Acute cytotoxic effect of cyclosporin A on pancreatic acinar cells in rats. Protective effect of the synthetic protease inhibitor E3123.

This study was designed to evaluate the acute toxic effects of cyclosporin A on the exocrine pancreas and the protective effects of a new potent protease inhibitor, 4-(2-succinimidoethylthio) phenyl 4-guanidinobenzoate methanesulfonate, E3123. Cyclosporin A in a dose of 5 mg/kg.h caused a significant increase in serum amylase levels, pancreatic amylase content, and interstitial edema, suggesting that it induces exocrine pancreatic injury. Cyclosporin A also caused redistribution of cathepsin B from the lysosomal fraction to the zymogen fraction, indicating colocalization of lysosomal enzymes with pancreatic digestive enzymes. E3123 in a dose of 2 mg/kg.h prevented almost completely these changes caused by cyclosporin A. These results indicate that exocrine pancreatic injury is induced by cyclosporin A and that lysosomal enzymes play important roles in the pathogenesis of this injury and also suggest that E3123 might protect the exocrine pancreas of patients receiving cyclosporin A after organ transplantation.     

Cytoprotective effects of prostaglandins and a new potent protease inhibitor in acute pancreatitis.

The redistribution of cathepsin B, a lysosomal enzyme, from the lysosomal pellet to the zymogen pellet in the subcellular fractionation, the colocalization of cathepsin B with digestive enzyme, and increased cellular, lysosomal, and mitochondrial fragility within acinar cells have been found during the early stages of caerulein-induced acute pancreatitis in rats. In the present study, the authors investigated the protective effects of prostaglandin E1 and E2, a combined therapy of these prostaglandins, and a new, synthetic, low molecular weight protease inhibitor, ONO3307, on the exocrine pancreas in this noninvasive model of experimental pancreatitis in vivo and in vitro. Prostaglandin E2, but not E1, prevented hyperamylasemia, congestion of amylase and trypsinogen in the acinar cells, redistribution of cathepsin B, and amylase and lactate dehydrogenase discharge from the dispersed acini. It also prevented cathepsin B leakage from the lysosomes and malate dehydrogenase leakage from the mitochondria in an almost dose-dependent manner, particularly at the dose of 100 micrograms/kg/hr continuous infusion. Furthermore, the combined therapy of prostaglandin E2 with ONO3307 strongly inhibited all the parameters tested in this study. This combination therapy seems to be the most effective against secretagogue-induced pancreatic injuries. These results indicate that cellular and subcellular organellar fragility seem to be closely involved in the pathogenesis of acute pancreatitis. Prostaglandin E2 seems to have important cytoprotective effects on the biologic membranes, such as a stabilizer of lysosomal or mitochondrial membranes. In addition, these findings also suggest the crucial roles of some unknown proteases in the etiology of acute pancreatitis, and indicate the clinical effectiveness of prostaglandins and this type of low molecular weight protease inhibitor for acute pancreatitis.     

Intracellular action of an exogenous low-molecular-weight synthetic protease inhibitor, E3123, in cerulein-induced acute pancreatitis in rats

The intracellular distribution and action of a new synthetic protease inhibitor, E3123, were studied in cerulein-induced acute pancreatitis in rats. Acute pancreatitis was induced by a 4-h iv infusion of a supramaximal dose of cerulein, and was treated by prophylactic (pretreatment) or therapeutic (posttreatment) continuous administration of E3123. Pancreatic edema and hyperamylasemia were ameriolated only by prophylactic treatment. A subcellular fractionation study showed that the activities of cathepsin-B and trypsin in the zymogen granule-enriched fraction of the cerulein-pancreatitis group were remarkably increased. Both prophylactic and therapeutic treatment significantly prevented the elevation of these enzyme activities. These effects were accompanied by amelioration of pancreatic histopathological features, including intracellular vacuolization and fat necrosis. A microscopic autoradiographic study using²H-labeled E3123 showed diffuse intracellular distribution of E3123, and the radioactivity of²H-E3123 in the posttreatment group was three times greater than that in the pretreatment group. This study provides the first experimental evidence that, even when administered therapeutically, exogenous protease inhibitors are transported into pancreatic acinar cells, thereby reducing the seventy of early intracellular alterations in cerulein-induced acute pancreatitis.     

