Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030305 (pancreatitis)
 16,014 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To investigate the mechanism by which the pancreatic acinar cells are injured in animals with an obstructed common channel, we measured the amount of lysosomal enzymes and of amylase in the pancreatico-biliary juice in rats with pancreatico-biliary duct obstruction (PBDO). We tested the protective effect of a new potent synthetic protease inhibitor, E3123 (4-guanidinobenzoate methanesulfonate), on the exocrine pancreas in this model of PBDO and secretin infusion. Blockage of PBD for 4 hours and secretin (0.2 CU/kg.hr) infusion caused a significant rise in portal serum amylase and cathepsin B levels, pancreatic water content, and pancreatic amylase content, as well as redistribution of cathepsin B in acinar cells. These changes tended to continue for 12 hours after the removal of PBDO and disappeared at 24 hours. All the changes induced by PBDO with secretin infusion were no longer observed at 48 hours. The administration of 5 mg/kg.hr of E3123 during PBDO markedly attenuated all the parameters examined in this study. Thus, it had a significant protective effect on acinar cells in this model. E3123 in a dose of 2 mg/kg.hr had a partial, but significant, protective effect. These results indicate the possible usefulness of E3123 in the treatment of pancreatic duct obstructed pancreatitis.
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PMID:Effect of short-termed pancreatico-biliary duct obstruction on lysosomal enzyme in rats: protective effect of a potent new protease inhibitor, E-3123. 128 76

Circumstantial evidence suggests that gallstone-induced pancreatitis is triggered by obstruction of the pancreatic duct. In this report I will review the results of studies conducted during the last decade that have employed the diet-induced, secretagogue-induced, and duct obstruction-induced models of experimental pancreatitis to investigate the early events that lead to the development of acute pancreatitis. In each of these models, digestive enzyme zymogens and the lysosomal hydrolase cathepsin B were found to become colocalized. These observations have led to the hypothesis that intra-acinar cell activation of digestive enzyme zymogens by lysosomal hydrolases may be an important critical event in the development of acute pancreatitis. Recent morphologic studies evaluating the initial 24 hours after ligation of the opossum pancreatic duct indicate that the earliest lesions in this model of hemorrhagic pancreatitis occur in acinar cells.
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PMID:How and where does acute pancreatitis begin? 128 81

This study was designed to evaluate the effects of direct pancreatic surface cooling on the exocrine pancreas. We measured the changes in serum amylase levels, pancreatic water, amylase and cathepsin B as a lysosomal enzyme, content, histological changes of acinar cells, and the subcellular distribution of cathepsin B after 1-2- and 3-hours of direct pancreatic cooling in rats. In addition, we evaluated the in-vivo amylase and cathepsin B output stimulated by caerulein, in-vitro lysosomal and mitochondrial fragility as well as the pancreatic adenylate energy metabolism. 2-hours cooling showed slight yet significant changes, but 3-hours cooling caused most significant changes including hyperamylasemia, increased pancreatic amylase content and very mild histological changes. Furthermore, 3-hours cooling caused a remarkable redistribution of cathepsin B activity from the lysosomal fraction to the heavier zymogen fraction, and colocalization of the lysosomal enzyme with the digestive enzyme, the impaired amylase and cathepsin B output into pancreatic juice stimulated by caerulein as well as the accelerated fragility of lysosomes and mitochondria, and impaired pancreatic adenylate energy metabolism. These results indicate the impaired exocrine pancreatic functions induced by direct pancreatic cooling injury induced by cooling as shown in the other models of experimental pancreatitis. Moreover, this cooling model of pancreatitis seems to be useful in understanding the early events in the pathogenesis of acute pancreatitis, and we must take these "cold" injuries of exocrine pancreas into considerations, particularly in the pancreas transplantation and in other major abdominal surgeries where the pancreas is exposed to cooling.
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PMID:Effect of hypothermia on pancreatic acinar cells in rats. 128 73

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.
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PMID:Cytoprotective effects of prostaglandins and a new potent protease inhibitor in acute pancreatitis. 128 94

