ceruletide and Edema

Hydrogen sulfide (H2S) and substance P play a key role in inflammation. Using animal models of inflammation of different etiologies such as acute pancreatitis, sepsis, burns, and joint inflammation, studies have recently shown an important role of the proinflammatory action of H2S and substance P. Also, H2S contributes to inflammation in different conditions via substance P. This chapter reviews methods and key data that have led to our current understanding of the role of H2S and substance P in inflammation.

Topics: Acute Disease; Animals; Burns; Carrageenan; Ceruletide; Disease Models, Animal; Drug Synergism; Edema; Endotoxemia; Hydrogen Sulfide; Lipopolysaccharides; Lung Injury; Mice; Pancreatitis; Substance P

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.

Topics: Acute Disease; Amino Acids; Amylases; Animals; Ceruletide; Cholelithiasis; Choline Deficiency; Disease Models, Animal; Edema; Enzyme Precursors; Ethionine; Hydrolases; Mice; Pancreatitis; Protein Biosynthesis; Proteins; Rabbits

Acute pancreatitis (AP) is an inflammatory disease of the exocrine pancreas. Disruptions in organelle homeostasis, including macroautophagy/autophagy dysfunction and endoplasmic reticulum (ER) stress, have been implicated in human and rodent pancreatitis. Syntaxin 17 (STX17) belongs to the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) subfamily. The Qa-SNARE STX17 is an autophagosomal SNARE protein that interacts with SNAP29 (Qbc-SNARE) and the lysosomal SNARE VAMP8 (R-SNARE) to drive autophagosome-lysosome fusion. In this study, we investigated the role of STX17 in the pathogenesis of AP in male mice or rats induced by repeated intraperitoneal injections of cerulein. We showed that cerulein hyperstimulation induced AP in mouse and rat models, which was characterized by increased serum amylase and lipase activities, pancreatic edema, necrotic cell death and the infiltration of inflammatory cells, as well as markedly decreased pancreatic STX17 expression. A similar reduction in STX17 levels was observed in primary and AR42J pancreatic acinar cells treated with CCK (100 nM) in vitro. By analyzing autophagic flux, we found that the decrease in STX17 blocked autophagosome-lysosome fusion and autophagic degradation, as well as the activation of ER stress. Pancreas-specific STX17 knockdown using adenovirus-shSTX17 further exacerbated pancreatic edema, inflammatory cell infiltration and necrotic cell death after cerulein injection. These data demonstrate a critical role of STX17 in maintaining pancreatic homeostasis and provide new evidence that autophagy serves as a protective mechanism against AP.

Topics: Acute Disease; Animals; Autophagy; Ceruletide; Disease Models, Animal; Edema; Humans; Male; Mice; Pancreatitis; Rats; SNARE Proteins

Acute pancreatitis (AP) is a potential gastrointestinal problem most commonly associated with pancreatic inflammation and acinar cells injury. Nimbolide (NB), isolated from the tree Azadirachta indica, possesses antioxidant and anti-inflammatory effects. Here, we aimed to investigate the pancreatic protective effects of NB in ameliorating cerulein-induced pancreatic inflammation and apoptosis in AP model and evaluate the potential mechanism of action. AP was induced in Swiss albino mice by six-hourly intraperitoneal exposures of cerulein (50 µg/kg/hr) and pre-treatment of NB (0.3 and 1 mg/kg) 7 days prior to the cerulein exposure. Various parameters associated with AP in plasma and pancreatic tissues were evaluated. Severity of AP was effectively ameliorated by NB as shown by reducing pancreatic edema, plasma amylase and lipase levels, MPO levels and in cerulein-induced histological damage. Further, the antioxidant effect of NB was associated with a significant inhibition of oxidative-nitrosative stress in Raw 264.7 cells and cerulein-induced AP mice. Moreover, NB suppressed proinflammatory cytokines, iNOS and nitrotyrosine expression. In addition, NB inhibited NF-κB activation and increased SIRT1 expression in cerulein challenged mice. Furthermore, NB also inhibited pancreatic apoptosis by downregulating cleaved caspase 3 and Bax while upregulating Bcl2 expression in cerulein-treated mice. Inhibition of pancreatic inflammation and apoptosis resulted in attenuation of cerulein-induced AP. These results suggest that NB exerts strong anti-pancreatitis effects against cerulein-induced AP by combating inflammatory and apoptosis signaling via SIRT1 activation.

Topics: alpha-Amylases; Animals; Apoptosis; Ceruletide; Edema; Injections, Intraperitoneal; Limonins; Male; Mice; NF-kappa B; Oxidative Stress; Pancreas; Pancreatitis; RAW 264.7 Cells; Signal Transduction; Sirtuin 1

This study is to investigate the protective effect of Acetyl-α-boswellic acid and Acetyl-β-boswellic mixture(α/β-ABA), which is the active ingredients isolated from Frankincense, on actue pancreatitis and its mechanism. Our experimental results showed that 2 μM α/β-ABA reduced production of NO, TNF-α, IL-6, IL-10 and IL-1β in RAW264.7 cells that were stimulated with lipopolysaccharide (LPS) which indicates its anti-inflammatory role. In pancreatitis model induced by caerulein, intra-gastrical administration of 100 mg/kg α/β-ABA relieved inflammatory cells infiltration significantly and attenuated the serum elevation of amylase TNF-α and IL-6 remarkably in mice. Furthermore, α/β-ABA down-regulated mitogen-activated protein kinase (MAPK) family phosphorylated proteins in pancreas, including phosphorylated p38, ERK1/2 and JNK, to reduce the serum inflammatory factors. Finally, α/β-ABA alleviated the pancreatic edema and inflammatory cell infiltration in pancreatitis mice model. This study suggests that α/β-ABA may be targeted for drug development against pancreatitis via modulating MAPKs pathway.

Topics: Animals; Cell Survival; Ceruletide; Cytokines; Disease Models, Animal; Down-Regulation; Edema; Inflammation; Lipopolysaccharides; Mice; Mice, Inbred C57BL; Mitogen-Activated Protein Kinases; Pancreatitis; RAW 264.7 Cells; Triterpenes

Severe acute pancreatitis is a highly lethal disease caused by systemic inflammatory response syndrome, leading to multiple organ failure. We recently showed that histidine-rich glycoprotein (HRG) supplemental therapy ameliorated septic acute respiratory distress syndrome due to unnecessary neutrophil activation and immunothrombosis formation. Here, we evaluated the effect of HRG on lung inflammation followed by pancreatitis in a severe acute pancreatitis mouse model.. Mice received intraperitoneal injections of cerulein 7 times (100 μg/kg each) at 1-hour intervals to induce acute pancreatitis. Immediately after the first cerulein injection, phosphate-buffered saline, human serum albumin (20 mg/kg), or HRG (20 mg/kg) was intravenously injected. One hour after the last cerulein injection, phosphate-buffered saline or lipopolysaccharide (5 mg/kg) was intravenously injected into the tail vein. We evaluated lung inflammatory level after pancreatitis.. We observed significantly decreased plasma HRG levels in an acute pancreatitis mouse model. Histidine-rich glycoprotein treatment inhibited lung edema and the accumulation of neutrophil in severe acute pancreatitis, but HRG did not directly affect pancreatitis. Moreover, HRG suppressed tumor necrosis factor α, inducible nitric oxide synthase, interleukin 6, and neutrophil elastase mRNA expression and myeloperoxidase activity in the lung.. These data suggested that HRG ameliorated lung inflammation secondary to pancreatitis.

Topics: Acute Disease; Animals; Ceruletide; Disease Models, Animal; Edema; Gene Expression; Humans; Interleukin-6; Leukocyte Elastase; Lung; Neutrophils; Nitric Oxide Synthase Type II; Pancreatitis; Proteins; Severity of Illness Index; Tumor Necrosis Factor-alpha

Bacillopeptidase is a serine peptidase, known for its fibrinolytic activity. However, a very little information is known about its in vivo inflammatory and/or anti-inflammatory properties. Thus, to understand whether bacillopeptidase incorporation can regulate pancreatitis or not, the cerulein-induced pancreatitis model was used, and the role of bacillopeptidase on pancreatitis was studied. In this study, 46 kDa protein was purified from Bacillus subtilis and identified as bacillopeptidase CFR5 (BPC) through MS/MS analysis. The nutritional prophylactic group was orally fed with two doses of BPC (100 μg/Kg/BW of rat) 6 h before cerulein administration and analyzed for its effect on intestine and pancreas inflammation, cytokines, and pancreatitis marker gene expression. BPC administration significantly reduced the severity of pancreatitis by decreasing serum amylase, lipase, pancreatic edema and myeloperoxidase activity. The pretreatment with BPC suppressed the pancreatic pro-inflammatory and inflammatory cytokines production including IL-6, IL-1β, TNF-α, IL-2, IL-4, IL-5, IL-10, and IL-13 in both pancreas and serum samples. Moreover, BPC supplementation restored pancreatitis mediated disruption of intestinal barrier integrity by upregulating tight junction proteins (ZO-1, occludin), antimicrobial peptides (DEFB1, CRAMP), MUC-2, TFF3 expression and by enhancing SCFA's production. Pretreatment with BPC suppressed the intestinal inflammation with reduced cytokines production in the colon and ileal region of cerulein-induced pancreatitis. Thus, BPC based pretreatment protocol is a novel intervention to prevent acute pancreatitis.

Topics: Administration, Oral; Animals; Anti-Inflammatory Agents, Non-Steroidal; Antimicrobial Cationic Peptides; Bacillus subtilis; Bacterial Proteins; Cathelicidins; Ceruletide; Cytokines; Defensins; Edema; Gene Expression Regulation; Male; Mucin-2; Occludin; Pancreas; Pancreatitis; Rats; Rats, Wistar; Serine Endopeptidases; Trefoil Factor-3; Zonula Occludens-1 Protein

To create acute pancreatitis condition experimentally in rats using cerulein, and to reveal histopathological effects in pancreatic tissue with erdosteine.. An experimental study.. Department of General Surgery, Duzce University, Turkey, from June to October 2014.. Thirty male Wistar albino rats were divided into three groups. No procedures were applied to Group 1. The rats in Group 2 and Group 3 were injected cerulein, to establish an experimental pancreatitis model and the blood amylase and lipase values were examined. The rats in Group 3 were given 10 mg/kg erdosteine. This treatment was continued for another 2 days and the rats were sacrificed. The pancreatic tissues were examined histopathologically for edema, inflammation, acinar necrosis, fat necrosis, and vacuolization.. The lipase and amylase values and the histopathological examination of pancreatic tissues evidenced that the experimental acute pancreatitis model was established and edema, inflammation, acinar necrosis, fat necrosis, and vacuolization were observed in the pancreatic tissues. The statistical results suggest that erdosteine can decrease the edema, inflammation, acinar necrosis, fat necrosis and vacuolization scores in the tissues.. The severity of acute pancreatitis, induced by cerulein in rats, is reduced with the use of erdosteine.

