actions of angiotensin II during an episode of AP; in particular, the regulation of expression of cytokine interleukin (IL)-6. Exogenous angiotensin II induced IL-6 expression, activation of extracellular-regulated kinase (ERK) 1/2, and superoxide generation in pancreatic acinar cell line AR42J, which were reversed by the angiotensin II type 1 (AT(1)) receptor antagonist, losartan (2-butyl-4-chloro-1-[p-(o-1H-tetrazol-5-ylphenyl) benzyl] imidazole-5-methanol monopotassium salt, C(22)H(23)ClN(6)O). Pharmacological blockade of ERK1/2 improved angiotensin II-induced IL-6 expression. Moreover, angiotensin II-induced ERK1/2 activation was suppressed by antioxidant, indicating that redox-regulated ERK1/2 mediates the cytokine expression. cAMP-responsive element-binding protein (CREB) might be involved in ERK1/2-induced IL-6 expression because phosphorylation of CREB was observed after angiotensin II treatment, which was reversed by losartan and the ERK1/2 inhibitor. These results were in close agreement with the in vivo findings using an obstructive model of AP. Obstruction of the common biliopancreatic duct time-dependently enhanced angiotensinogen levels, which correlated well with superoxide generation, ERK1/2 and CREB phosphorylation, and subsequent IL-6 expression. It is more important that changes in these parameters were antagonized by prophylactic administration of losartan. These in vitro and in vivo results indicate that angiotensin II induces redox-regulated ERK1/2 and CREB activation, thus leading to IL-6 expression in an AT(1) receptor-mediated manner in pancreatic acinar cells during the pathogenesis of AP.

Resveratrol ameliorates hepatic injury via the mitochondrial pathway in rats with severe acute pancreatitis

To gain insight into the processes by which severe acute pancreatitis induced apoptosis takes place in the liver, and to observe the protective effect of resveratrol on hepatic injury, a rat model of severe acute pancreatitis was induced by administering 4% sodium taurocholate through the common biliopancreatic duct. Pancreatic and hepatic injury was assessed by histology. Serum ALT (alanine aminotransferase), AST (aspartate aminotransferase) and total bilirubin were determined by reaction rate assay, and the serum levels of TNF-α (tumor necrosis factor-alpha) and IL-6 (interleukin-6) were detected by ELISA (enzyme linked immunosorbent assay). We investigated cytochrome c released from mitochondria and used the RT-PCR (reverse transcription PCR), Western blot technique to evaluate Bax, Bcl-2, and caspase-3 expression levels in hepatic tissue over the time course of apoptosis. Changes in hepatic cell mitochondrial membrane potential were observed by confocal laser scanning microscopy. The majority of cytochrome c release occurred early in apoptosis from mitochondria, which undergo gradual hepatic impairment. The released cytochrome c can be reduced by resveratrol through both up-regulation of Bcl-2 and down-regulation of Bax and caspase-3. These data provide substantial evidence that apoptosis is involved in hepatic injury during the severe acute pancreatitis process and that resveratrol can ameliorate the situation, thus protecting liver function in rats with severe acute pancreatitis.

Angiotensin II Type 1 Receptor-Dependent Nuclear Factor-κB Activation-Mediated Proinflammatory Actions in a Rat Model of Obstructive Acute Pancreatitis

Angiotensin II is a key mediator of inflammation, and nuclear factor-kappaB (NF-kappaB) plays a critical role in various inflammatory diseases, including acute pancreatitis (AP). This study sought to elucidate the mechanism mediating angiotensin II involvement in angiotensin II type 1 (AT1) receptor-mediated NF-kappaB activation, and ultimately in proinflammatory actions of AP pathogenesis. A rat model of obstructive pancreatitis was induced by ligation of the common biliopancreatic duct. Pancreatic injury was determined by assessing pancreatic histology, myeloperoxidase activity, and serum interleukin-6. Protein levels of pancreatic angiotensinogen and AT1 receptor as well as NF-kappaB inhibitory subunits (IkappaBalpha and IkappaBbeta) and phospho-NF-kappaB p65, kappaB-related proteins (intercellular adhesion molecule-1, cyclooxygenase-2, and interleukin-1), and NADPH oxidase isoforms p67 and p22 were examined by Western blot. Nuclear kappaB binding activity and degree of oxidative stress were determined by electrophoretic mobility shift assay and glutathione/nitrotyrosine examination, respectively. The effects of losartan, an AT1 receptor antagonist, on NF-kappaB-mediated proinflammatory actions were also assessed. Induction of AP was associated with a time-dependent increase in pancreatic angiotensinogen levels. AT1 receptor blockade with losartan improved the pancreatic histological damage, myeloperoxidase activity, and serum interleukin-6. Losartan treatment also reduced AP-associated depletion of IkappaBbeta and elevation of phospho-NF-kappaB p65 protein expression as well as the enhanced nuclear kappaB binding activity and elevated levels of kappaB-related proteins. In addition, losartan treatment suppressed pancreatic glutathione and nitrotyrosine levels, which were consistent with decreased NADPH oxidase expression. These data provide substantial evidence that angiotensin II is involved in AT1 receptor-mediated NADPH oxidase-dependent NF-kappaB activation; thus, it might ultimately promote proinflammatory actions during AP pathogenesis.