The role of infectious factors in the pathogenesis of acute pancreatitis and the protective effect of combined therapy with a new potent synthetic protease inhibitor, E3123, and a new potent synthetic cephalosporin, Shiomarin (SM) were examined in rat acute pancreatitis. Sodium taurocholate injection into the pancreatico-biliary duct of rats caused severe pancreatitis with a high mortality rate, characterized by hyperamylasemia, high amylase activity in ascitic fluid, and hyperendotoxemia and a high serum level of fibrin degradation products (FDP), redistribution of cathepsin B from the lysosomal fraction to the zymogen fraction. In rats with E3123 infusion almost all parameters were improved, including mortality rate, serum and ascitic fluid amylase levels, plasma endotoxin and serum FDP levels, and distribution of lysosomal enzyme. But combination therapy with E3123 and SM was significantly more protective than E3123 therapy alone. These results indicate that infection plays an important role in the development of severe pancreatitis and that combination therapy with a new synthetic protease inhibitor and a new potent antibiotic may be useful in the treatment of severe pancreatitis.
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PMID:Combined therapy of a cephalosporin, Shiomarin and a new potent protease inhibitor, E3123 in rat taurocholate-induced pancreatitis. 130 80

Activation of pancreatic digestive zymogens within the pancreatic acinar cell may be an early event in the development of pancreatitis. To detect such activation, an immunoblot assay has been developed that measures the relative amounts of inactive zymogens and their respective active enzyme forms. Using this assay, high doses of cholecystokinin or carbachol were found to stimulate the intracellular conversion of at least three zymogens (procarboxypeptidase A1, procarboxypeptidase B, and chymotrypsinogen 2) to their active forms. Thus, this conversion may be a generalized phenomenon of pancreatic zymogens. The conversion is detected within ten minutes of treatment and is not associated with changes in acinar cell morphology; it has been predicted that the lysosomal thiol protease, cathepsin B, may initiate this conversion. Small amounts of cathepsin B are found in the secretory pathway, and cathepsin B can activate trypsinogen in vitro; however, exposure of acini to a thiol protease inhibitor (E64) did not block this conversion. Conversion was inhibited by the serine protease inhibitor, benzamidine, and by raising the intracellular pH, using chloroquine or monensin. This limited proteolytic conversion appears to require a low pH compartment and a serine protease activity. After long periods of treatment (60 minutes), the amounts of the active enzyme forms began to decrease; this observation suggested that the active enzyme forms were being degraded. Treatment of acini with E64 reduced this late decrease in active enzyme forms, suggesting that thiol proteases, including lysosomal hydrolases, may be involved in the degradation of the active enzyme forms. These findings indicate that pathways for zymogen activation as well as degradation of active enzyme forms are present within the pancreatic acinar cell.
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PMID:Intracellular proteolysis of pancreatic zymogens. 134 58

Phase I clinical trials of the purine analog 2',3'-dideoxyinosine (ddl) revealed that 10% of the patients developed pancreatitis, yet there was no clear relationship between increasing doses of ddl and the development of pancreatitis. To test the effects of chronic ddl administration on the structure and function of the rat pancreas, male Wistar rats were given ddl at 100 mg/kg/day i.p. for 35 days or 1400 mg/kg/day for 30 days, in two divided doses. Serum amylase levels, pancreatic tissue water content (edema) and pancreatic morphology by light and electron microscopic examination of pancreata from ddl-treated rats were similar to those of rats receiving saline injections only (controls). 2',3'-Dideoxyinosine administration did not alter the subcellular distribution of the lysosomal enzyme cathepsin B, whose redistribution to a more dense zymogen granule-enriched subcellular fraction is an early indicator of acute pancreatitis. Dispersed pancreatic acini from rats receiving ddl (100 mg/kg/day for 30 days) were incubated in vitro for 15 min with either caerulein or carbamylcholine as secretory stimuli. There was no detectable difference in the stimulatable amylase secretion from ddl-treated animals compared to the control group. Based on these findings, we conclude that ddl has no direct toxic effect on the rat pancreas. 2',3'-Dideoxyinosine may be contributing to pancreatitis in acquired immunodeficiency syndrome patients by potentiating other pancreatotoxic agents or by its action on a pancreas that is already altered by the human immunodeficiency virus infection.
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PMID:In vivo and in vitro effects of the azidothymidine analog dideoxyinosine on the exocrine pancreas of the rat. 137 99