Protection by gabexate mesilate (FOY) of the exocrine pancreas in rats with acute pancreatitis induced by a supramaximal dose of caerulein

Earlier studies have reported that interstitial oedematous pancreatitis characterized by hyperamylasaemia can be seen during the early stage of stimulation of supramaximal dose of caerulein. The present study investigated the changes in both cellular and lysosomal fragility and the protective effects of a synthetic protease inhibitor gabexate mesilate (FOY) on this non-invasive model of experimental pancreatitis. The infusion of FOY (50 mg/kg/h) prevented the caerulein-induced increase in serum amylase and pancreatic oedema formation and reduced the elevated amylase content significantly. The administration of FOY with caerulein also reduced the increased lactic dehydrogenase (LDH) discharge significantly and inhibited the cathepsin B leakage from lysosomes in an in vitro incubation system. These results indicate that FOY plays its protective role at the subcellular level--that is, in lysosomes by inhibiting some proteases such as phospholipase A2. The importance of esterases in the pathogenesis of acute pancreatitis is demonstrated. This type of esterase inhibitor may be valuable clinically in the treatment of acute pancreatitis and these results also suggest the role of lysosomal fragility in the pathogenesis of progression of acute pancreatitis.     

Effect of a new synthetic protease inhibitor on beta-endorphin release during acute pancreatitis in dogs

The effect on endogenous beta-endorphins of a new synthetic protease inhibitor was studied in acute pancreatitis. Pancreatitis was induced by the injection of autologous bile mixed with trypsin into the main pancreatic duct after ligation of the accessory duct. Plasma beta-endorphin concentrations and cardiovascular function were measured. Ten dogs (control group) were given 10 ml/kg/h of lactate Ringer's solution intravenously beginning 1 h before the induction of pancreatitis and continuing throughout the experiments. Six dogs received an intravenous infusion of 3 mg/kg/h of a new synthetic protease inhibitor, E-3123 (4-(2-succinimidoethylthio)4-geranidinobenzoate methanesuLfonate), in lactate Ringer's solution soon after the induction of pancreatitis. Plasma beta-endorphin concentrations in the control group increased significantly. However, plasma beta-endorphin levels in the protease inhibitor group did not increase as in the control group. The protease inhibitor infusion improved hypotension, myocardial depression, and plasma lactate, suggesting that the inhibitory effect of the protease inhibitor on beta-endorphin release contributed to the improvement.     

Effects of acute pancreatitis on hepatic secretion of lysosomal enzymes into bile and hepatic lysosomal fragility: protective effects of a new synthetic protease inhibitor, ONO 3307.

To evaluate the effects of acute pancreatitis on hepatic function and hepatic cellular and subcellular organellar fragility, we studied 1) the hepatic secretion of lysosomal enzymes (beta-glucuronidase, beta-galactosidase, and N-acetyl-beta-glucosaminidase) into bile in the isolated perfused rat liver model; 2) the aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), and lysosomal enzyme levels in the effluent in an isolated liver model; 3) hepatic lysosomal fragility in an in vitro incubation study; and 4) protective effects of a new low molecular weight synthetic protease inhibitor, ONO 3307, against hepatic injury in doses of 2 and 5 mg/kg.h in acute pancreatitis induced by a supramaximal dose of cerulein in rats. Decreased hepatic secretion of lysosomal enzymes into bile and accelerated hepatic lysosomal fragility were observed in acute pancreatitis induced by cerulein. ONO 3307 showed a significant protective effect against this hepatic injury in acute pancreatitis, the dose of 5 mg/kg.h showing a more potent effect than the dose of 2 mg/kg.h. These results suggest that the impaired hepatic function, including depressed hepatic secretion of lysosomal enzymes, seems to be closely related to accelerated hepatic fragility and that some unknown protease, which is present in pancreatitis and is susceptible to inhibition by ONO 3307, plays a crucial pathologic role in the development of this liver injury during acute pancreatitis.     

Protective effect of nafamostat mesilate on cellular and lysosomal fragility of acinar cells in rat cerulein pancreatitis.

