Objective To investigate the deleterious effects of enterogenous endotoxemia on the course of acute pancreatitis in mice, and its possible mechanisms. Methods Sixty five C57BL/6 mice were assigned to 4 groups randomly, including acute edematous pancreatitis (AEP), lipopolysacchride (LPS), AEP plus LPS and normal control. AEP was induced by intraperitoneal injection of cerulein with a dosage of 50 ?g/kg at hourly interval for seven times under ether anesthesia. LPS was administrated via a gastric tube with a dosage of 5 mg/kg at 6 h after the first cerulein or saline injection. Serum amylase and LDH activities were measured at 12 h, 24 h, 48 h and 5 d. Pathological alteration in pancreas was studied. Expressions of Mac 1 (CD11b/CD18), P selectin, E selectin and ICAM 1 were evaluated by using inmmunohistochemical procedures. Expressions of cytokine genes were determined by means of RT PCR and Southern blot. Myeloperoxidase (MPO) activity in pancreas was also analyzed. Results Cerulein induced a typical changes of AEP in mice, which was confirmed by pathological changes and hyperamylasemia. LPS alone didn't develop either morphological changes or biochemical alterations. However, cerulein induced AEP challenged by LPS could cause marked parenchymal necrosis and hemorrhage with significant increment of serum amylase and LDH activities. Expressions of Mac 1, P selectin, E selectin and ICAM 1 in pancreas were enhanced. Cytokine genes including TNF?,IL 1?,IL 6 and IFN? mRNA were also upregulated. MPO activity was increased. Conclusion This study suggested that enterogenous endotoxemia, which could not induce pancreatic injury per se , could induce AEP into ANP in mice. Over stimulation of neutrophils and releasing of pro inflammatory mediators might be the contributing factors.

Objective To investigate whether apoptosis of intestinal epithelial cells occurs at the early stage of acute necrotizing pancreatitis (ANP) in rats. Methods Fourty eight Spraque Dawley rats were used. ANP model of rats was induced by retro injection of 5% sodium taurocholate into biliopancreatic duct. Laparotomized animals without induction of ANP (sham operation) served as controls. The distal segment of ileum specimens were harvested at 3 h, 6 h, 12 h and 24 h after operation and the apoptosis of intestinal epithelial cells was studied by DNA gel electrophoresis, FITC conjugated annexin V and propidium iodide (PI) staining cells analyzed by Flow Cytometry (FCM) and immunohistochemical procedures (TUNEL method). Results The DNA electrophoresis showed that typical “ladder” patterns appeared at all indicated time points in ANP group, while the DNA specimens from control group presented a single chromosomal lane, except the one at 12 h. Apoptotic percentage of detached intestinal epithelial cells assayed using Annexin V kit by FCM were (53.7?3.7)%, (27.6?6.0)%, (39.0?4.8)%, (29.0?11.3)% at 3 h, 6 h, 12 h and 24 h in control group and (50.3?11.3)%, (79.7?9.2)%, (47.8?17.3)%, (49.6?9.5)% in ANP group. There was a significant difference between two groups at 6 h, P

Objective Some experimental results indicated that cyclooxygenase 2 (COX 2) was involved in the regulatory process of balance between cell apoptosis and multiplication. The present study was designed to investigate the effect of COX 2 on the course of pancreatic adenocarcinoma cell apoptosis and its possible signal pathway. Methods Apoptosis of pancreatic cancer cells (PC 3, highly expressed COX 2) induced by selective COX 2 inhibitor, Celebrex (IC 50 , 100 ?mol), was detected by using DNA gel electrophoresis, flow cytometry and electron microscopy. Expressions of apoptotic related genes mRNA, including bcl xl, bax, Survivin, were analyzed by reverse transcription polymerase chain reaction (RT PCR). Results Substantial apoptosis was induced by the treating PC 3 cells with Celebrex, as revealed by typical ladder pattern of DNA fragments under DNA electrophoresis, increment of apoptotic apportion, and apoptotic body under electron microscopy. Apoptotic inhibitory genes, bcl xl, bax, Survivin, were expressed in PC 3 cells, and were down regulated significantly by Celebrex in bcl xl and Survivin but not for bax. Conclusion Above findings suggest that the COX 2 pathway contributes to the apoptosis of pancreatic cancer cell, which may be via signal transduction of bcl xl and Survivin genes.