The present study investigated the protective effects of the new potent synthetic protease inhibitors, ONO3307 (4-sulfamoyl phenyl-4-guanidinobenzoate methanesulfonate) and FOY007 (gabexate misilate), on the exocrine pancreas in rat caerulein-induced acute pancreatitis in both in vitro and in vivo experiments. These protease inhibitors prevented hyperamylasemia, pancreatic edema, congestion of amylase, redistribution of lysosomal enzyme in acinar cells, and lactic dehydrogenase (LDH) discharge from dispersed acini. They also inhibited the cathepsin B leakage from the lysosomes in a dose-dependent manner in doses of 2-10 mg/kg.h of ONO3307 and 20-50 mg/kg.h of FOY007. These results indicate that both ONO3307 and FOY007 exert protective effects against pancreatitis at subcellular levels in lysosomes and cellular or organelle membranes. Proteases appear to be important in the pathogenesis and development of acute pancreatitis, and low-molecular-weight protease inhibitors may be of clinical use in the treatment of acute pancreatitis.
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PMID:Protection by a new synthetic protease inhibitor, ONO3307, of the rat exocrine pancreas during acute edematous pancreatitis induced by a supramaximal dose of caerulein in comparison with FOY007. 138 36

To investigate the possible secretion of lysosomal enzymes into pancreatic juice during stimulation with a pancreatic secretagogue under both physiological and pathological conditions, we measured the amount of cathepsin B, a lysosomal enzyme, in the pancreatic juice during the infusion of 6 different concentrations of caerulein (0.02, 0.05, 0.2, 0.5, 1.0, and 2.0 micrograms/kg. hr). In one group of rabbits the pancreatic duct was only cannulated (free-flow group); in others the pancreatic duct was obstructed for 7 hours and secretin was infused at 0.2 CU/kg. hr (obstructed group). In addition, we evaluated the effect of the intraduodenal instillation of a liquid meal (2 g/kg) on the secretion of lysosomal enzymes into pancreatic juice. Caerulein stimulated the secretion of cathepsin B into pancreatic juice in a dose-dependent manner, as it did that of amylase, and at higher concentrations of caerulein (1.0 and 2.0 micrograms/kg. hr), both cathepsin B output and amylase output were decreased. There was a significant positive correlation between cathepsin B output and amylase output into pancreatic juice during stimulation with caerulein. Blockage of the pancreatic duct for 7 hours caused a significant rise in serum amylase levels and a redistribution of cathepsin B activity in the pancreatic subcellular fractions, as a result of which an increased amount of cathepsin B was recovered in the pellet obtained by 1000 x g centrifugation for 15 min, which contained many zymogen granules. These changes noted after short-term pancreatic duct obstruction are very similar to those previously noted in the early stage of diet-and caerulein-induced experimental pancreatitis, suggesting the colocalization of lysosomal enzyme and digestive enzymes. In the duct-obstructed animals, the secretion of cathepsin B stimulated by caerulein was significantly greater than in the free-flow group. Furthermore, the intraduodenal instillation of a liquid meal caused the secretion of cathepsin B into the pancreatic juice along with amylase. These results indicate that under physiological conditions, such as food intake, lysosomal enzymes are secreted into the pancreatic juice in response to stimulation by gut hormones in the same manner as classical pancreatic digestive enzymes. Moreover, zymogen colocalized with lysosomal enzymes in duct-obstructed animals is secreted into pancreatic juice in increased amounts together with digestive enzymes; this finding suggests that lysosomal enzymes play important pathophysiological roles in pancreatic juice and that acinar cells are altered to maintain cellular organization by secreting the potentially dangerous lysosomal enzymes. This pancreatic duct-obstructed rabbit model should be useful in clarifying the early events of acute pancreatitis.
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PMID:Secretion of lysosomal and digestive enzymes into pancreatic juice under physiological and pathological conditions in rabbits. 138 3

A study was carried out to evaluate the effects of direct cooling on the exocrine pancreas. Changes in amylase and cathepsin B release, and in the subcellular distribution of amylase and cathepsin B were measured after 1, 2 and 3 h of direct pancreatic cooling in rats. Cooling for 2 and 3 h caused significant hyperamylasaemia and increased pancreatic amylase content, but minimal histological change. Furthermore, 3 h of cooling caused marked redistribution of cathepsin B activity from the lysosomal fraction to the heavier zymogen fraction, and co-localization of lysosomal and digestive enzymes; amylase and cathepsin B output into pancreatic juice after caerulein stimulation were also reduced. These results show that direct pancreatic cooling impairs exocrine function and implicate lysosomal enzymes in the pathogenesis of pancreatic injury, in agreement with results from other models of experimental pancreatitis.
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PMID:Direct surface cooling of the exocrine pancreas in the rat. 138 98


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