This in vivo and in vitro study demonstrates the protective effects of a new synthetic protease inhibitor--nafamostat mesilate, FUT-175--on increased cellular and lysosomal fragility within acinar cells during the early stage of cerulein-induced acute pancreatitis in rats. FUT-175 prevented hyperamylasemia, pancreatic edema, congestion owing to amylase, and lactic dehydrogenase (LDH) discharge from acini as well as cathepsin-B leakage from lysosomes dose-dependently in doses of 1-10 mg/kg.h. These results suggest that FUT-175 can protect against pancreatitis at subcellular levels in lysosomes and cellular or organelle membranes. Proteases may well play the important role in the pathogenesis of acute pancreatitis, and such a low molecular protease inhibitor may be useful clinically in the treatment of acute pancreatitis.     

The therapeutic effect of a new synthetic protease inhibitor (E-3123) on hemodynamic changes during experimental acute pancreatitis in dogs

The therapeutic effect of a new synthetic protease inhibitor on hemodynamic changes was studied in experimental acute pancreatitis. Pancreatitis was induced by the injection of autologous bile mixed with trypsin into the main pancreatic duct after ligating the accessory duct. Plasma beta-endorphin concentrations and cardiovascular function were measured. Seventeen dogs (control group) were given 10 ml/kg/hr of lactate Ringer’s solution intravenously 1 hr before the induction of pancreatitis and throughout the experiment. Seven dogs (the low protease inhibitor group) were given an intravenous bolus injection of 0.4mg/kg of a new synthetic protease inhibitor, E-3123 (4-(2-succiminido-ethylthio)4-geranidinobenzoate methanesulfate) 30 min after the induction of pancreatitis and then a continuous intravenous infusion at 3 Μg/kg/min throughout the experiment. Seven dogs (the high protease inhibitor group) received an intravenous bolus injection of 3 mg/kg and a continuous intravenous infusion at 50 Μg/kg/min of E-3123 according to the same method as in the low protease inhibitor group. The mortality rate during the experiment was 41% (7/17) in the control group, 28.5% (2/7) in the high protease inhibitor group and 0% in the low protease inhibitor group. The increase in the plasma beta-endorphin levels in the control group was statistically significant. When E-3123 was given 30 min after the induction of pancreatitis, the increase in the plasma beta-endorphin levels in the high protease inhibitor group was also found to be increased statistically significant, compared with preinduction levels, but the increase was statistically significantly lower than that in the control group. Plasma beta-endorphin levels in the low protease inhibitor group, however, did not increase. The protease inhibitor infusion as used in this experiment can bring about improvement in hypotension and myocardial depression to an extent by inhibiting the release of betaendorphin, suggesting that the inhibitory effect of the protease inhibitor on beta-endorphin release contributes to the improvement in hemodynamic changes during pancreatitis. There may also be an optimal therapeutic dose of this drug for the treatment of hypotension and myocardial depression secondary to betaendorphin release. This work was supported in part by a grant-in-aid from the Japanese Ministry of Health and Welfare (Pancreatic Disease) and Grant 03670638 from the Japanese Ministry of Education, Science and Culture.     

牛胆酸钠诱导大鼠急性胰腺炎系列模型的研究

目的 用牛胆酸钠纯化学制剂诱导大鼠实验性急性胰腺炎系列模型。 方法 用0.25％(n=4),1.0％(n=7),2.0％(n=7)或3.5％(n=7)牛胆酸钠溶液0.1 ml/100g逆行注入Wistar大鼠胰管内诱导急性胰腺炎。诱导急性胰腺炎前,及诱导后6,12 h分别取血分离血清,测定淀粉酶值。同时,观察各实验组胰腺病理组织光镜和电镜变化。 结果 随牛胆酸钠诱导浓度提高,血清淀粉酶逐渐升高,组织病理改变依次加重。1.0％和2.0％牛胆酸钠分别诱导轻度及重度水肿型胰腺炎;3.5％牛胆酸钠则诱导坏死型胰腺炎。 结论 胰腺病变程度与牛胆酸钠诱导浓度呈正相关,本系列模型适合评价药物的防治效应。     