Topics: Acute Disease; Amylases; Animals; Ceruletide; Disease Models, Animal; Edema; Expectorants; Lipase; Male; Necrosis; Pancreas; Pancreatitis; Rats; Rats, Wistar; Thioglycolates; Thiophenes; Treatment Outcome

BACKGROUND We evaluated the hematological, biochemical, and histopathological effects of Montelukast on pancreatic damage in an experimental acute pancreatitis model created by cerulein in rats before and after the induction of pancreatitis. MATERIAL AND METHODS Forty rats were divided into 4 groups with 10 rats each. The study groups were: the Cerulein (C) group, the Cerulein + early Montelukast (CMe) group, the Cerulein + late Montelukast (CMl) group, and the Control group. The pH, pO2, pCO2, HCO3, leukocyte, hematocrit, pancreatic amylase, and lipase values were measured in the arterial blood samples taken immediately before rats were killed. RESULTS There were statistically significant differences between the C group and the Control group in the values of pancreatic amylase, lipase, blood leukocyte, hematocrit, pH, pO2, pCO2, HCO3, and pancreatic water content, and also in each of the values of edema, inflammation, vacuolization, necrosis, and total histopathological score (P<0.05). When the CMl group and C group were compared, no statistically significant differences were found in any parameter analyzed. When the CMe group was compared with the C group, pancreatic amylase, lipase, pH, PO2, pCO2, HCO3, pancreatic water content, histopathological edema, inflammation, and total histopathological score values were significantly different between the groups (P<0.05). Finally, when the CMe group and the Control group were compared, significant differences were found in all except 2 (leukocyte and pO2) parameters (P<0.05). CONCLUSIONS Leukotriene receptor antagonists used in the late phases of pancreatitis might not result in any benefit; however, when they are given in the early phases or prophylactically, they may decrease pancreatic damage.

Topics: Acetates; Amylases; Animals; Ceruletide; Cyclopropanes; Disease Models, Animal; Edema; Leukotriene Antagonists; Lipase; Male; Pancreatitis; Quinolines; Rats; Rats, Sprague-Dawley; Sulfides

Acute pancreatitis accounts for almost 250.000 hospital admissions annually in the United States. Most promising treatment approaches are preventive; however, little is known about the early factors initiating acute pancreatitis. We aimed to evaluate the preventive effects of enoxaparin and hesperidin in cerulein-induced acute pancreatitis.. We used 70 Wistar albino rats for this study. Rats were divided into 7 groups: control group, and groups that were administered cerulein(Group 2), enoxaparin (Group 3), hesperidin (Group 4), cerulein with enoxaparin (Group 5), cerulein with hesperidin (Group 6), and cerulein with both enoxaparin and hesperidin (Group 7). Edema formation; leukocyte infiltration; measurement of the amylase level, pancreatic tissue weight, and pancreatic tissue oxidative capacity; and chemiluminescence using luminol, lucigenin, and nitric oxide levels as indices of tissue oxidative capacity were used to evaluate pancreatitis.. Acute edematous mild pancreatitis was induced in groups 2, 5, and 6 by cerulein injections. Enoxaparin and hesperidin significantly decreased (p < 0.001) all the tested parameters in these rats. Enoxaparin and hesperidin did not offer complete protection but showed 50% decrease in edema formation. The preventive agents showed no superiority to each other. Further, when enoxaparin and hesperidin were used in combination, no significant additive effects with regard to anti-inflammatory and anti-oxidative actions were present.. We showed that both enoxaparin and hesperidin exerted significant preventive effects in all the parameters related to acute pancreatitis in our experimental rat model.

Topics: Acute Disease; Amylases; Animals; Anticoagulants; Antioxidants; Ceruletide; Edema; Enoxaparin; Hesperidin; Male; Neutrophil Infiltration; Nitric Oxide; Pancreas; Pancreatitis; Rats, Wistar; Reactive Oxygen Species

The endocannabinoid system has been shown to mediate beneficial effects on gastrointestinal inflammation via cannabinoid receptors 1 (CB(1)) and 2 (CB(2)). These receptors have also been reported to activate the MAP kinases p38 and c-Jun NH(2)-terminal kinase (JNK), which are involved in early acinar events leading to acute pancreatitis and induction of proinflammatory cytokines. Our aim was to examine the role of cannabinoid receptor activation in an experimental model of acute pancreatitis and the potential involvement of MAP kinases. Cerulein pancreatitis was induced in wild-type, CB(1)-/-, and MK2-/- mice pretreated with selective cannabinoid receptor agonists or antagonists. Severity of pancreatitis was determined by serum amylase and IL-6 levels, intracellular activation of pancreatic trypsinogen, lung myeloperoxidase activity, pancreatic edema, and histological examinations. Pancreatic lysates were investigated by Western blotting using phospho-specific antibodies against p38 and JNK. Quantitative PCR data, Western blotting experiments, and immunohistochemistry clearly show that CB(1) and CB(2) are expressed in mouse pancreatic acini. During acute pancreatitis, an upregulation especially of CB(2) on apoptotic cells occurred. The unselective CB(1)/CB(2) agonist HU210 ameliorated pancreatitis in wild-type and CB(1)-/- mice, indicating that this effect is mediated by CB(2). Furthermore, blockade of CB(2), not CB(1), with selective antagonists engraved pathology. Stimulation with a selective CB(2) agonist attenuated acute pancreatitis and an increased activation of p38 was observed in the acini. With use of MK2-/- mice, it could be demonstrated that this attenuation is dependent on MK2. Hence, using the MK2-/- mouse model we reveal a novel CB(2)-activated and MAP kinase-dependent pathway that modulates cytokine expression and reduces pancreatic injury and affiliated complications.

Topics: Amylases; Animals; Anti-Inflammatory Agents; Apoptosis; Blotting, Western; Cannabinoids; Ceruletide; Disease Models, Animal; Dronabinol; Edema; Enzyme Activation; Immunohistochemistry; Interleukin-6; Intracellular Signaling Peptides and Proteins; Lung; Mice; Mice, Inbred C57BL; Mice, Knockout; p38 Mitogen-Activated Protein Kinases; Pancreas, Exocrine; Pancreatitis; Peroxidase; Phosphorylation; Polymerase Chain Reaction; Protein Serine-Threonine Kinases; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Trypsinogen

Clinical studies indicate that cigarette smoking increases the risk for developing acute pancreatitis. The nicotine metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is a major cigarette smoke toxin. We hypothesized that NNK could sensitize to pancreatitis and examined its effects in isolated rat pancreatic acini and in vivo. In acini, 100 nM NNK caused three- and fivefold activation of trypsinogen and chymotrypsinogen, respectively, above control. Furthermore, NNK pretreatment in acini enhanced zymogen activation in a cerulein pancreatitis model. The long-term effects of NNK were examined in vivo after intraperitoneal injection of NNK (100 mg/kg body wt) three times weekly for 2 wk. NNK alone caused zymogen activation (6-fold for trypsinogen and 2-fold for chymotrypsinogen vs. control), vacuolization, pyknotic nuclei, and edema. This NNK pretreatment followed by treatment with cerulein (40 μg/kg) for 1 h to induce early pancreatitis responses enhanced trypsinogen and chymotrypsinogen activation, as well as other parameters of pancreatitis, compared with cerulein alone. Potential targets of NNK include nicotinic acetylcholine receptors and β-adrenergic receptors; mRNA for both receptor types was detected in acinar cell preparations. Studies with pharmacological inhibitors of these receptors indicate that NNK can mediate acinar cell responses through an nonneuronal α(7)-nicotinic acetylcholine receptor (α(7)-nAChR). These studies suggest that prolonged exposure to this tobacco toxin can cause pancreatitis and sensitize to disease. Therapies targeting NNK-mediated pathways may prove useful in treatment of smoking-related pancreatitis.

Topics: alpha7 Nicotinic Acetylcholine Receptor; Animals; Atropine; Carcinogens; Cells, Cultured; Ceruletide; Edema; Enzyme Precursors; L-Lactate Dehydrogenase; Male; Mecamylamine; Nicotiana; Nitrosamines; Pancreas; Pancreatitis; Rats; Rats, Sprague-Dawley; Receptors, Adrenergic, beta; Receptors, Nicotinic; Sincalide

Pancreatitis represents a life-threatening inflammatory condition where leucocytes, cytokines and vascular endothelium contribute to the development of the inflammatory disease. The glucocorticoid-induced tumour necrosis factor (TNF) receptor family-related protein (GITR) is a costimulatory molecule for T lymphocytes, modulates innate and adaptive immune system and has been found to participate in a variety of immune responses and inflammatory processes. Our purpose was to verify whether inhibition of GITR triggering results in a better outcome in experimental pancreatitis.. In male GITR knock-out (GITR(-/-)) and GITR(+/+) mice on Sv129 background, acute pancreatitis was induced after i.p. administration of cerulein. Other experimental groups of GITR(+/+) mice were also treated with different doses of Fc-GITR fusion protein (up to 6.25 µg·mouse⁻¹), given by implanted mini-osmotic pump. Clinical score and pro-inflammatory parameters were evaluated.. A less acute pancreatitis was found in GITR(-/-) mice than in GITR(+/+) mice, with marked differences in oedema, neutrophil infiltration, pancreatic dysfunction and injury. Co-treatment of GITR(+/+) mice with cerulein and Fc-GITR fusion protein (6.25 µg·mouse⁻¹) decreased the inflammatory response and tissue injury, compared with treatment with cerulein alone. Inhibition of GITR triggering was found to modulate activation of nuclear factor κB as well as the production of TNF-α, interleukin-1β, inducible nitric oxide synthase, nitrotyrosine, poly-ADP-ribose, intercellular adhesion molecule-1 and P-selectin.. The GITR-GITR ligand system is crucial to the development of acute pancreatitis in mice. Our results also suggest that the Fc-GITR fusion protein could be useful in the treatment of acute pancreatitis.

Topics: Animals; Apoptosis; Ceruletide; Edema; Glucocorticoid-Induced TNFR-Related Protein; I-kappa B Proteins; Intercellular Adhesion Molecule-1; Interleukin-1beta; Ligands; Male; Mice; Mice, 129 Strain; Mice, Knockout; Neutrophil Infiltration; NF-KappaB Inhibitor alpha; Nitric Oxide Synthase Type II; P-Selectin; Pancreatitis; Poly(ADP-ribose) Polymerases; Receptors, Nerve Growth Factor; Receptors, Tumor Necrosis Factor; Recombinant Fusion Proteins; T-Lymphocytes; Transcription Factor RelA; Tumor Necrosis Factor-alpha

Both galanin and substance P have been separately implicated in the pathogenesis of acute pancreatitis. We compared the efficacy of the combination of the galanin antagonist galantide and the neurokinin-1 receptor antagonist L703,606 with that of either alone in the treatment of acute pancreatitis. Acute pancreatitis was induced in mice with 7-hourly caerulein injections. Galantide was co-administered with each caerulein injection commencing with the first injection (prophylactic) or 2h after the first injection (therapeutic). L703,606 was administered either 30 min before (prophylactic), or 2h after the first caerulein injection (therapeutic). Combination of the two agents was also administered. Control groups received galantide, L703,606, or saline, without caerulein. Pancreata were harvested for histological examination and estimation of myeloperoxidase activity. Plasma amylase activity was measured. Prophylactic and therapeutic administration of galantide reduced the hyperamylasemia by 37% and 30% respectively whereas only prophylactic L703,606 reduced hyperamylasemia (by 34%). Prophylactic administration of the combined antagonists reduced the hyperamylasemia by 44%. In contrast, therapeutic administration of the combination significantly increased plasma amylase levels by 27%. The plasma amylase activity in the control groups was similar to basal levels. Prophylactic and therapeutic administration of either antagonist or the combination significantly reduced myeloperoxidase activity. Galantide and L703,606 individually, and in combination, significantly reduced the acute pancreatitis-induced necrosis score. The administration of the combined antagonists does not offer any further benefit as compared to galantide alone. An interaction between neurokinin-1 and galanin receptors may occur to modulate amylase secretion.