The effect of activated protein C on experimental acute necrotizing pancreatitis

IntroductionAcute pancreatitis is a local inflammatory process that leads to a systemic inflammatory response in the majority of cases. Bacterial contamination has been estimated to occur in 30–40% of patients with necrotizing pancreatitis. Development of pancreatic necrosis depends mainly on the degree of inflammation and on the microvascular circulation of the pancreatic tissue. Activated protein C (APC) is known to inhibit coagulation and inflammation, and to promote fibrinolysis in patients with severe sepsis. We investigated the effects of APC on histopathology, bacterial translocation, and systemic inflammation in experimental acute necrotizing pancreatitis.Materials and methodForty-five male Sprague-Dawley rats were studied. Rats were randomly allocated to three groups. Acute pancreatitis was induced in group II (positive control; n = 15) and group III (treatment; n = 15) rats by retrograde injection of taurocholate into the common biliopancreatic duct. Group I rats (sham; n = 15) received an injection of normal saline into the common biliopancreatic duct to mimic a pressure effect. Group III rats were treated with intravenous APC 6 hours after induction of pancreatitis. Pancreatic tissue and blood samples were obtained from all animals for histopathological examination and assessment of amylase, tumor necrosis factor-α, and IL-6 levels in serum. Bacterial translocation to pancreas and mesenteric lymph nodes was measured.ResultsAcute pancreatitis developed in all groups apart from group I (sham), as indicated by microscopic parenchymal necrosis, fat necrosis and abundant turbid peritoneal fluid.Histopathological pancreatitis scores in the APC-treated group were lower than in positive controls (10.31 ± 0.47 versus 14.00 ± 0.52; P < 0.001). Bacterial translocation to mesenteric lymph nodes and to pancreas in the APC-treated group was significantly decreased compared with controls (P < 0.02 and P < 0.007, respectively). Serum amylase, tumor necrosis factor--α, and IL-6 levels were also significantly decreased in comparison with positive controls (P < 0.001, P < 0.04 and P < 0.001, respectively).ConclusionAPC improved the severity of pancreatic tissue histology, superinfection rates and serum markers of inflammation during the course of acute necrotizing pancreatitis.

The role of inducible nitric oxide synthase inhibitor, meropenem, and taurine in experimental acute necrotizing pancreatitis.

Translocation of bacteria from the gut is one of the most important factors in the development of septic complications and mortality in acute pancreatitis. To investigate whether S-methylisothiourea (SMT), taurine (TAU), and meropenem (MER) could effect bacterial translocation and the course of acute necrotizing pancreatitis. Seventy male Sprague-Dawley rats were studied. Rats were randomly allocated into seven groups. Acute pancreatitis was induced in group II (MER), group III (TAU), group IV (TAU + MER), group V (TAU + SMT), group VI (TAU + MER + SMT), and group VII (positive control) by retrograde injection of taurocholate into the common biliopancreatic duct. Group I rats (sham) received normal saline infusion into the common biliopancreatic duct as negative control. Rats were treated with drug combinations intraperitoneally for 48 hours after induction of pancreatitis. At the 48th hour of induction, all animals were killed, and specimens were collected. Bacterial translocation to peritoneum and pancreas in groups treated with MER were lower than in the other groups. Pancreatic tissue GSHpx and SOD levels were higher in all groups in comparison with levels in group VII. Pancreatic tissue MDA levels were also lower in all treatment groups except group II. The most favorable results were obtained in group VI (TAU + MER + SMT). Also, the lowest pathologic score between the groups in which acute pancreatitis developed was obtained in group VI. Addition of TAU and SMT to the treatment protocol for acute pancreatitis seems to improve the pathologic score and oxidative stress parameters. Also, antibiotherapy with MER decreases the risk of bacterial translocation.