Objective This study was to evaluate the effects of growth hormone (GH) on cell apoptosis of intestinal epithelium in acute necrotizing pancreatitis (ANP) rats.Methods Seventy-two SD rats were divided into three groups randomly: sham operation (SO) group, ANP group, and GH treatment group. GH-treatment group received subcutaneously 0 75?U/kg of GH. At 3?h, 6?h, 12?h, and 24 ?h after induction of ANP, the small intestinal specimens were harvested and apoptosis of intestinal epithelium was studied by DNA gel electrophoresis, FCM and TUNEL method. FasL and Bax protein expressions were detected by immunohistochemistry.ResultsThe ladder pattern on DNA gel electrophoresis presented in all time points of ANP group, but only seen in GH-treated group at 3h. Apoptotic percentage significantly increased in ANP group [(50?11)%,(80?9)%,(48?17)%,(50?10)%] as compared with SO group [(54?4)%, (28?6)%, (39?5)%,(29?11)%], all P

Objective To investigate the expression and polymorphism of lipoprotein lipase (LPL) gene and their association with acute hyperlipidemic pancreatitis(HLP). Methods A total of 120 patients Were assigned to HLP group (n=20), acute pancreatitis (AP) group (n=50) and control group (n= 50). Serum levels of triglyceride (TG), cholesterol (Ch), free fatty acid (FFA), lipoprotein and apolipoprotein and serum LPL/HL activities were determined. The mRNA expressions of LPL/HL and LPL gene intron 8 polymorphisms were detected by RT-PCR and PCR-RFLP, respectively. Results The serum levels of TG, Ch, FFA and ApoE were significantly higher in HLP group than those in AP group and control group (P<0.05). The serum level of HDL was lower in HLP group than that in AP group and control group(P<0.05). The serum LPL/HL activities were significantly higher in HLP group than that in AP and control groups. The expression of LPL mRNA was up-regulated and intron 8 Hind Ⅲ H2 allele frequency was significantly inereased in the HLP group compared to control group(0.90/0.72, P<0.05). H1 allele frequency was significantly decreased in the HLP and AP groups compared to control group(0.10/0.28 and 0.14/0.28, respectively). Conclusions The high allele frequency of LPL gene intron 8 Hind H2 result in the increase of activities and expression of LPL mRNA, which exacerbate the development of HLP through changing TG metabolism such as FFA accumulation.

Objective To investigate the effects of oxidized 1-palmitoyl-2- arachidonoyl-sn- glycero-3-phosphorylcholine (OXPAPC)in LPS signal pathway and acute necrotizing pancreatitis (ANP).Methods Eighty-eight SD rats were randomly divided into two groups:ANP group and ANP treat with OXPAPC group.ANP model was induced by injecting sodium taurocholate(5%)into pancreatic duct OXPAPC group was administered with OXPAPC at 0 hours and 6 hours after model establishment.Twenty rats from each group were separated to observe mortality.The others were killed at 12 hours,24 hours,48 hours and 72 hours respectively to detect serum levels of amylase and lactate dehydrogenase (LDH).Severity of pancreatitis was evaluated by histological score system.The activity of myeloperoxidase (MPO)in pancreas was determined by zymohistochemistry.Inflammatory factors mRNA hours after treated with OXPAPC were studied by semi-quantitative RT-PCP.Intracellular proteinase were investigated by western blot.EMSA was used to testify the activity of transcriptional factors.Results The mortality in OXPAPC group was significantly than that in ANP group. Serum amylase and LDH levels at significanfiy decreased the 12 hours and 24 hours after treated with OXPAPC.Histologically,OXPAPC reduced the severity of pancreatic injury including inflammatory cell infiltration and necrosis at 12 hours,24 hours,and 48 hours.There was a significant decrease of MPO activity in OXPAPC group compared to ANP group.Levels of inflammatory factors mRNA were reduced in OXPAPC group.Intracellular proteinase were down-regulated in OXPAPC group.EMSA showed that the activity of transcriptional factors weakened.Conclusion OXPAPC can block LPS signal pathway,so it can decrease the severity of ANP.

Objectives To analyze the role and mechanisms of mast cells in the inflammation and fibrosis of 2 ,4, 6-trinitrobenzene sulfonic acid (TNBS)-induced rat pancreatic fibrosis. Methods Rats were received the aseptic instillation of TNBS in ethanol via bilo-pancreatic duct, and then injected with nedocromil sodium, a mast cell stabilizer, and compound 18/80, a mast cell activator, or saline. Rats were sacrificed respectively on 3, 7, 14, 21 or 28 days. Pancreatic inflammation and fibrosis were assessed by gross and histopathological evaluation. Pancreatic fibrosis were observed by Van Gieson. Pancreatic mast cells distribution, number and their state of activation (toluidine blue) were evaluated. The activation of pancreatic stellate cells (PSCs) were assessed by the expression of a-smooth muscle actin (?-SMA) through immunohistochemistry. The expression of angiotensin Ⅱ AT1 and AT2 receptors and transforming growth factor (TGF) ? 1 raRNA, which were the factors of fibrogenesis, were also assessed. Results Typical pancreatic fibrosis changes occurred in the model of rats received TNBS at 4th week by morphological evaluation. The positive expression of ?-SMA and TGF?1 in the pancreatic tissues were detected at day 3, especially at 4th week. The expression of angiotensin Ⅱ AT1 and AT2 receptors mRNA increased gradually in all the three groups, also especially at 4th week. Compared to the control group, there were more higher expression of ?-SMA, TGF?1, angiotensin Ⅱ AT1 and AT2 receptor in the compound 48/80 group, while there were lower expression of these proteins in the nedocromil group. Conclusions Mast cells are involved in TNBS-induced pancreatic inflammation and fibrosis in rats. After being activated, mast cells will promote the activation and proliferation of PSCs and upregulate the expression of angiotensin Ⅱ AT1 receptor and AT2 receptor, and then lead to pancreatic fibrosis gradually.