Topics: Amylases; Animals; Anti-Inflammatory Agents, Non-Steroidal; Ceruletide; Edema; Galanin; Mice; Neurokinin-1 Receptor Antagonists; Pancreas; Pancreas, Exocrine; Pancreatitis; Peroxidase; Quinuclidines; Receptors, Galanin; Receptors, Neurokinin-1; Substance P

Cannabinoids (CBs) evoke their effects by activating the cannabinoid receptor subtypes CB1-r and CB2-r and exert anti-inflammatory effects altering chemokine and cytokine expression. Various cytokines and chemokines are produced and released by rodent pancreatic acini in acute pancreatitis. Although CB1-r and CB2-r expressed in rat exocrine pancreatic acinar cells do not modulate digestive enzyme release, whether they modulate inflammatory mediators remains unclear. We investigated the CB-r system role on exocrine pancreas in unstimulated conditions and during acute pancreatitis.. We evaluated in vitro and in vivo changes induced by WIN55,212 on the inflammatory variables amylasemia, pancreatic edema and morphology, and on acinar release and content of the cytokine interleukin-6 (IL-6) and chemokine monocyte chemo-attractant protein-1 (MCP-1) in untreated rats and rats with caerulein (CK)-induced pancreatitis.. In the in vitro experiments, WIN55,212 (10(-6) mol L(-1)) inhibited IL-6 and MCP-1 release from acinar cells of unstimulated rats and after CK-induced pancreatitis. In vivo, when rats were pretreated with WIN55,212 (2 mg kg(-1), intraperitoneally) before experimentally-induced pancreatitis, serum amylase, pancreatic edema and IL-6 and MCP-1 acinar content diminished and pancreatic morphology improved. Conversely, when rats with experimentally-induced pancreatitis were post-treated with WIN55,212, pancreatitis worsened.. These findings provide new evidence showing that the pancreatic CB1-r/CB2-r system modulates pro-inflammatory factor levels in rat exocrine pancreatic acinar cells. The dual, time-dependent WIN55,212-induced changes in the development and course of acute pancreatitis support the idea that the role of the endogenous CB receptor system differs according to the local inflammatory status.

Topics: Amylases; Animals; Benzoxazines; Body Water; Cannabinoids; Ceruletide; Chemokine CCL2; Edema; Enzyme-Linked Immunosorbent Assay; Gastrointestinal Agents; Interleukin-6; Male; Morpholines; Naphthalenes; Pancreas; Pancreatitis; Quinolines; Rats

Platelet-activating factor (PAF) is an important mediator of inflammation and postulated to be involved in the pathogenesis of acute pancreatitis. In this study, we evaluated the therapeutic effect of PAF antagonist WEB 2086 in acute experimental pancreatitis of graded severity in rats.. According to a block design, 64 animals were randomly allocated to 8 groups. Severe necrotizing pancreatitis was induced by intraductal infusion of taurocholic acid (4%, 0.4 mL), and the combination of glycodeoxycholic acid (10 mmol/L, 1.0 mL/kg, intraductal infusion) and cerulein (5 microg/kg per hour, intravenous) was applied to induce intermediate pancreatitis, or cerulein alone (5 microg/kg per hour, intravenous) to establish edematous pancreatitis. WEB 2086 was given 15 minutes after beginning the induction of pancreatitis. Pancreatic microcirculation was analyzed in vivo with an epiluminescent microscope. Histopathology was evaluated by a validated score. Trypsinogen-activating peptide and serum amylase were analyzed sequentially.. WEB 2086 had no significant influence on the breakdown of microcirculation, leukocyte adherence, histopathological damage, and amylase levels in severe necrotizing pancreatitis, intermediate pancreatitis, and edematous pancreatitis. Only in intermediate pancreatitis was there a significant reduction of trypsinogen-activating peptide levels.. In our study, PAF antagonist WEB 2086 had no beneficial effect on microcirculation in acute experimental pancreatitis.

Topics: Amylases; Animals; Azepines; Capillaries; Cell Adhesion; Ceruletide; Disease Models, Animal; Edema; Female; Glycodeoxycholic Acid; Leukocytes; Microcirculation; Oligopeptides; Pancreas; Pancreatitis; Pancreatitis, Acute Necrotizing; Platelet Activating Factor; Platelet Aggregation Inhibitors; Rats; Rats, Wistar; Regional Blood Flow; Severity of Illness Index; Taurocholic Acid; Time Factors; Triazoles

Inflammatory cytokines and oxidative stress have a central role in the pathogenesis of acute pancreatitis. Propolis is a resinous hive product collected by honeybees from various plant sources and has anti-inflammatory and anti-oxidant effects. The present work aimed to investigate the therapeutic role of ethanolic extract of propolis on a cerulein-induced acute pancreatitis model in rats.. Seventy male Wistar albino rats were used in the study. Acute edematous pancreatitis was induced by subcutaneous cerulein injection (20 microg/kg) four times at one-hour intervals. Ethanolic extract of propolis 300 mg/kg was given subcutaneously at the beginning of the procedure (ethanolic extract of propolis-1 group) or 12 h after the last cerulein injection (ethanolic extract of propolis-2 group). Serum amylase and lipase levels, white blood cell count and serum tumor necrosis factor-alpha levels were measured and pancreatic tissue was evaluated histologically.. In the acute pancreatitis group, serum amylase and lipase levels were found to be elevated and the histopathological evaluation of the tissue revealed massive edema and inflammation with less fatty necrosis when compared to the sham and control groups. Serum amylase and lipase levels and edema formation were significantly decreased in the ethanolic extract of propolis-treated groups (p<0.001). In the ethanolic extract of propolis-2 group, in particular, tissue edema was improved markedly (p=0.001). Tissue inflammation and fatty necrosis were decreased with ethanolic extract of propolis treatment; however, the improvement was not statistically significant.. Treatment with ethanolic extract of propolis improved the biochemical and histopathological findings in a rat model of experimental pancreatitis. Although our findings suggest that ethanolic extract of propolis might be considered an effective agent for the treatment of acute pancreatitis, this notion should be supported with further experimental and clinical investigations.

Topics: Acute Disease; Amylases; Animals; Anti-Infective Agents; Ceruletide; Disease Models, Animal; Edema; Gastrointestinal Agents; Lipase; Male; Pancreas; Pancreatitis; Propolis; Rats; Rats, Wistar; Treatment Outcome

To evaluate the therapeutic role of caffeic acid phenethyl ester (CAPE) in a rat model of cerulean-induced acute pancreatitis (AP).. Seventy male Wistar albino rats were divided into seven groups. Acute edematous pancreatitis was induced by subcutaneous cerulein injection (20 microg/kg) four times at 1-h intervals. CAPE (30 mg/kg) was given by subcutaneous injection at the beginning (CAPE 1 group) and 12 h after the last cerulein injection (CAPE 2 group). Serum amylase, lipase, white blood cell count, and tumor necrosis factor (TNF)-alpha levels were measured, and pancreatic histopathology was assessed.. In the AP group, amylase and lipase levels were found to be elevated and the histopathological evaluation showed massive edema and inflammation of the pancreas, with less fatty necrosis when compared with sham and control groups. Amylase and lipase levels and edema formation decreased significantly in the CAPE therapy groups (P < 0001); especially in the CAPE 2 group, edema was improved nearly completely (P = 0001). Inflammation and fatty necrosis were partially recovered by CAPE treatment. The pathological results and amylase level in the placebo groups were similar to those in the AP group. White blood cell count and TNF-alpha concentration was nearly the same in the CAPE and placebo groups.. CAPE may be useful agent in treatment of AP but more experimental and clinical studies are needed to support our observation of beneficial effects of CAPE before clinical usage of this agent.

Topics: Acute Disease; Amylases; Animals; Caffeic Acids; Ceruletide; Cytotoxins; Disease Models, Animal; Edema; Leukocyte Count; Lipase; Male; Pancreas; Pancreatitis; Phenylethyl Alcohol; Rats; Rats, Wistar; Treatment Outcome; Tumor Necrosis Factor-alpha

Glutathione depletion is a key factor in the development of acute pancreatitis. Our aim was to study the regulation of glutamate cysteine ligase, the rate-limiting enzyme in glutathione synthesis, in edematous or necrotizing pancreatitis in rats. Glutathione levels were kept low in necrotizing pancreatitis for several hours, with no increase in protein or mRNA levels of glutamate cysteine ligase subunits, despite binding of RNA polymerase II to their promoters and coding regions. The survival signal pathway mediated by ERK and c-MYC was activated, and c-MYC was recruited to the promoters. The failure in gene up-regulation seems to be due to a marked increase in cytosolic ribonuclease activity. In contrast, in edematous pancreatitis glutathione levels were depleted and rapidly restored, and protein and mRNA expression of glutamate cysteine ligase increased markedly due to enhanced transcription mediated by recruitment of c-MYC, NF-kappaB, and SP-1 to the promoters. No increase in cytosolic ribonuclease activity was found in this case. We propose a novel pathophysiological mechanism to differentiate necrotizing from edematous pancreatitis, which is the inefficient up-regulation of glutamate cysteine ligase caused by increased cytosolic ribonuclease activity in the severe form of the disease. This mechanism would abrogate a rapid recovery of glutathione levels.

Topics: Animals; Ceruletide; Edema; Gene Expression Regulation, Enzymologic; Glutamate-Cysteine Ligase; Glutathione; Male; Pancreatitis; Pancreatitis, Acute Necrotizing; Rats; Rats, Wistar; Ribonucleases; RNA Polymerase II; RNA Stability; RNA, Messenger; Taurocholic Acid; Transcription Factors; Up-Regulation

Transforming growth factors betas (TGF-betas) are implicated in pancreatic tissue repair but their role in acute pancreatitis is not known. To determine whether endogenous TGF-betas modulate the course of caerulein induced acute pancreatitis, caerulein was administered to wild-type (FVB-/-) and transgenic mice that are heterozygous (FVB+/-) for expression of a dominant negative type II TGF-beta receptor.. After 7 hourly supramaximal injections of caerulein, the pancreas was evaluated histologically and serum was assayed for amylase and lipase levels. Next, the effects of caerulein on amylase secretion were determined in mouse pancreatic acini, and cholecystokinin (CCK) receptor expression was assessed.. The normal mouse pancreas was devoid of inflammatory cells whereas the pancreas from transgenic mice contained lymphocytic infiltrates. Caerulein injection in wild-type mice resulted in 6- and 36-fold increases in serum amylase and lipase levels, respectively, increased serum trypsinogen activation peptide (TAP) levels, gross oedema and a marked inflammatory response in the pancreas that consisted mainly of neutrophils and macrophages. By contrast, FVB+/- mice exhibited minimal alterations in response to caerulein with attenuated neutrophil-macrophage infiltrates. Moreover, acini from FVB+/- mice did not exhibit restricted stimulation at high caerulein concentrations, even though CCK receptor mRNA levels were not decreased.. Our findings indicate that a functional TGF-beta signalling pathway may be required for caerulein to induce acute pancreatitis and for the CCK receptor to induce acinar cell damage at high ligand concentrations. Our results also support the concept that restricted stimulation at high caerulein concentrations contributes to the ability of caerulein to induce acute pancreatitis.

Topics: Acute Disease; Amylases; Animals; Blotting, Northern; Ceruletide; Edema; Ligands; Lipase; Mice; Mice, Transgenic; Oligopeptides; Pancreatic Diseases; Pancreatitis; Receptors, Cholecystokinin; Severity of Illness Index; Signal Transduction; Transforming Growth Factor beta

To test the hypothesis that disruption of acinar cell membranes is the earliest event that takes place after the onset of acute pancreatitis.. Cerulein and taurocholate pancreatitis were induced in rats. Furthermore, stimulation with different doses of bombesin, pilocarpine, and cerulein was performed. Five to 180 minutes after initiation of treatment, animals were killed. Disruption of cell membranes was detected by the penetration of the experimental animal's own albumin or immunoglobulin G (IgG) into acinar cells by immunocytological localization. Tissue was further analyzed by electron microscopy and electron microscopic immunostaining.. Animals with pancreatitis displayed significantly greater antialbumin and anti-IgG immunostaining in the cytoplasm of acinar cells and in vacuoles in comparison with controls, confirming membrane disruption. This was not detectable after stimulation with bombesin, pilocarpine, and nonsupramaximal doses of cerulein. The first changes were seen after 5 minutes of induction of pancreatitis. Results were verified by electron microscopy and electron microscopic immunohistochemistry.. The penetration of albumin and IgG into acinar cells indicates that wounding of their plasma membrane occurs at the onset of acute pancreatitis. Disruption of the membranes could be expected to allow the influx of calcium ions, causing massive intracellular alterations, and exit of molecules, such as enzymes from acinar cells.

