Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.11.1.7 (peroxidase)
65,474 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chemoactivation of the neutrophil (PMN) via the complement system has been observed in many inflammatory conditions and is thought to play a pathogenic role in acute pancreatitis. This study examined the effects of PMN depletion in experimental hemorrhagic pancreatitis and tested the role played by complement. Severe pancreatitis was induced by a choline-deficient, 0.5% ethionine-supplemented diet in female Institute of Cancer Research (ICR) mice weighing 11-13 g. Neutropenia was induced by an antibody injection. Total complement depletion was achieved by tail vein injections of cobra venom factor (CVF). Serum amylase levels and local pancreatic injury were not significantly modulated by either PMN or complement depletion at 72 hours. Systemic and remote organ injury, assessed by the formation of ascites, hematocrit, and serum alanine aminotransferase levels, was significantly reduced in neutropenic mice but failed to be moderated by complement depletion. In addition, liver and lung myeloperoxidase activity was independent of complement depletion. At 5 days, mortality was zero in PMN-depleted mice. There was no improvement in survival in the CVF-treated group. Neutrophils are important in the systemic injury and mortality of severe pancreatitis. PMN chemoactivation involves mechanisms other than complement.
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PMID:Neutrophils, not complement, mediate the mortality of experimental hemorrhagic pancreatitis. 1113 69

We examined the effects of fasting and non-fasting on gallstone-related acute pancreatitis by the occlusion of the common bile duct (OCD). We prepared a rat OCD-induced pancreatitis model under both fasting and non-fasting conditions, and we measured amylase activity in ascites as well as production of inflammatory cytokines and chemokines. We also examined the pathology of the pancreas, myeloperoxidase (MPO) activity in some tissues and mortality rates. In the fasted OCD group, ascites containing a large amount of amylase, interleukin 1beta (IL-1beta), interleukin 6 (IL-6), and cytokine-induced neutrophil chemoattractant-1 (CINC-1) as well as marked hemorrhage and necrosis of the pancreatic acinar cells were observed. Pulmonary MPO activity increased 3.4-fold compared to the control group. In the non-fasted OCD group, there was no development of ascites. Slight necrosis of acinar cells and slight increases in pulmonary MPO activity were observed. In addition, in the fasted OCD group, the cumulative mortality rate was 50% 6 days after ligation. However, in the non-fasted OCD group, none of the animals died. These results suggest that gallstone-related severe pancreatitis depends on fasting-related structural and/or functional changes in the pancreas. Moreover, increased production of inflammatory cytokines and chemokines in ascites under fasting condition may be involved in multiple organ failure resulting from severe acute pancreatitis.
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PMID:Fasting exacerbates acute pancreatitis by occlusion of the common bile duct in rats. 1120 19

The molecular mechanisms that lead from acute pancreatitis (AP) to multiple organ failure remain to be clarified. We previously reported that ascitic fluids from a rat model of severe acute pancreatitis (pancreatitis-associated ascitic fluids, PAAF) transcriptionally activated endothelial cells and leukocytes in vitro. To clarify the role of ascitic fluids on the development of multiple organ failure in AP, we examined the effects of PAAF on the prognosis and immunohistologic findings in cerulein pancreatitis, an experimental model of mild pancreatitis in vivo. Intraperitoneal injection of PAAF decreased the survival rates in a dose-dependent manner. Histologically, destruction of vessels, alveolar septal thickening, interstitial hypertrophy, and infiltration of inflammatory cells were prominent in the lung of PAAF-injected rats. Transcription factor, nuclear factor KB (NF-kappaB) was activated and the mRNA levels of tumor necrosis factor-alpha and interleukin-1beta were increased in the lung of the PAAF-injected rats. The permeability index assessed by Evans blue assay and the lung myeloperoxidase activity levels were significantly higher in the PAAF-injected rats than in controls. Inhibition of NF-kappaB ameliorated the histologic findings and improved the survival rates. Our results suggest that PAAF play a role in the pathogenesis of lung injury in severe AP, at least in part through the activation of NF-kappaB.
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PMID:Ascites of rat experimental model of severe acute pancreatitis induces lung injury. 1134 43