Proteasome inhibitor ameliorates severe acute pancreatitis and associated lung injury of rats

AIM： To observe the effect of proteasome inhibitor MG-132 on severe acute pancreatitis （SAP） and associated lung injury of rats. METHODS： Male adult SD rats were randomly divided into SAP group, sham-operation group, and MG-132 treatment group. A model of SAP was established by injection of 5% sodium taurocholate into the biliary- pancreatic duct of rats. The MG-132 group was pretreated with 10 mg/kg MG-132 intraperitoneally （ip） 30 min before the induction of pancreatitis. The changes in serum amylase, myeloperoxidase （MPO） activity of pancreatic and pulmonary tissue were measured. The TNF-α level in pancreatic cytosolic fractions was assayed with an enzyme-linked immunosorbent assay （ELISA） kit. Meanwhile, the pathological changes in both pancreatic and pulmonary tissues were also observed. RESULTS： MG-132 significantly decreased serum amylase, pancreatic weight/body ratio, pancreatic TNF-α level, pancreatic and pulmonary MPO activity （P 〈 0.05）. Histopathological examinations revealed that pancreatic and pulmonary samples from rats pretreated with MG-132 demonstrated milder edema, cellular damage, and inflammatory activity （P 〈 0.05）. CONCLUSION： The proteasome inhibitor MG-132 shows a protective effect on severe acute pancreatitis and associated lung injury of rats.     

Effect of a new cholecystokinin receptor antagonist loxiglumide on acute pancreatitis in two experimental animal models

We evaluated the effects of a new cholecystokinin (CCK) receptor antagonist, loxiglumide, in a model of mild pancreatitis induced by repeated injections of cerulein and in a severe necrotizing form of pancreatitis induced by retrograde ductal injection of sodium taurocholate (NaTc) in rats. A single subcutaneous injection or oral administration of 50 mg/kg of body weight of loxiglumide almost completely reduced the increases of serum amylase activity and pancreatic wet weight, and caused histologic improvements of the cerulein-induced acute pancreatitis when given 30 min before the first cerulein injection. Loxiglumide was also effective in reducing the elevated serum amylase activity, pancreatic wet weight, and histologic alterations even when administered after the induction of acute pancreatitis. However, loxiglumide offered no apparent beneficial effects when given 30 min before and 3 h after the induction of acute pancreatitis by NaTc as determined by changes in serum amylase activity, pancreatic wet weight, and histology. These results do not necessarily suggest that CCK is not important in the pathogenesis of pancreatitis, but do suggest that the sole blockade of peripheral CCK receptors is ineffective against NaTc-induced severe necrotizing pancreatitis.     

Combined treatment with C1 esterase inhibitor and antithrombin III improves survival in severe acute experimental pancreatitis.

BACKGROUND: Patients with severe acute pancreatitis die of complications closely related to the systemic activation of protease cascades. AIM: To examine the effects of human C1 esterase inhibitor (C1 INH) and antithrombin III (AT III) on two experimental models of acute pancreatitis. METHODS: Oedematous pancreatitis was induced by continuous intravenous infusion of caerulein and haemorrhagic pancreatitis by retrograde injection of sodium taurocholate into the biliopancreatic duct. C1 INH and AT III were given intravenously, either before or after the induction of pancreatitis. Treatment with C1 INH and AT III had no beneficial effect on oedematous pancreatitis. On the other hand, combined C1 INH and AT III therapy improved the survival in haemorrhagic pancreatitis compared with treatment with human serum albumin. This reduction in mortality was found regardless of whether the treatment was given prophylactically or therapeutically. CONCLUSIONS: Treatment with C1 INH and AT III represents a promising therapeutic concept for patients with severe haemorrhagic pancreatitis.     

血必净对大鼠重症急性胰腺炎的治疗作用

目的:探讨血必净对大鼠重症胰腺炎(severe acute pancreatitis,SAP)的治疗作用.方法:经十二指肠乳头逆行胆胰管注射3.5％牛磺胆酸钠建立SAP模型,给予血必净治疗,观察血清中淀粉酶含量、白介素-6(interleukin-6,IL-6)、丙二醛(malondialdehyde,MDA)、超氧化...     