Topics: Acute Disease; Animals; Capillary Permeability; Cell Membrane; Ceruletide; Cytoplasm; Disease Models, Animal; Edema; Immunoglobulin G; Male; Microscopy, Electron, Transmission; Microscopy, Immunoelectron; Pancreas, Exocrine; Pancreatitis; Rats; Rats, Sprague-Dawley; Serum Albumin; Taurocholic Acid; Time Factors; Vacuoles

To observe the therapeutic effect of early administration of exogenous Basic fibroblast growth factor (bFGF) on acute edematous pancreatitis (AEP) in rats.. Thirty male Sprague-Dawley rats were randomly divided into three (n = 10): normal control group (group I), AEP group (group II) and AEP with bFGF treatment group (group III). AEP was induced by subcutaneous injection of cerulein (5.5 microg/kg and 7.5 microg/kg) at 1 h interval into rats of groups II and III. Three hours after induction of AEP, 100 microg/kg bFGF was administrated intraperitoneally for 1 h to group III rats. For test of DNA synthesis in acinar cells, 5-bromo-2'-deoxyuridine (BrdU) labeling solution was intraperitoneally injected into the rats of groups II and III 24 h after bFGF treatment. The changes in serum amylase, lipase, pancreatic tissue wet/dry ratio were detected.. In bFGF treatment group, there was a significant decrease in the volume of serum amylase, lipase and the pancreatic wet/dry weight ratio(1383.0+/-94.6 U/L, 194.0+/-43.6 U/L, 4.32+/-0.32) compared to AEP group (3464+/-223.7 U/L, 456+/-68.7 U/L, 6.89+/-0.47) (P < 0.01), and no significant difference was found between bFGF treatment and control group (1289+/-94.0 U/L, 171+/-23.4 U/L, 4.12+/-0.26, P > 0.05). The inflammatory changes such as interstitial edema, polymorphonuclear neutrophils (PMNs) and vacuolization were significantly ameliorated compared to AEP group (P < 0.01). A small number of BrdU-labeled nuclei were observed in acinar cells of AEP rats (1.8+/-0.3 nuclei/microscopic field, n = 10) while diffuse BrdU-labeled nuclei were found in bFGF-treated rats (18.9+/-1.4 nuclei/microscopic field, n = 10) (P < 0.01). Immunohistochemical study showed increased DNA synthesis in pancreatic acinar cells.. Early administration of exogenous bFGF has significant therapeutic effect on cerulein-induced acute edematous pancreatitis in rats. Its mechanism is related to the amelioration of inflammation and facilitation of pancreatic regeneration.

Topics: Amylases; Animals; Ceruletide; Disease Progression; DNA; Edema; Fibroblast Growth Factor 2; Immunohistochemistry; Lipase; Male; Organ Size; Pancreas; Pancreatitis, Acute Necrotizing; Rats; Rats, Sprague-Dawley; Regeneration

The recruitment of inflammatory cells contributes significantly to tissue injury in acute pancreatitis. This process implies several molecular interactions between circulating and endothelial cells. The adhesion molecule junctional adhesion molecule C (JAM-C) is involved in leukocyte transendothelial migration and it can form homophilic (JAM-C/JAM-C) and heterophilic interactions with the leukocyte integrin alpha(M)beta(2). In this study, the effect of early administration of monoclonal antibodies directed against JAM-C in cerulein-induced acute pancreatitis was assessed. This reagent significantly blocked influx of leukocytes, release of serum amylase, secretion of inflammatory cytokines, and acinar cell necrosis. These effects were rapid and protected against tissue injury throughout the duration of the model. Conversely, cerulein-induced acute pancreatitis was more severe in transgenic mice overexpressing JAM-C on endothelial cells under the control of the Tie2 promoter. It is proposed that JAM-C expressed by endothelial cells contributes to the pathophysiology of acute pancreatitis and could be considered a target for clinical applications.

Topics: Acute Disease; Amylases; Animals; Antibodies, Monoclonal; Blotting, Western; Cell Adhesion Molecules; Ceruletide; Chemotaxis, Leukocyte; Edema; Endothelial Cells; Immunoglobulins; Immunohistochemistry; Interleukin-6; Membrane Proteins; Mice; Mice, Inbred C57BL; Mice, Transgenic; Models, Animal; Necrosis; Pancreas; Pancreatitis

In acute pancreatitis, local as well as systemic organ complications are mediated by the activation of various inflammatory cascades. The role of complement in this setting is unclear. The aim of the present study was to determine the level of complement activation in experimental pancreatitis, to evaluate the interaction of complement and leukocyte-endothelium activation, and to assess the effects of complement inhibition by soluble complement receptor 1 (sCR1) in this setting. Necrotizing pancreatitis was induced in Wistar rats by the combination of intravenous cerulein and retrograde infusion of glycodeoxycholic acid into the biliopancreatic duct; edematous pancreatitis was induced by intravenous cerulein only. In control animals, a sham operation (midline laparotomy) was performed. Complement activation, leukocyte sequestration, and pancreatic as well as pulmonary injury were assessed in the presence/absence of sCR1. Increased levels of C3a were found in necrotizing but not in edematous pancreatitis. When complement activation in necrotizing pancreatitis was blocked by sCR1, levels of C3a and total hemolytic activity (CH50) were decreased. Leukocyte-endothelial interaction, as assessed by intravital microscopy, and pancreatic as well as pulmonary organ injury (wet-to-dry weight ratio, MPO activity, and histology) were ameliorated by sCR1. As a result of the present study, necrotizing but not edematous pancreatitis is characterized by significant and early complement activation. Based on the interaction of complement and leukocytes, complement inhibition by sCR1 may be a valuable option in the treatment of leukocyte-associated organ injury in severe pancreatitis.

Topics: Animals; Ceruletide; Complement Activation; Complement C1s; Complement C3a; Complement System Proteins; Edema; Glycodeoxycholic Acid; Leukocytes; Lung; Lung Diseases; Male; Pancreas; Pancreatitis, Acute Necrotizing; Peroxidase; Rats; Rats, Wistar; Recombinant Proteins

Central neuropeptides play a role in many physiological functions through the autonomic nervous system. We have recently demonstrated that central injection of a thyrotropin-releasing hormone (TRH) analog increases pancreatic blood flow through vagal and nitric oxide-dependent pathways. In this study, the central effect of a TRH analog on experimental acute pancreatitis was investigated in rats. Acute pancreatitis was induced by two intraperitoneal injections of cerulein (40 microg/kg) at 1-h interval. Either stable TRH analog, RX 77368 (5-100 ng), or saline was injected intracisternally 15 min before the first cerulein injection under ether anesthesia. Serum amylase level was measured before and 5 h after the first cerulein injection. Pancreatic wet/dry weight ratio and histological changes were also evaluated. Intracisternal TRH analog inhibited cerulean-induced elevation of serum amylase level, increase in pancreatic wet/dry weight ratio and pancreatic histological changes, such as interstitial edema, inflammation and vacuolization. The pancreatic cytoprotection induced by central TRH analog was abolished by subdiaphragmatic vagotomy and N(G)-nitro-L-arginine-methyl ester (L-NAME), but not by 6-hydroxydopamine (6-OHDA). Intravenous administration of the TRH analog did not influence cerulein-induced acute pancreatitis. These results indicate that the TRH analog acts in the central nervous system to protect against acute pancreatitis through vagal and nitric oxide-dependent pathways.

Topics: Adrenergic Agents; Amylases; Animals; Central Nervous System; Ceruletide; Dose-Response Relationship, Drug; Edema; Enzyme Inhibitors; Male; Neuropeptides; NG-Nitroarginine Methyl Ester; Nitric Oxide; Oxidopamine; Pancreas; Pancreatitis; Peptides; Pyrrolidonecarboxylic Acid; Rats; Rats, Wistar; Thyrotropin-Releasing Hormone; Time Factors

To investigate the changes of platelet endothelial cell adhesion molecule-1 (PECAM-1) expression on polymorphonuclear leukocytes (PMNs) in peripheral circulation and pancreatic microcirculation in cerulein-induced acute edematous pancreatitis (AEP).. Fifty Wistar rats were randomly divided into control group (n = 10) and AEP group (n = 40). A model of AEP was established by subcutaneous injection of cerulein 5.5 and 7.5 mug/kg at 0 and 1 h after the beginning of experiment respectively. PECAM-1 expression on PMNs from splenic vein and inferior vena cava was determined by RT-PCR at mRNA level and determined by flow cytometry at protein level.. In experimental rats, an increased PECAM-1 mRNA expression was seen from 4 to 8 h of AEP in peripheral circulation (0.77+/-0.25%, 0.76+/-0.28%, 0.89+/-0.30%, 1.00+/-0.21%), while in pancreatic microcirculation, expression decreased from 2 h and reached the lowest level at 6 h of AEP (0.78+/-0.29%, 0.75+/-0.26%, 0.62+/-0.28%, 0.66+/-0.20%). There were significant differences at 8-h time point of AEP between peripheral circulation and pancreatic microcirculation (1.00+/-0.21% vs 0.66+/-0.20%, P<0.05). Meanwhile, the difference at protein level was also found.. A reverse expression of PECAM-1 on PMNs was found between peripheral circulation and pancreatic microcirculation, suggesting that inhibition of PECAM-1 expression may improve the pathological change of AEP.

Topics: Acute Disease; Amylases; Animals; Ceruletide; Edema; Flow Cytometry; Gene Expression; Male; Microcirculation; Neutrophils; Organ Size; Pancreas; Pancreatitis; Platelet Endothelial Cell Adhesion Molecule-1; Rats; Rats, Wistar; Reverse Transcriptase Polymerase Chain Reaction

To determine whether ischemic preconditioning (IP) affects the development of edematous cerulein-induced pancreatitis and to assess the role of cyclooxygenase-1 (COX-1), COX-2, and heat shock protein 70 (HSP 70) in this process.. In male Wistar rats, IP was performed by clamping of celiac artery (twice for 5 min at 5-min intervals). Thirty minutes after IP or sham operation, acute pancreatitis was induced by cerulein. Activity of COX-1 or COX-2 was inhibited by resveratrol or rofecoxib, respectively (10 mg/kg).. IP significantly reduced pancreatic damage in cerulein-induced pancreatitis as demonstrated by the improvement of pancreas histology, reduction in serum lipase and poly-C ribonuclease activity, and serum concentration of pro-inflammatory interleukin (IL)-1beta. Also, IP attenuated the pancreatitis-evoked fall in pancreatic blood flow and pancreatic DNA synthesis. Serum level of anti-inflammatory IL-10 was not affected by IP. Cerulein-induced pancreatitis and IP increased the content of HSP 70 in the pancreas. Maximal increase in HSP 70 was observed when IP was combined with cerulein-induced pancreatitis. Inhibition of COXs, especially COX-2, reduced the protective effect of IP in edematous pancreatitis.. Our results indicate that IP reduces pancreatic damage in cerulein-induced pancreatitis and this effect, at least in part, depends on the activity of COXs and pancreatic production of HSP 70.