Taurine, or 2-aminoethane sulfonic acid, is an intracellular amino acid and has been suggested to have a function in protecting biological systems from oxidative tissue damage. The aim of this study was to determine the effect of taurine against cerulein-induced acute pancreatitis in rats. Acute pancreatitis was induced by administering three subcutaneous injections of cerulein (40 microg/kg body weight) at 1-hour intervals, while taurine was administered intravenously at graded doses (30, 100, or 300 mg/kg, respectively) following the first cerulein injection. The severities of pancreatitis and lung injury were determined by measuring biochemical parameters, tissue myeloperoxidase (MPO), and histological changes. To clarify the mechanism of taurine, serum IL-1beta and TNF-alpha levels and tissue concentrations of malondialdehyde (MDA) were evaluated. In cerulein-induced acute edematous pancreatitis, treatment with taurine significantly decreased hyperamylasemia, tissue MPO, pancreatic edema, and the extent of pancreatic and pulmonary injury. Taurine decreased MDA concentration in the pancreas and lung, but not the serum cytokine concentration. We would conclude that taurine has beneficial effects in cerulein-induced acute pancreatitis and lung injuries by preventing the production of oxygen free radicals.
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PMID:Effects of taurine on cerulein-induced acute pancreatitis in the rat. 1140 26

Production of nitric oxide (NO) by inducible nitric oxide synthase (iNOS) has been proposed as a pathogenic factor in acute pancreatitis, but its role has still not been fully examined. The present study explored the role of iNOS in cerulein-induced acute pancreatitis using iNOS-deficient mice. Twelve- to 14-week-old male mice (C57B1/6 and iNOS-deficient) were administered cerulein by intraperitoneal (i.p.) injection at hourly intervals for 7 hours and killed 24 hours later after the first dose. Pancreatic wet weight, pancreatic myeloperoxidase (MPO) activity, and levels of plasma nitrite and serum amylase were measured. In another experiment isosorbide dinitrate (an NO donor) was given by oral gavage every 6 hours for 24 hours beginning simultaneously with cerulein injections in iNOS-deficient mice. Cerulein administration dose-dependently increased pancreatic wet weight, myeloperoxidase activity, and levels of nitrite and amylase in C57B1/6 mice. These parameters (except nitrite levels) were significantly intensified in iNOS-deficient mice. At the dose employed, cerulein failed to increase nitrite levels in iNOS-deficient mice. The susceptibility to cerulein toxicity in iNOS-deficient mice was abolished by NO donor treatment. NO release from an iNOS source appears to play a protective role in cerulein-induced pancreatitis. At least in part, NO may prevent neutrophil accumulation after cerulein administration.
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PMID:Susceptibility to cerulein-induced pancreatitis in inducible nitric oxide synthase-deficient mice. 1145 Nov 53

Oxidative stress plays an important role in the early stage of acute pancreatitis as well as the associated multiple organ injury. Here we compare the degree of pancreatitis caused by cerulein in mice lacking the inducible (or type 2) nitric oxide synthase (iNOS) and in the corresponding wild-type mice. Intraperitoneal injection of cerulein resulted in wild-type mice in a severe, acute pancreatitis, which was characterized by edema, neutrophil infiltration, tissue hemorrhage and cell necrosis as well as increases in the serum levels of amylase and/or lipase. The infiltration of the pancreatic tissue of these animals with neutrophils (measured as increase in myeloperoxidase activity) was associated with up-regulation/expression of the adhesion molecules ICAM-1 and P-selectin as well as signs of enhanced lipid peroxidation (e.g., increased tissue levels of malondialdehyde). Immunohistochemical examination demonstrated a marked increase in the staining (immunoreactivity) for nitrotyrosine and poly (ADP-ribose) synthetase (PARS) in the pancreas of cerulein-treated iNOS wild-type mice. In contrast, the degree of pancreatic inflammation and tissue injury (histological score), upregulation/expression of P-selectin and ICAM-1, the staining for nitrotyrosine and PARS, and lipid peroxidation was markedly reduced in pancreatic tissue sections obtained from cerulein-treated iNOS-deficient mice. These findings support the view that iNOS plays an important, pro-inflammatory role in the acute pancreatitis caused by cerulein in mice.
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PMID:Inducible nitric oxide synthase-deficient mice exhibit resistance to the acute pancreatitis induced by cerulein. 1202 64