Phospholipase A2 activity in taurocholate-induced acute pancreatitis in the rat model

The activity of phospholipase A2 (PA2) was measured in the plasma of rats after the induction of acute pancreatitis. Buffered sodium taurocholate (3.75% w/v), injected into the pancreatico-biliary duct, was used to induce acute pancreatitis. Blood was taken at 1-h intervals for the measurement of phospholipase A2, glucose, lipase, and arterial gases. Plasma lipase was markedly elevated in the test groups, indicating acute pancreatitis, but no significant difference in PA2 activity was seen between the controls and the test group. However, in four animals the PA2 activity was elevated and in all cases this was accompanied by a low arterial pO2. This supports the theoretical role of PA2 in the pathogenesis of the respiratory complications observed in severe acute pancreatitis.     

Protective effect of misoprostol, a synthetic prostaglandin E1 analog, on cerulein-induced acute pancreatitis in rats.

This study was performed to assess the effects of misoprostol, a synthetic prostaglandin E1 analog, on cerulein-induced pancreatitis. Per group of 10 each, male Wistar rats received either cerulein (2.5 micrograms/kg/h subcutaneously), cerulein and misoprostol (500 micrograms/kg intraperitoneally at 0 and 4 h), or saline. Rats were killed 6 h after the first injection. Misoprostol treatment significantly reduced interstitial edema and acinar cell lesions induced by hyperstimulation. Pancreatic amylase and chymotrypsin contents were increased by cerulein and returned towards control levels in the misoprostol-treated group. The lysosomal volume density and the pancreatic beta-D-glucuronidase activity were significantly increased after hyperstimulation. The two parameters were significantly reduced by misoprostol. A protective effect of misoprostol against lesions induced by cerulein hyperstimulation would be a consequence of a lysosomal stabilizating effect.     

大鼠ERCP术后胰腺炎模型的建立及意义

目的建立内镜逆行胰胆管造影(ERCP)术后胰腺炎大鼠模型．并与牛黄胆酸所诱发胰腺炎模型进行对照．为研究药物预防ERCP术后胰腺炎提供实验和理论依据。方法16只SD大鼠随机分为3组，实验组(6只)：以恒定压力(50mmHg)胰胆管注射30％泛影葡胺持续2min：对照组(6只)：按0．1m1／100g．0．2ml／min速度用微量推射泵在胰胆管内注入5％牛磺胆酸；假手术组(4只)：打开腹腔翻动胰腺后关腹。24h后开腹取胰腺组织作病理学检查，并检测血淀粉酶。结果24h后实验组及对照组胰腺与假手术组比较不论在大体病理，还是组织学病理的变化上均有显著差异，实验组和对照组血清淀粉酶也显著高于假手术组，而实验组和对照组差异不显著。结论恒定压力下胰胆管注射泛影葡胺建立的大鼠胰腺炎模型模拟了人ERCP术后胰腺炎过程，而且与牛黄胆酸所诱导的胰腺炎模型有类似的病理和淀粉酶变化，为研究预防ERCP术后胰腺炎的发生打下了基础。     

Effect of oral administration of AZD8309, a CXCR2 antagonist,on the severity of experimental pancreatitis

IntroductionAcute pancreatitis is a common gastrointestinal disorder burdened with a high mortality. Two pathophysiological events during experimental pancreatitis are thought to determine the clinical course: premature digestive protease activation and tissue infiltration by inflammatory cells. We have investigated the effect of AZD8309, a potent and orally bioavailable antagonist of the chemokine receptor CXCR2, which has been proposed to regulate the transmigration of neutrophils.MethodsMale C57BL6 mice (25–30 g) received gavage feeding of AZD8309 (50 mg/kg/BW) or mannitol (controls) twice daily starting 3 h prior to pancreatitis induction. Mild pancreatitis was induced by i.p. caerulein administration (50 μg/kg BW), severe pancreatitis by intraductal taurocholate (2%). Pancreas, lung, and serum was harvested up to 48 h after pancreatitis induction and used for histopathology, amylase, lipase, cathepsin B, trypsin, and elastase activity measurements, myeloperoxidase (MPO) content and cytokine concentrations.ResultsOral administration of AZD8309 significantly reduced MPO in the pancreas and lungs (8 h & 24 h) and reduced intrapancreatic trypsin and elastase activity (8 h) in caerulein-pancreatitis. In taurocholate-pancreatitis AZD8309 reduced cathepsin B activity and MPO. Serum cytokine levels were reduced by AZD8309 as well as histopathological damage.ConclusionThe CXCR2 antagonist AZD8309 reduced the transmigration of neutrophils as well as intrapancreatic protease activation in experimental pancreatitis. This effect was sufficient to reduce the overall severity of the disease. CXCR2 may therefore be a viable therapeutic target and AZD8309 a suitable agent for the treatment of acute pancreatitis.     