Topics: Animals; Ceruletide; Cyclooxygenase Inhibitors; Edema; HSP70 Heat-Shock Proteins; Interleukin-1; Interleukin-10; Ischemic Preconditioning; Lactones; Male; Pancreatitis; Prostaglandin-Endoperoxide Synthases; Rats; Rats, Wistar; Resveratrol; Stilbenes; Sulfones

Limited experimental models of the oedematous and necrotic types of acute pancreatitis provide some understanding of the pathophysiology of this disease. Wistar rats were treated with cerulein at 10 mg/kg of body weight or with L-arginine at 1.5 or 3 g/kg of body weight in order to induce the oedematous or necrotic type of acute pancreatitis. After the induction period we examined samples of pancreata with light and electron microscopes. Morphological examination showed profound changes in the histology of the pancreas and its acinar cells and subcellular structures, especially in the group of rats which received a higher dose of L-arginine, amounting to 3 g/kg body weight. These included parenchymal haemorrhage and widespread acinar cell necrotic changes. 4-OH-TEMPO successfully prevented morphological deterioration as well as amylase release, suggesting that the severity of the two types of disease strongly depends on the intensity of the oxidative stress. Our results lend support to the assumption that reactive oxygen species play an axial role in the pathogenesis of both types of acute pancreatitis.

Topics: Amylases; Animals; Arginine; Cell Shape; Ceruletide; Edema; Male; Oxidative Stress; Pancreas; Pancreatitis, Acute Necrotizing; Random Allocation; Rats; Rats, Wistar; Reactive Oxygen Species

Tumor necrosis factor alpha (TNF-alpha) has a central role in the pathogenesis of acute pancreatitis and related systemic complications. The aim of this study is to investigate the therapeutic effectiveness of monoclonal TNF antibody (infliximab) in acute edematous and severe necrotizing pancreatitis models in rats.. One hundred rats were randomly divided into 10 groups. Acute edematous pancreatitis (AEP) was induced by injection of cerulein 20 microg/kg 4 times subcutaneously at hourly intervals. Severe necrotizing pancreatitis (SNP) was induced by retrograde injection of 3% taurocholate into the common biliopancreatic duct. Infliximab 8 mg/kg was given via intravenous infusion. Serum amylase activity, pancreatic histopathology, myeloperoxidase enzyme activity (MPO), and pulmonary changes were assessed.. Infliximab treatment significantly decreased serum amylase activity (11939 +/- 1914 U/L versus 3458 +/- 915 U/L, P < 0.001) and histopathologic score (4.1 +/- 0.5 versus 1.5 +/- 0.3, P < 0.001) in AEP. It also suppressed neutrophil infiltration and MPO activity of the pancreatic tissue. In SNP, infliximab treatment was found to decrease pathologic score (9.4 +/- 1.2 versus 3.6 +/- 0.8, P < 0.001) and serum amylase activity (20442 +/- 2375 versus 8990 +/- 1730, P < 0.01). It ameliorated both parenchymal and fatty tissue necrosis of the pancreas. Infliximab also alleviated alveolar edema and acute respiratory distress syndrome like pulmonary complications, but the difference was not significant.. Chimeric TNF antibody, infliximab, should be evaluated for treatment of acute pancreatitis.

Topics: Acute Disease; Amylases; Animals; Antibodies, Monoclonal; Ceruletide; Edema; Infliximab; Male; Necrosis; Pancreas; Pancreatitis; Pancreatitis, Acute Necrotizing; Peroxidase; Pulmonary Edema; Rats; Rats, Wistar; Severity of Illness Index; Taurocholic Acid; Treatment Outcome; Tumor Necrosis Factor-alpha

Supramaximal dosage of the cholecystokinin analog caerulein leads to edematous pancreatitis with subsequent acinar cell destruction predominantly by apoptosis. We have used immunohistochemistry to reveal the expression of the anti-apoptotic protein galectin-3 in pancreatic acinar cells. Galectin-3, which occurs only in duct cells under physiological conditions, is expressed in a subset of acinar cells after the end of a 12-h caerulein infusion, giving rise to a "patchy" staining pattern. During the subsequent period of inflammation and regeneration, galectin-3 expression increases in those acinar cells that undergo apoptosis. By 48 h after the end of caerulein infusion, morphologically normal cells do not contain galectin-3 and participate in regeneration by proliferation. Tubular complexes, being transient structures from degenerative acini, accumulate galectin-3 in the remnants of the epithelium cells. Stimulation with supramaximal dosages of caerulein of the cell line AR4-2J, which is derived from rat pancreatic acinar cells, also results in a marked increase of galectin-3, confirming the in vivo results. We postulate that the high expression of the anti-apoptotic protein galectin-3 regulates the time course of the apoptotic process in pancreatic acinar cells.

Topics: Acute Disease; Amino Acid Sequence; Animals; Apoptosis; Cell Line, Tumor; Ceruletide; Disease Models, Animal; Edema; Fluorescent Antibody Technique, Indirect; Galectin 3; Humans; Male; Molecular Sequence Data; Pancreas; Pancreatic Ducts; Pancreatitis; Rats; Rats, Wistar; Regeneration

Extracellular regulated kinases (ERK1/2) and c-Jun N-terminal Kinases (JNK), are generally considered to play a key role in signal transduction pathways activated by a wide range of stimuli. We studied the effects of SP600125, a novel inhibitor of both JNK and ERK1/2, in male C57/BL6 mice given with an hyper-stimulating dose of cerulein (50 microg/kg for each of four injections at hourly intervals) to elicit secretagogue-induced pancreatitis. A control group received four intra-peritoneal injections of 0.9% saline at hourly intervals. Animals were randomized to receive either SP600125 (15 mg/kg i.p. administered 2 h before and 30 min after the first injection of cerulein) or its vehicle (1 ml/kg of a 10% DMSO/NaCl solution). A group of animals was killed 30 minutes after the last cerulein injection to evaluate pancreatic JNK and ERK1/2 activation by Western Blot analysis. Another group was sacrificed 2 hours after the last cerulein injection to evaluate serum lipase and amylase levels, pancreas oedema, pancreatic content of Tumor Necrosis Factor-alpha (TNF-alpha) and Intercellular adhesion molecule-1 (ICAM-1) and the histological alterations. SP600125 inhibited almost totally JNK activation (90%) and partially ERK1/2 activation (45%), reduced the serum lipase and amylase levels and the degree of oedema, blunted the increased pancreatic content of TNF-alpha and ICAM-1 and protected against the histological damage. Our data confirm that both JNK and ERK1/2 activation plays a key role in acute pancreatitis and that SP600125 may represent a potential therapeutic approach to the treatment of patients at high risk of developing this life-threatening condition.

Topics: Amylases; Analysis of Variance; Animals; Anthracenes; Blotting, Western; Ceruletide; Disease Models, Animal; Edema; Enzyme Activation; Histological Techniques; Intercellular Adhesion Molecule-1; JNK Mitogen-Activated Protein Kinases; Lipase; Male; MAP Kinase Kinase 4; Mice; Mice, Inbred C57BL; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinase Kinases; Oligonucleotides; Pancreas; Pancreatitis; Peroxidase; Reverse Transcriptase Polymerase Chain Reaction; RNA; Signal Transduction; Tumor Necrosis Factor-alpha

The investigation of the effects of the celecoxib as a cylooxygenase-2 (COX-2) inhibitor on the course of the acute necrotising pancreatitis (ANP) in rats. ANP was induced in 72 rats by standardized intraductal glycodeoxycholic acid infusion and intravenous cerulein infusion. The rats were divided into four groups (six rats in each group): Sham + saline, sham + celecoxib, ANP + saline, ANP + celecoxib. Six hours later after the ANP induction, celecoxib (10 mg/kg) or saline was given i.p. In the 12th hour, routine cardiorespiratuar, renal parameters were monitored to assess the organ function. The serum amylase, alanine amino transferase (ALT), interleukin 6 (IL-6), lactate dehydrogenase (LDH) in bronchoalveolar lavage (BAL) fluid, the serum concentration of the urea, the tissue activity of myeloperoxidase (MPO) and malondialdehyde (MDA) in pancreas and lungs were measured. The pancreas histology was examined. In the second part of the study, 48 rats were studied in four groups similar to the first part. Survival of all the rats after the induction of ANP was observed for 24 h. The induction of the pancreatitis increased the mortality from 0/12, in the sham groups to 4/12 (30%) in the acute pancreatitis with saline group, 5/12 (42%) in the acute pancreatitis with celecoxib group respectively, heart rate, the serum activities of amylase, ALT, the tissue activities of MPO, MDA in the pancreas and lung, and LDH in BAL fluid, the serum concentration of the urea and IL-6, the degree of the pancreatic damage and decreased the blood pressure, the urine production, pO(2) and the serum concentration of calcium. The use of celecoxib did not alter these changes except the serum IL-6 concentration, urine production and MPO, MDA activities in the tissue of the lungs and pancreas. Serum urea concentration and pancreatic damage in ANP + celecoxib group were insignificantly lesser than ANP + saline group. Whereas treatment with celecoxib improves lung and renal functions, the degree of pancreatic damage partially and the serum IL-6 level completely, it does not improve the cardiovascular and liver functions, the mortality rate and the calcium level. Celecoxib may be useful for the support of some organ functions during ANP in rats.

Topics: Animals; Celecoxib; Ceruletide; Cyclooxygenase Inhibitors; Disease Models, Animal; Edema; Glycodeoxycholic Acid; Inflammation; Interleukin-6; Lung; Male; Malondialdehyde; Multiple Organ Failure; Pancreas; Pancreatitis, Acute Necrotizing; Peroxidase; Pyrazoles; Rats; Rats, Sprague-Dawley; Sulfonamides; Survival Analysis; Urea; Urine

Acute pancreatitis is an inflammatory disease characterized by pancreatic tissue edema, acinar cell necrosis, hemorrhage and inflammation of the damaged gland. It is believed that acinar cell injury is initiated by the activation of digestive zymogens inside the acinar cells, leading finally to the autodigestion of the pancreas. Previous study in our laboratory demonstrated that cerulein-induced acute pancreatitis was associated with an up-regulation of local renin-angiotensin system (RAS) in rat pancreas. Therefore, the utilization of RAS inhibitors may provide a novel and alternative treatment for acute pancreatitis. By means of a rat model of cerulein-induced acute pancreatitis, results from the present study showed that an intravenous injection of saralasin, an antagonist for angiotensin II receptors, at a dose of 40 microg/kg 30 min before the induction of acute pancreatitis significantly attenuated pancreatic edema. Results from the biochemical measurements showed that pretreatment with saralasin at a dose of 20 microg/kg markedly reduced pancreatic injury, as evidenced by the decreased activities of alpha-amylase and lipase in plasma. However, the same recipe of ramiprilat, a specific inhibitor for angiotensin-converting enzyme, at a dose of 20 microg/kg did not provide any protective effect against acute pancreatitis. On the contrary, pretreatment with ramiprilat at a dose 40 microg/kg enhanced cerulein-induced pancreatic injury. Results from histopathological analysis of these RAS inhibitors further confirmed with those results as obtained from biochemical analysis. These data indicate that administration of saralasin but not ramiprilat could be protective against acute pancreatitis and that activation of pancreatic RAS in acute pancreatitis may play a role in pancreatic tissue injury.

Topics: Acute Disease; alpha-Amylases; Angiotensin Receptor Antagonists; Animals; Ceruletide; Disease Models, Animal; Edema; Injections, Intravenous; Lipase; Necrosis; Pancreatitis; Ramipril; Rats; Rats, Sprague-Dawley; Renin-Angiotensin System; Saralasin

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.