Intracellular Ca(2+)-changes not only participate in important signaling pathways but have also been implicated in a number of disease states including acute pancreatitis. To investigate the underlying mechanisms in an experimental model mimicking human gallstone-induced pancreatitis, we ligated the pancreatic duct of Sprague-Dawley rats and NMRI mice for up to 6 h and studied intrapancreatic changes including the dynamics of [Ca(2+)](i) in isolated acini. In contrast to bile duct ligation, pancreatic duct obstruction induced intra-pancreatic trypsinogen activation, leukocytosis, hyperamylasemia, and pancreatic edema and increased lung myeloperoxidase activity. Although resting [Ca(2+)](i) in isolated acini rose by 45% to 205 +/- 7 nmol, the acetylcholine- and cholecystokinin (CCK)-stimulated calcium peaks as well as the amylase secretion declined, but neither the [Ca(2+)](i)-signaling pattern nor the amylase output in response to the Ca(2+)-ATPase inhibitor thapsigargin nor the secretin-stimulated amylase release were impaired by pancreatic duct ligation. On the single cell level pancreatic duct ligation reduced the percentage of cells in which submaximal secretagogue stimulation was followed by a physiological response (i.e. Ca(2+) oscillations) and increased the percentage of cells with a pathological response (i.e. peak plateau or absent Ca(2+) signal). Moreover, it reduced the frequency and amplitude of Ca(2+) oscillation as well as the capacitative Ca(2+) influx in response to secretagogue stimulation. Serum pancreatic enzyme elevation as well as trypsinogen activation was significantly reduced by pretreatment of animals with the calcium chelator BAPTA-AM. These experiments suggest that pancreatic duct obstruction rapidly changes the physiological response of the exocrine pancreas to a Ca(2+)-signaling pattern that has been associated with premature digestive enzyme activation and the onset of pancreatitis, both of which can be prevented by administration of an intracellular calcium chelator.
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PMID:Early changes in pancreatic acinar cell calcium signaling after pancreatic duct obstruction. 1252 41

Glucocorticoids are potent anti-inflammatory drugs. The molecular mechanisms underlying these effects have not yet been fully revealed. The aim of the present study was to establish whether methylprednisolone pretreatment is beneficial and if it can block the pancreatic DNA binding of the transcription factor nuclear factor-kappaB (NF-kappaB) and proinflammatory cytokine synthesis during cholecystokinin-octapeptide (CCK)-induced acute pancreatitis in rats. Additionally, we set out to investigate the potential effects of methylprednisolone and CCK on pancreatic heat shock protein (HSP) synthesis. The dose-response (5-40 mg/kg) and time-course (6-72 h) curves of methylprednisolone on pancreatic HSP60 and HSP72 synthesis were evaluated following methylprednisolone treatment. We demonstrated that methylprednisolone specifically and dose-dependently induced HSP72 in the pancreas of rats, while it did not have a significant effect on HSP60 expression. The pancreatitis was induced near the peak level of HSP72 synthesis (2 x 30 mg/kg body weight [b.w.] methylprednisolone i.m. at an interval of 12 h, followed by a 12-h recovery period after the second injection of methylprednisolone) by administering 2 x 100 microg/kg CCK subcutaneously at an interval of 1 h. The injections of CCK in the vehicle-pretreated group significantly elevated the levels of pancreatic HSP60 and HSP72 2-4 h after the second CCK injection. Methylprednisolone pretreatment ameliorated many of the examined laboratory (the pancreatic weight/body weight [p.w./b.w.] ratio, the serum amylase activity, the plasma trypsinogen activation peptide concentration, the pancreatic levels of tumor necrosis factor-alpha and interleukin-6, the degree of lipid peroxidation, protein oxidation, nonprotein sulfhydryl group content and the pancreatic myeloperoxidase activity) and morphological parameters of the disease. Methylprednisolone pretreatment did not influence pancreatic NF-kappaB DNA binding, but decreased proinflammatory cytokine synthesis in this acute pancreatitis model. The findings suggest that the anti-inflammatory effect of large doses of methylprednisolone in secretagogue-induced pancreatitis occurs downstream of NF-kappaB DNA binding, and that increased pancreatic HSP72 synthesis may play a role in the protective effect of the drug.
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PMID:The anti-inflammatory effect of methylprednisolone occurs down-stream of nuclear factor-kappaB DNA binding in acute pancreatitis. 1262 May 16