Prevention of the spread of experimental acute pancreatitis by intraductal administration of a synthetic protease inhibitor in dogs

The effect of a synthetic protease inhibitor, gabexate mesilate (GM), which was administered directly into the pancreatic duct, on acute pancreatitis induced by sodium taurocholate in dogs was investigated. Intraductal administration of GM significantly inhibited intrapancreatic trypsin activity at 24 h, compared with the control. The survival rate 10 days after initiation of pancreatitis for the group in which GM was administered intraductally was 100%, whereas that for the control group was 25%. Serial blood biochemical analysis and histopathological findings suggested that the progress of pancreatitis was favorably influenced by intraductal administration of GM.     

Choledochoduodenal fistula at the anterior wall of the duodenal bulb: a rare complication of duodenal ulcer

A 38 year-old man was admitted to our hospital with the chief complaint of epigastralgia. His laboratory data revealed leukocytosis and increased serum amylase, and abdominal ultrasonography revealed diffuse swelling of the pancreas. Thus, he was diagnosed as having acute pancreatitis. Moreover, abdominal computed tomography showed pneumobilia in the gallbladder and the common bile duct. Gastroduodenal fiberscopy demonstrated peptic ulcer scars around a foramen with smooth margins at the anterior wall of the duodenal bulb. The bile juice flowed from the bottom of the foramen. Endoscopic retrograde cholangiopancreatography revealed the fistula between the common bile duct and the anterior wall of the duodenal bulb, but not the posterior wall. However, there was no pancreatico-biliary maljunction and no stones in the gallbladder or bile duct. This is a rare case of choledochoduodenal fistula at the anterior wall of the duodenal bulb caused by duodenal peptic ulcer disease.     

Trypsinogen activation and glutathione content are linked to pancreatic injury in models of biliary acute pancreatitis

Summary Conclusion In models of biliary acute pancreatitis, which might resemble the situation in humans, premature activation of trypsinogen inside the pancreas (“autodigestion”) occurs and is correlated with the extent of ductal and parencymal injury. It is accompanied by a critical spending of protease inhibitors and glutathione, compromising important acinar cell defense and maintenance mechanisms. Background Premature activation of pancreatic digestive enzymes and profound changes of levels of certain biochemical compounds have been implicated in the pathophysiology of acute pancreatitis. Hitherto, little information on their role in biliary acute pancreatitis has been available. Methods Three types of injury to the pancreaticobiliary duct system of various severity were induced in rats—ligation of the common bile-pancreatic duct, retrograde infusion of electrolyte, or retrograde infusion of taurocholate solution—and were compared to sham-operated animals. Trypsin, trypsin inhibitory capacity (TIC), reduced glutathione (GSH), and other compounds were measured in pancreatic tissue. Histopathology, as well as serum amylase, lipase, and γ-glutamyl transferase (γGT) were assessed. Results Histopathology and elevated activity of γGT in the serum revealed increasing severity of pancreatic injury from sham operation through retrograde duct infusion with taurocholate. GSH was diminished even in macroscopically normal-appearing tissue, but significantly lower in altered (hemorrhagic)-looking sections. Conversely, tissue levels of trypsin were significantly increased. TIC was elevated only in the duct obstruction model, whereas it was reduced in the retrograde duct infusion models. This work is dedicated to Prof. Dr. Georg Strohmeyer (former chief of the Division of Gastroenterology at the Heinrich-Heine-University, Düsseldorf, Germany) on occasion of his 70th birthday.