The effects of tetramethylpy-razine (TMP) on pancreatic blood flow and survival rate were studied in sodium tarocholate-in-duced acute pancreatitis (AP) in rats. The results showed that pancreatic relative blood flow and pancreatic tissue perfusion were significantly increased and the pathologic changes and survival rate were improved in TMP treated group-s. Plasma value of TXB2?6-Keto-PGF1? and platelet aggregation rate (PAR) were also mea-sured. We found that TMP could maintain the balance between TXA2 and PGI2 and lower the elevated PAR. It was suggested that TMP has therapeutic effect on AP in rats through improving pancreatic microcirculation; which was related to the maintanance of the balance between PGI2 and TXA2.

AIM To investigate the effects and possible mechanism s of Glycyrrhizin on rat pancreatic fibrosis induced by TNBS (trinitrobenzenesulfonic acid, TNBS ). METHODS Chronic pancreatitis model was induced in male Sprague -Dawley rats by injection of 2% TNBS into bile duct. All the rats were randomly divided into two groups. The rats in Glycyrrhizin intervention group were treat ed with Glycyrrhizin 8 mg?kg -1 by injection into tail vein from day 3 to day 28, while the rats in control group were administrated with same volume of saline vehicle. Ten rats in the Glycyrrhizin intervention group and eight rats in the control group wer e sacrificed on day 29, the blood was collected to determine amylase and hyaluro nic acid by enzyme dynamic and RIA method. The histological change of pancreatic tissue was evaluated by H&E stain and modified Van-Gieson stain. Mast cell in pancreas was stained by thionine blue. Expression of TGF-? 1,Collagen Ⅰ and ?-SMA in pancreas were assessed by immunohistochemistry and western blot. RESULTS In the Glycyrrhizin intervention group, the mast cell number and the percentage of degranulation decreased significantly, and the expression of ?-SMA protein also decreased compared to the control group, but there was no difference in amylase or hyaluronic acid between the treatment group and the control group. In the Glycyrrhizin intervention group, inflammation and fibrosis were ameliorated and expression of collageⅠ and TGF-? 1 was also decreased significantly compared to the control group. CONCLUSION Glycyrrhizin inhibits pancreatic fibrosis in chronic pancreatitis rats induced by TNBS. This action might be related to protecting pancreatic acinus cells from being destructed by mast cell activation and inhibiting extracellular matrix synthesis stimulated by pancreatic stellate cell.

Objective To observe the activation of pancreatic stellate cells (PSC) during the formation of pancreatic fibrosis induced by the pancreatic injection of trinitrobenzene sulfonic acid (TNBS). Meanwhile, the effects of PSC-related factors, such as transforming growth factor ? 1 (TGF-? 1), collagen Ⅰ and MMP-2 on the pathogenesis of pancreatic fibrosis in rats were also evaluated. Methods Pancreatic fibrosis model in rats was induced by the injection of 2% TNBS in ethanolate-phosphate buffer solution into the pancreatic duct. The rats were sacrificed and the pancreata were removed at the 72nd hour, 3rd week, 4th week, 5th week, 6th week and 7th week after the operation respectively. Expressions of ?-smooth muscle actin (?-SMA), transforming growth factor ? 1 (TGF-? 1), collagen Ⅰ and MMP-2 were determined by either immunohistochemistry or RT-PCR, or Western blot respectively. The ultrastructure of pancreas was studied by electron microscope at different time points. Results The inflammation, swelling and necrosis were the major pathological changes of the pancreas at the early stage after the injection of 2% TNBS. Subsequently, the fibrotic manifestations such as proliferation of the fibrosis, atrophy of vesicles, deposition of collagen because prominent at the 3rd week after the operation, which peaked at 4th week. The expression of TGF-? 1 was increased significantly at the 3rd week after the operation and reached maximum at the 4th week. The expression of ?-SMA, which indicated the activation of PSC, could be detected at the 3rd week and also reached the peak value at the 4th week. After wards, it was decreased gradually. During the first 72 hours, the expression of MMP-2 mRNA was increased significantly and then was fluctuated but still higher than that in normal rats. The deposition of type Ⅰ collagen was increased in the areas of fibrotic tissues. Conclusions PSC might involve in the courses of the development and progression of TNBS induced pancreatic fibrosis in rats. This action was achieved via the activation of PSC by TGF-? 1, the production of those extracellular matrix metabolic associated enzymes such as the synthesis of collagen Ⅰ and the secretion of MMP-2.