Topics: Acute Disease; Amylases; Animals; Ceruletide; Chemokine CXCL2; Disease Models, Animal; Edema; Fluorescent Antibody Technique, Indirect; Gastrointestinal Agents; Injections, Intraperitoneal; Lung Diseases; Male; Mice; Mice, Inbred Strains; Monokines; Necrosis; Pancreas; Pancreatitis; Peroxidase

1 Kinin B(2) receptor antagonists or tissue kallikrein (t-KK) inhibitors prevent oedema formation and associated sequelae in caerulein-induced pancreatitis in the rat. We have now further investigated the mechanism of kinin generation in the pancreas. 2 Kinins were elevated in the pancreatic tissue already before oedema formation became manifest. Peak values (421+/-59 pmol g(-1) dry wt) were reached at 45 min and remained elevated for at least 2 h; a second increase was observed at 24 h. Pretreatment with the B(2) receptor antagonist icatibant abolished kinin formation, while post-treatment was ineffective. 3 Total kininogen levels were very low in the pancreas of controls, but increased 75-fold during acute pancreatitis. This increase was absent in rats that were pretreated with icatibant. 4 During pancreatitis, t-KK-like and plasma kallikrein (p-KK)-like activity in the pancreas, as well as trypsinogen activation peptide (TAP) increased significantly. Icatibant pretreatment further augmented t-KK about 100-fold, while p-KK was significantly attenuated; TAP levels remained unaffected. 5 Endogenous protease inhibitors (alpha(1)-antitrypsin, alpha(2)-macroglobulin) were low in normal tissues, but increased 45- and four-fold, respectively, during pancreatitis. This increase was abolished when oedema formation was prevented by icatibant. 6 In summary, oedema formation is initiated by t-KK; the ensuing plasma protein extravasation supplies further kininogen and active p-KK to the tissue. Concomitantly, endogenous protease inhibitors in the oedema fluid inhibit up to 99% of active t-KK. Our data thus suggest a complex interaction between kinin action and kinin generation involving positive and negative feedback actions of the inflammatory oedema.

Topics: Acute Disease; alpha 1-Antitrypsin; alpha-Macroglobulins; Animals; Anti-Inflammatory Agents, Non-Steroidal; Bradykinin; Ceruletide; Edema; Enzyme Activation; Female; Kininogens; Kinins; Pancreas; Pancreatitis; Plasma Kallikrein; Rats; Rats, Sprague-Dawley; Receptors, Cell Surface; Serine Proteinase Inhibitors; Tissue Kallikreins; Trypsinogen

The role of nitric oxide (NO) in bacterial translocation (BT) associated with acute pancreatitis is controversial. We investigated the effects of the NO synthase substrate, L-arginine, and the NO synthase inhibitor, N-nitro-L-arginine methyl ester (L-NAME), on BT in caerulein-induced acute pancreatitis in rats.. Acute pancreatitis was induced by subcutaneous injections of caerulein (12 microg/kg) at 6-hour intervals for 2 days. Subcutaneous injections of L-arginine (100 mg/kg) or L-NAME (10 mg/kg) were administeredonce daily for 2 days. At 48 h, pancreatic injury and BT to the mesenteric lymph nodes (MLN), liver, and peritoneum were assessed.. Compared with controls, rats that received caerulein injections alone had increased BT to the MLN and pancreatic inflammatory changes. L-Arginine significantly reduced the inflammation and BT caused by caerulein. L-NAME did not significantly alter pancreatic inflammation. Although caerulein + L-NAME-treated rats had increased BT to the peritoneum, MLN, and liver compared with controls, rates of BT did not significantly differ between caerulein alone- and caerulein + L-NAME-treated rats.. In acute edematous pancreatitis, BT is increased and is regulated by NO. NO substrates limit BT and pancreatic inflammation associated with acute pancreatitis, probably by their bactericidal actions and ability to improve pancreatic blood flow.

Topics: Acute Disease; Animals; Arginine; Bacterial Translocation; Ceruletide; Edema; Injections, Subcutaneous; Liver; Lymph Nodes; Male; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitric Oxide Synthase; Pancreas; Pancreatitis; Peritoneum; Rats; Rats, Wistar

The nuclear factor-kappaB (NF-kappaB) is a transcription factor that plays a pivotal role in the induction of genes involved in the response to injury and inflammation. Dithiocarbamates are antioxidants that are potent inhibitors of NF-kappaB. This study tested the hypothesis that pyrrolidine dithiocarbamate (PDTC) attenuates experimental acute pancreatitis. Intraperitoneal injection of cerulein in mice resulted in severe, acute pancreatitis characterized by edema, neutrophil infiltration, tissue hemorrhage and necrosis, and elevated serum levels of amylase and lipase. Infiltration of pancreatic and lung tissue with neutrophils (measured as increase in myeloperoxidase activity) was associated with enhanced lipid peroxidation (increased tissue levels of malondialdehyde). Immunohistochemical examination demonstrated a marked increase in immunoreactivity for nitrotyrosine and intracellular adhesion molecule-1 in the pancreas and lung of cerulein-treated mice. In contrast, the degree of 1) pancreas and lung injury, 2) upregulation/expression of intracellular adhesion molecule-1, 3) staining for nitrotyrosine, and 4) lipid peroxidation was markedly reduced by pretreatment with PDTC. This study demonstrates that prevention of the activation of NF-kappaB by PDTC ameliorates the tissue injury associated with experimental murine acute pancreatitis and provides an important insight into the molecular biology of acute pancreatitis.

Topics: Amylases; Animals; Antioxidants; Blotting, Western; Ceruletide; Edema; I-kappa B Proteins; Immunohistochemistry; Inflammation; Intercellular Adhesion Molecule-1; Lipase; Lipid Peroxidation; Male; Mice; Necrosis; Neutrophils; NF-kappa B; NF-KappaB Inhibitor alpha; Pancreatitis; Peroxidase; Pyrrolidines; Rats; Thiocarbamates; Tyrosine; Up-Regulation

To study the feature of pancreatic microcirculatory impairment, especially the initial changes, in caerulein-induced experimental acute pancreatitis (AP).. The pancreatic microcirculation of caerulein-induced AP model was studied by intravital fluorescence microscopy with FITC-labeled erythrocytes (FITC-RBC), scanning electron microscopy of vascular corrosion casts, and light microscopy of Chinese ink-injected/cleared tissues.. Animals in caerulein-treated group showed hyperamylemia (X2), pancreatic oedema, infiltration of inflammatory cells in pancreas. Constrictions of intralobular arteriolar sphincters, presence of vacuoles in all layers of sphincter, and gross irregularity in capillary network of acini were found in the AP specimens. The decrease of pancreatic capillary blood flow (0.34+/-0.10 nl x min(-1) vs 0.91+/-0.06 nl x min(-1) of control, P<0.001), reduction of functional capillary density(277+/-13 cm(-1) vs 349+/-8 cm(-1) of control, P<0.001), and irregular intermittent perfusion were observed in caerulein-induced groups.. Impairment and constriction of pancreatic intralobular arteriolar sphincter are the initial microcirculatory lesions in the early phase of acute pancreatitis, and play a key role in the pancreatic ischaemia and pancreatic microvascular failure in acute pancreatitis.

Topics: Acute Disease; Amylases; Animals; Arterioles; Ceruletide; Disease Models, Animal; Edema; Erythrocytes; Fluorescein-5-isothiocyanate; Fluorescent Dyes; Male; Microscopy, Electron, Scanning; Microscopy, Fluorescence; Pancreas; Pancreatitis; Rats; Rats, Wistar; Vacuoles

Adenosine plays important roles in a variety of pathophysiologic conditions through receptor-mediated mechanisms. Recent studies have shown that adenosine exerts potent anti-inflammatory properties that are chiefly brought about through the occupancy of the A2a receptor.. To examine the effect of A2a receptor stimulation or inhibition on the pathologic findings during acute pancreatitis.. Rats were randomized into three groups and received a selective A2a receptor agonist CGS-21680 (CGS), a selective A2a antagonist 3,7-dimethyl-1-[2-propynyl]-xanthine (DMPX), or saline. Thirty minutes after the injection, acute pancreatitis was produced in the rats by seven intraperitoneal injections of caerulein. The severity of acute pancreatitis was evaluated by serum amylase activity, pancreas myeloperoxidase (MPO) activity, Evans blue extravasation, and pathologic changes of the pancreas. In addition, we investigated the effects of CGS on the pathologic findings of caerulein pancreatitis induced in neutrophil-depleted rats.. Administration of caerulein produced hyperamylasemia and morphologic changes of the pancreas including interstitial edema, acinar cell vacuolization, and infiltration of inflammatory cells. In CGS-treated rats, the pancreatic edema and the Evans blue extravasation were aggravated significantly compared with those of saline-treated rats, whereas leukocyte infiltration and MPO activity of the pancreas were decreased. In contrast to CGS, administration of DMPX ameliorated the pancreatic edema and Evans blue extravasation. Treatment with CGS accelerated the pancreatic edema in pancreatitis even after the depletion of neutrophils.. The activation of adenosine A2a receptors modulates the pathology of acute pancreatitis through at least two diverse properties. One is an anti-inflammatory effect involving neutrophils, and the other is a propagating effect for pancreatic edema formation. The actions of the A2a receptor pathways are unique, and they may have an important role in the progression of acute pancreatitis.

Topics: Adenosine; Amylases; Animals; Ceruletide; Edema; Leukocytes; Male; Pancreatitis; Phenethylamines; Purinergic P1 Receptor Agonists; Purinergic P1 Receptor Antagonists; Rats; Rats, Wistar; Receptors, Purinergic P1; Theobromine

We studied the effect of iron chelators, 2,2'-dipyridyl and desferrioxamine, on cerulein-induced pancreatitis in rats. Acute pancreatitis was induced by a single subcutaneous injection of 100 micrograms/kg body weight of cerulein, which caused hyperamylasemia and edematous pancreatitis with neutrophilic infiltration. Blood samples were collected for determination of serum amylase values and the pancreas was removed for the histological examination 6 h after the cerulein injection. Intraperitoneal administration of a ferrous iron chelator, 2,2'-dipyridyl, prior to the cerulein injection resulted in amelioration of hyperamylasemia and histological abnormalities such as edema and inflammation but not of acinar cell vacuolization. In contrast, administration of a ferric iron chelator, desferrioxamine, did not show any beneficial effects. These results indicate that administration of 2,2'-dipyridyl ameliorates the pancreatitis induced by the supramaximal dose of cerulein.

Topics: 2,2'-Dipyridyl; Acute Disease; Animals; Ceruletide; Deferoxamine; Edema; Injections, Intraperitoneal; Iron Chelating Agents; Male; Neutrophil Infiltration; Pancreatitis; Rats; Rats, Wistar

The early events in pancreatic fibrosis are poorly understood. We examined the production of collagen and matrix metalloproteinases as well as the activation of pancreatic stellate cells in a rodent model of pancreatic fibrosis.. Pancreatitis was induced in rats by hyperstimulation with cerulein (50 microg/kg/day ip) and concurrent pancreatic duct obstruction (SHOP model) for 96 h (n = 48). Sham animals were injected with saline and underwent laparotomy and manipulation of the pancreas with no duct obstruction (n = 28). Rats were sacrificed daily for 18 days. Serial pancreatic sections were stained with H&E [histology], trichrome [collagen], and alpha smooth muscle actin (alpha-SMA) antibodies [activated stellate cells]. Total pancreatic matrix metalloproteinase (MMP)-2 and 9 were determined by gelatin zymography. MMP-1 production was examined using Western blotting.. There were occasional alpha-SMA-positive cells in the pancreatic parenchyma of normal and sham animals. Within 48 h of pancreatitis induction in SHOP animals, histologic evidence of pancreatic inflammation was present, and stellate cells (alpha-SMA-positive cells) appeared surrounding pancreatic acini. The appearance of these cells was followed by collagen deposition in the same area. MMP-1 and 2 proteins increased significantly during pancreatitis while MMP-9 did not. The pancreatic architecture returned to normal by 18 days after the induction of pancreatitis.. Acute pancreatic inflammation results in stellate cell activation and collagen deposition in the same area. Collagen is then resorbed at a time when MMP-1 and 2 peak. The fibrosis of acute pancreatic inflammation in this model completely resolves with restoration of normal architecture.