The transcription factor nuclear factor kappaB (NF-kappaB) has been shown to have a critical role in the pathogenesis of sodium taurocholate- and cerulein-induced acute pancreatitis by regulating the expression of many proinflammatory genes in the pancreas. Heat shock proteins (HSPs), on the other hand, protect the pancreas against cellular damage. The aims of the present study were: (i) to investigate pancreatic NF-kappaB activation, proinflammatory cytokine synthesis, and cytoprotective HSP induction during L-arginine- (Arg-) induced acute pancreatitis in rats, and (ii) to establish whether pretreatment with pyrrolidine dithiocarbamate (PDTC) or methylprednisolone (MP) can block the activation of pancreatic NF-kappaB and determine their effects on the severity of Arg-induced acute pancreatitis. The dose-response (3 or 4 g/kg) and time-effect (0.5-96 h) curves relating to the action of Arg on pancreatic NF-kappaB activation and IL-1beta, TNF-alpha, HSP60, and HSP72 synthesis were evaluated. Various doses of PDTC or MP were administered 1 h before the induction of pancreatitis. We demonstrated that Arg specifically and dose-dependently induces pancreatitis, activates NF-kappaB (only the 3 g/kg dose) and proinflammatory cytokine synthesis, and increases the expressions of HSP60 and HSP72 in the pancreas of rats. The lower dose of Arg induced a less severe pancreatitis, but larger increases in the levels of HSPs. The present work supports and extends earlier observations that NF-kappaB activation is a common mechanism in acute pancreatitis, although it is dose dependent and occurs at a later stage in Arg-induced pancreatitis as compared with other models. PDTC and MP pretreatment dose-dependently blocked NF-kappaB activation and proinflammatory cytokine expression and ameliorated many of the examined laboratory (the pancreatic weight/body weight ratio, the pancreatic myeloperoxidase activity, the pancreatic contents of protein, amylase and trypsinogen, the degrees of lipid peroxidation and protein oxidation, and the nonprotein sulfhydryl group content) and morphological parameters of the disease. These findings suggest that pretreatment with PDTC or MP has an anti-inflammatory effect during Arg-induced pancreatitis, which is at least partly mediated by the inhibition of NF-kappaB activation and proinflammatory cytokine synthesis. The increased levels of HSPs most probably act to limit the severity of the disease.
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PMID:NF-kappaB activation is detrimental in arginine-induced acute pancreatitis. 1263 47

Acute pancreatitis is an inflammatory process of variable severity, and leukocytes are thought to play a key role in the development of pancreatitis and pancreatitis-associated lung injury. The effects of mediators released by these inflammatory cells may induce tissue damage. The aim of our study was to evaluate the role of the chemokine, macrophage inflammatory protein-2 (MIP-2), in the pathogenesis of cerulein-induced pancreatitis and pancreatitis-associated lung injury. The severity of pancreatitis was measured by serum amylase, pancreatic edema, acinar cell necrosis, and myeloperoxidase activity. Lung injury was quantitated by evaluating lung microvascular permeability and lung myeloperoxidase activity. To determine the role of MIP-2 in the pathophysiology of the disease, anti-MIP-2 antibody was administered either 1 hour before or 2 hours after the start of cerulein administration. MIP-2 concentrations increased in serum, pancreas, and lung tissues in mice treated with cerulein. Anti-MIP-2 antibody administrated either before or after cerulein partially protected against pancreas and lung injury. These results show that MIP-2 plays a key role in the pathophysiology of acute pancreatitis and that MIP-2 blockade may improve the outcome of the disease.
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PMID:Role of macrophage inflammatory peptide-2 in cerulein-induced acute pancreatitis and pancreatitis-associated lung injury. 1269 50


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