Topics: Actins; Animals; Blotting, Western; Ceruletide; Collagen; Constriction; Edema; Fibrosis; Male; Matrix Metalloproteinase 1; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Metalloendopeptidases; Muscle, Smooth; Pancreas; Pancreatic Ducts; Pancreatitis; Rats; Rats, Sprague-Dawley; Tissue Distribution

Endothelin-1 has been shown to reduce pancreatic blood flow and cause focal acinar cell necrosis similar to those seen in acute pancreatitis (AP), whereas therapy with endothelin receptor antagonists enhanced pancreatic capillary blood flow (PCBF) and decreased mortality rates. The current study evaluated the role of endothelin in the development of severe AP. Trypsinogen activation peptides, acinar cell necrosis, and PCBF were used as local indicators of disease severity, fluid sequestration, cardiorespiratory and renal parameters, and colonic capillary blood flow as systemic disease indicators. The following groups of animals were examined: 1) rats with mild edematous AP and 2) severe necrotizing AP treated with and without endothelin, 3) transgenic rats overexpressing endothelin with severe AP, and 4) rats with severe AP prophylactically treated with endothelin receptor antagonists. The following observations were made: endothelin superimposed on mild AP caused hemoconcentration, a decrease in PCBF, and necrosis and ascites not seen in this model without endothelin exposure. Endothelin superimposed on severe AP had no significant effects. After induction of severe AP, less PCBF and more acinar cell necrosis were observed in transgenic rats than in their normal littermates. Prophylactic endothelin receptor antagonists improved local (acinar necrosis, PCBF) and systemic parameters (ascites, urine production, colonic capillary blood flow) of disease severity in animals with severe AP. These observations underscore the role of endothelin as a mediator of disease severity in AP and suggest that endothelin receptor blockade may become a promising therapeutic tool in this disease.

Topics: Acute Disease; Animals; Animals, Genetically Modified; Blood Pressure; Capillaries; Ceruletide; Edema; Endothelin-1; Gene Expression; Hematocrit; Male; Pancreas; Pancreatitis; Pancreatitis, Acute Necrotizing; Rats; Rats, Sprague-Dawley

Acute severe (necrotizing) pancreatitis is often associated with pancreatic or peripancreatic infection. Decreased bacterial clearance due to impaired immune defense may cause local infection. We investigated expressions of surface opsonin receptors (CD11b, complement receptor 3; CD32/CD16, immunoglobulin G Fc receptor) on local and circulatory neutrophils, in murine acute pancreatitis. The mild and severe forms of acute pancreatitis were induced by seven and 13 subcutaneous injections of caerulein, respectively. Peritoneal exudative and circulatory neutrophils were counted and assayed for receptor expressions by flow cytometry, serially at 1-72 hours after pancreatitis induction. Histologically, mild and severe forms showed edematous and necrotizing pancreatitis, respectively. The peritoneal exudative neutrophil count was greater in mild than in severe pancreatitis. Expressions of CD11b and CD32/CD16 on local neutrophils were upregulated early in mild pancreatitis. This upregulation was attenuated in severe pancreatitis. The circulatory neutrophil count was elevated in severe pancreatitis but was unchanged in mild pancreatitis. Opsonin receptor expression on circulatory neutrophils showed a transient, modest upregulation in the early phase of mild pancreatitis. Receptor-positive circulatory neutrophils showed a marked elevation that persisted throughout the course of severe pancreatitis. In conclusion, severe (necrotizing) pancreatitis is associated with reduced opsonin receptor expression on local neutrophils and enhanced expression on circulatory neutrophils, as compared with mild (edematous) pancreatitis. These changes may contribute to local infectious complications and multiple organ failure, in severe pancreatitis.

Topics: Acute Disease; Animals; Ascitic Fluid; Ceruletide; Complement Activation; Disease Progression; Drug Administration Schedule; Edema; Female; Leukocyte Count; Macrophage-1 Antigen; Mice; Mice, Inbred BALB C; Neutrophils; Pancreatitis; Pancreatitis, Acute Necrotizing; Phagocytosis; Receptors, Fc; Receptors, IgG; Receptors, Immunologic

We previously reported that serum hepatocyte growth factor (HGF) levels are elevated in patients with acute pancreatitis and that pancreatitis-associated ascitic fluid (PAAF) contains cytotoxic factor(s) inducing apoptosis on Madin-Darby canine kidney (MDCK) cells. In this study, plasma HGF levels and HGF tissue distribution were investigated in rats with experimental acute pancreatitis, and the effects of HGF on the cytotoxic activity and apoptosis-inducing activity of PAAF also were examined. Plasma HGF levels were elevated in rats with two experimental pancreatitis models of different grades of severity. The degree of its elevation was correlated with the severity and the organ dysfunctions. In rats with severe pancreatitis, HGF protein and messenger RNA (mRNA) levels significantly increased in liver, kidney, and lung, which were injured organs. When anti-HGF neutralizing antibody was administered in severe pancreatitis, liver dysfunction worsened, and apoptotic cells increased in kidney. Recombinant HGF inhibited the cytocidal activity of PAAF on MDCK cells in a dose-dependent manner. Moreover, recombinant HGF prevented the apoptotic cell death (DNA fragmentation, nuclear fragmentation, and caspase-3 activation) induced by PAAF. These results suggest that HGF is produced in injured organs and may function as an organotrophic and antiapoptotic factor against the organ injuries in acute pancreatitis.

Topics: Acute Disease; Animals; Apoptosis; Caspase 3; Caspases; Cell Line; Ceruletide; Deoxycholic Acid; DNA Fragmentation; Dogs; Edema; Hepatocyte Growth Factor; Kidney; Liver; Lung; Male; Multiple Organ Failure; Pancreatitis; Pancreatitis, Acute Necrotizing; Rats; Rats, Wistar; Recombinant Fusion Proteins; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Spleen

Pancreatic caerulein-induced activation of c-Jun NH(2)-terminal kinase (JNK) has been reported, and JNK has been proposed as a mediator during induction of hyperstimulated pancreatitis. CEP-1347 has recently been described as a specific JNK inhibitor. We tested whether CEP-1347 inhibits caerulein-induced pancreatic JNK activation in isolated acini and in vivo. CEP-1347 dose dependently inhibited acinar caerulein-induced JNK activation with nearly complete inhibition at 2 microM but had no effect on digestive enzyme release. For in vivo studies, rats were pretreated with CEP-1347 before caerulein hyperstimulation. For assessment of JNK activation and histological alterations, animals were killed 30 min or 2 and 4 h after caerulein hyperstimulation, respectively. Pancreatic wet weight, serum enzyme levels, and pancreatic activity of p38 and extracellular signal-regulated kinase (ERK) were also determined. Caerulein hyperstimulation strongly activated JNK, p38, and ERK. CEP-1347 pretreatment dose dependently reduced caerulein-induced pancreatic JNK activation without p38 or ERK inhibition. JNK inhibition also reduced pancreatic edema formation and reduced histological severity of pancreatitis. Thus we show that CEP-1347 inhibits JNK activation in vivo and ameliorates caerulein-induced pancreatitis.

Topics: Amylases; Animals; Carbazoles; Ceruletide; Dose-Response Relationship, Drug; Edema; Enzyme Activation; Enzyme Inhibitors; In Vitro Techniques; Indoles; JNK Mitogen-Activated Protein Kinases; Male; Mitogen-Activated Protein Kinases; Pancreas; Pancreatic Diseases; Pancreatitis; Rats; Rats, Sprague-Dawley

Reactive oxygen radicals, nitric oxide, and cytokines have been implicated in the initiation of pancreatic tissue damage and impairment of the pancreatic microcirculation in acute pancreatitis. Pentoxifylline is a methylxanthine derivative with rheologic and marked anti-inflammatory properties and inhibits the production of proinflammatory cytokines. We have examined whether pentoxifylline ameliorates interstitial edema, inflammatory infiltrate, and glutathione depletion associated with cerulein-induced pancreatitis. Cotreatment of animals with pentoxifylline significantly reduced cerulein-induced pancreatic inflammation and edema and attenuated the depletion of pancreatic glutathione and the increase in serum lipase activity, nitrate, and tumor necrosis factor-alpha levels. Pentoxifylline also prevented both mitochondrial swelling and damage to mitochondrial cristae caused by cerulein. Our findings provide an experimental basis for using pentoxifylline to attenuate inflammatory responses within the pancreas in acute pancreatitis and as an adjuvant in the treatment of acute pancreatitis.

Topics: Animals; Antioxidants; Ceruletide; Dose-Response Relationship, Drug; Edema; Gastrointestinal Agents; Glutathione; Lipase; Male; Microscopy, Electron; Nitric Oxide; Oxidation-Reduction; Pancreas; Pancreatitis; Pentoxifylline; Phosphodiesterase Inhibitors; Rats; Rats, Wistar; Tumor Necrosis Factor-alpha

Pancreatic oedema occurs early in the development of acute pancreatitis, and the overall extent of fluid loss correlates with disease severity. The tachykinin substance P (SP) is released from sensory nerves, binds to the neurokinin-1 receptor (NK1-R) on endothelial cells and induces plasma extravasation, oedema, and neutrophil infiltration, a process termed neurogenic inflammation. We sought to determine the importance of neurogenic mechanisms in acute pancreatitis. Pancreatic plasma extravasation was measured using the intravascular tracers Evans blue and Monastral blue after administration of specific NK1-R agonists/antagonists in rats and NK1-R(+/+)/(-/-) mice. The effects of NK1-R genetic deletion/antagonism on pancreatic plasma extravasation, amylase, myeloperoxidase (MPO), and histology in cerulein-induced pancreatitis were characterized. In rats, both SP and the NK1-R selective agonist [Sar(9) Met(O(2))(11)]SP stimulated pancreatic plasma extravasation, and this response was blocked by the NK1-R antagonist CP 96,345. Selective agonists of the NK-2 or NK-3 receptors had no effect. In rats, cerulein stimulated pancreatic plasma extravasation and serum amylase. These responses were blocked by the NK1-R antagonist CP 96,345. In wildtype mice, SP induced plasma extravasation while SP had no effect in NK1-R knockout mice. In NK1-R knockout mice, the effects of cerulein on pancreatic plasma extravasation and hyperamylasemia were reduced by 60%, and pancreatic MPO by 75%, as compared to wildtype animals. Neurogenic mechanisms of inflammation are important in the development of inflammatory oedema in acute interstitial pancreatitis.

Topics: Acute Disease; Amylases; Animals; Blood Pressure; Ceruletide; Edema; Gastrointestinal Agents; Inflammation; Male; Mice; Neurokinin-1 Receptor Antagonists; Pancreatitis; Peroxidase; Rats; Rats, Sprague-Dawley; Receptors, Neurokinin-1; Substance P

Basic fibroblast growth factor (bFGF) is one of the mitogens that facilitate endothelial proliferation and angiogenesis. This study was designed to examine the therapeutic effect of bFGF on experimental pancreatitis in rat. Edematous pancreatitis was induced by intraperitoneal injections of cerulein (50 microg/kg) at hourly intervals. BFGF (70 nmol/kg) was administered intraperitoneally after induction of pancreatitis. DNA synthesis of isolated pancreatic acinar cells of normal rats was determined as the uptake of 5-bromo-2'-deoxyuridine (BrdU) into the cells. Immunohistochemical staining of DNA synthesis in acinar cells during cerulein-induced pancreatitis was also examined with BrdU labeling in vivo technique. Cerulein administration increased serum amylase, lipase level, and wet weight of pancreatic tissue. Treatment with bFGF markedly ameliorated all these parameters. In primary culture system of isolated pancreatic acinar cells of normal rats, bFGF caused a dose-dependent increase in BrdU incorporation into DNA, showing an EC50 value of 0.8 nmol/L and a maximum response of 2.5-fold increase at a concentration of 400 nmol/L. bFGF treatment (70 nmol/kg) markedly increased BrdU labeling in the nucleus of acinar cells of the pancreatitis rats group in immunohistochemical examination when compared with control without bFGF treatment. Treatment with bFGF may represent a promising therapeutic concept for patients with acute pancreatitis.

Topics: Animals; Bromodeoxyuridine; Cell Division; Ceruletide; DNA; Edema; Fibroblast Growth Factor 2; Immunohistochemistry; Male; Pancreatitis; Rats; Rats, Wistar

The connective tissue component hyaluronan is accumulated locally in the damaged tissue during various inflammatory conditions. Owing to the strong water-binding capacity of this glycosaminoglycan, increased tissue content of hyaluronan is paralleled by the development of interstitial edema. The aim with the current experiment was to investigate whether hyaluronan is accumulated in acute pancreatitis and if increased levels of hyaluronan can be correlated to the inflammation of the pancreatic tissue.. Acute pancreatitis was induced in Sprague-Dawley rats by the administration of supramaximal doses of the cholecystokinin analogue caerulein. The animals were followed for 5 hours (n = 4), 24 hours (n = 6), or 48 hours (n = 5), and the pancreata were then investigated for hyaluronan and water content, hyaluronan distribution, general morphology and the presence of CD44-positive cells, macrophages, and T lymphocytes.. Hyaluronan accumulated in the edematous interstitium during acute pancreatitis. Twenty-four hours after the induction of pancreatitis, the hyaluronan content of the pancreata had increased by more than 100%. Simultaneously, CD44-positive cells infiltrated the tissue. However, no correlation between hyaluronan and water was seen at any time point.. This study shows that acute pancreatitis is associated with a strong but transient increase in interstitial hyaluronan and an infiltration of CD44-positive cells located mainly in the same region as the accumulated hyaluronan.

Topics: Acute Disease; Amylases; Animals; Ceruletide; Edema; Hyaluronic Acid; Hyaluronoglucosaminidase; Male; Pancreas; Pancreatitis; Rats; Rats, Sprague-Dawley; Water

Topics: Acute Disease; Animals; Ceruletide; Disease Models, Animal; Edema; Humans; Hyaluronic Acid; Pancreatitis; Rats

Whether acute pancreatitis induced by cerulein was aggravated in human interleukin 6 (IL-6) transgenic mice and whether a specific anti-IL-6 receptor antibody improved pancreatitis were investigated. To induce acute pancreatitis, cerulein (50 microg/kg, seven injections) with or without 1 mg/kg lipopolysaccharides (LPS) was injected intraperitoneally every hour. In some mice, a monoclonal anti-IL-6 receptor antibody was administered before the first cerulein injection. The animals were killed 1 hour after the last injection. The pancreatic wet weight induced by cerulein alone was significantly higher in IL-6 transgenic mice compared with wild-type mice, but pretreatment with a specific anti-IL-6 receptor antibody did not reduce interstitial edema. When cerulein was administered with LPS, the pancreatic wet weight increased much more than when pancreatitis was induced by cerulein alone in both genotypes, and pretreatment with the anti-IL-6 receptor antibody decreased the pancreatic edema only in human-IL-6 transgenic mice. These results suggest that anticytokine antibodies may be effective in improving acute pancreatitis.

Topics: Acute Disease; Amylases; Animals; Antibodies, Monoclonal; Ceruletide; Edema; Humans; Interleukin-6; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Organ Size; Pancreas; Pancreatitis; Receptors, Interleukin-6

Adenosine has been shown to modulate various pathophysiologic conditions through receptor-mediated mechanisms. However, the role of adenosine in the pathogenesis of acute pancreatitis has not been described. We examined the effect of adenosine-receptor stimulation or inhibition on the pathologic changes of the pancreas.. Rats received intraperitoneal injections of selective agonists of A1, A2a, and A3 adenosine receptors: 2-chloro-N(6)-cyclopentyladenosine (CCPA), CGS-21680 (CGS), or 1-deoxy-1-[6-[[(3-iodophenyl)methyl]amino]-9H-purin-9-yl]-N-methyl-be ta-D-ribofuranuronamide (IB-MECA), respectively. Serum amylase activity and pathologic changes of the pancreas were evaluated. The effects of a specific A1-receptor antagonist (FK-838) on the pathologic findings of cerulein- and taurocholate-induced pancreatitis were also examined.. Administration of a selective A1 agonist induced hyperamylasemia and morphologic changes in the pancreas characterized by interstitial edema and leukocyte infiltration; neither A2a nor A3 agonist produced such changes. Treatment with an A1-receptor antagonist significantly attenuated the outcome induced by A1 agonist stimulation. In addition, the A1-receptor antagonist significantly ameliorated pancreatic edema in both pancreatitis models, although it did not improve the acinar cell damage of the pancreas or the increase of serum amylase.. Activation of the adenosine A1-receptor pathway may have an important role in the pathogenesis of acute pancreatitis.

Topics: Acute Disease; Adenosine; Amylases; Animals; Ceruletide; Edema; Leukocytes; Male; Pancreas; Pancreatic Diseases; Pancreatitis; Phenethylamines; Purinergic P1 Receptor Agonists; Purinergic P1 Receptor Antagonists; Pyrazoles; Pyridines; Rats; Rats, Wistar; Receptor, Adenosine A3; Receptors, Purinergic P1; Taurocholic Acid

Autodigestion of the pancreas by its own prematurely activated digestive proteases is thought to be an important event in the onset of acute pancreatitis. The mechanism responsible for the intrapancreatic activation of digestive zymogens is unknown, but a recent hypothesis predicts that a redistribution of lysosomal cathepsin B (CTSB) into a zymogen-containing subcellular compartment triggers this event. To test this hypothesis, we used CTSB-deficient mice in which the ctsb gene had been deleted by targeted disruption. After induction of experimental secretagogue-induced pancreatitis, the trypsin activity in the pancreas of ctsb(-/-) animals was more than 80% lower than in ctsb(+/+) animals. Pancreatic damage as indicated by serum activities of amylase and lipase, or by the extent of acinar tissue necrosis, was 50% lower in ctsb(-/-) animals. These experiments provide the first conclusive evidence to our knowledge that cathepsin B plays a role in intrapancreatic trypsinogen activation and the onset of acute pancreatitis.

Topics: Acute Disease; Amylases; Animals; Apoptosis; Cathepsin B; Ceruletide; Disease Models, Animal; Edema; Enzyme Activation; Gene Deletion; Gene Targeting; Humans; Lipase; Mice; Mice, Knockout; Necrosis; Pancreas; Pancreatitis; Phenotype; Trypsinogen

alpha 1-Acid glycoprotein (AAG), a highly negatively charged glycoprotein, well known for its capillary stabilizing effect, was tested in rat models of acute edematous pancreatitis, acute hemorrhagic-necrotizing pancreatitis, and acute respiratory distress syndrome (ARDS). In cerulein-elicited edematous pancreatitis AAG improved histological alterations at 200 mg/kg i.v. and plasma amylase activity at 1800 or 4200 mg/kg i.v. All other parameters (edema, plasma lipase) were not affected in a biologically relevant manner. In glycodeoxycholic acid-induced hemorrhagic-necrotizing pancreatitis AAG was without effect on parameters measured (plasma amylase, plasma lipase activity, histological scores) at 1800 or 4200 mg/kg i.v. At the extremely high dose of 1500 mg/kg i.v. plasma amylase and lipase levels were decreased. In lipopolysaccharide-mediated ARDS, AAG was tested at 50, 200 or 600 mg/kg i.v. AAG, but also the placebo formulation decreased the myeloperoxidase content in the bronchoalveolar lavage fluid. Histological alterations were improved by AAG, however, not by the placebo formulation. Lung water content was not significantly influenced by AAG, whereas Evans blue extravasation was significantly diminished by all three doses of AAG. It is concluded that the edematous pancreatitis is the first in vivo condition with increased extravascular fluid accumulation, in which AAG is not effective. Based on data presented here and literature data, there is evidence for a beneficial effect of AAG in acute lung injury.

Topics: Acute Disease; Animals; Bronchoalveolar Lavage Fluid; Ceruletide; Edema; Glycodeoxycholic Acid; Hemorrhage; Lipopolysaccharides; Lung Diseases; Male; Orosomucoid; Pancreatitis; Rats; Rats, Sprague-Dawley; Respiratory Tract Diseases

Recent evidence suggests that a number of rapid signaling cascades are initiated during secretagogue-induced pancreatitis. However, little is known about the nuclear events. The aim of this study was to explore activation of the transcription factor NF-kappaB/Rel after supramaximal stimulation with the cholecystokinin analogue cerulein in the pancreas.. Nuclear appearance of NF-kappaB/Rel-binding activity was detectable 15 minutes after cerulein injection. The DNA-binding activity consisted of NF-kappaB1 p50, NF-kappaB2 p52, and RelA p65 as judged by supershift assays and Western blot analysis. The onset and termination of NF-kappaB/Rel activation correlated with the degradation and reappearance of IkappaBalpha. Cerulein in supramaximal but not in physiological doses activated NF-kappaB/Rel in vitro. After blocking of NF-kappaB/Rel activation with pyrrolidine dithiocarbamate, the degree of morphological alterations was more pronounced than in controls, serum amylase and lactate dehydrogenase levels were significantly increased, and messenger RNA levels of pancreatitis-associated protein were more strongly induced, reflecting a more severe degree of pancreatitis. Similar results were obtained when N-acetyl-L-cysteine was used as an inhibitor of NF-kappaB activation.. These data show that NF-kappaB/Rel is rapidly activated during cerulein pancreatitis. This activation may induce a self-defending genetic program before the onset of cellular injury, which might prevent higher degrees of damage of pancreatic acinar cells after secretagogue hyperstimulation.

Topics: Acetylcysteine; Amylases; Animals; Antioxidants; Blotting, Northern; Blotting, Western; Ceruletide; DNA Probes; Dose-Response Relationship, Drug; Edema; Free Radical Scavengers; L-Lactate Dehydrogenase; Male; NF-kappa B; Pancreatitis; Pancreatitis-Associated Proteins; Protein Binding; Pyrrolidines; Rats; Rats, Wistar; Thiocarbamates

This study was done to evaluate the possible preventive effects of reactive oxygen species (ROS) scavenger agent desferrioxamine (DFX) and platelet-activating factor (PAF) antagonist agent ginkgo biloba (GB) in an experimental acute pancreatitis model. Seventy-eight CD-1 mice were divided into six groups consisting of 10-13 mice. Induction of pancreatitis was achieved by cerulein injection in groups 2-5. The first group was control, whereas DFX and GB were used alone or in combinations as preventive agents in groups 3-5. DFX or GB were injected to the mice in groups 6 and 7 to evaluate any toxic effect. The assessment of the pancreatic edema and inflammation, the measurement of the amylase and the pancreatic weight and the measurement of the pancreatic tissue oxidative capacity by chemiluminescence method were the parameters to evaluate pancreatitis. Although the results indicate DFX and GB alone or in combinations have significant preventive roles, this was not a complete prevention.

Topics: Acute Disease; Amylases; Animals; Ceruletide; Deferoxamine; Disease Models, Animal; Edema; Free Radical Scavengers; Ginkgo biloba; Inflammation; Leukocytes; Luminescent Measurements; Male; Mice; Pancreas; Pancreatitis; Phytotherapy; Plants, Medicinal; Platelet Activating Factor

Chemotactic peptides bind specifically to receptors on leukocyte membranes. This property makes them prospective vehicles to evaluate inflammation and infection. We used two well-established models of acute pancreatitis to quantitate the binding of the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine-lysine (fMLFK) to leukocytes and its correlation to degree of organ inflammation. Uptake of the (99m)Tc-labeled nicotinyl hydrazine-derivatized chemotactic peptide analog fMLFK-HYNIC was measured in blood, pancreas, lung, and muscle specimens in rats with edematous or necrotizing pancreatitis and was compared with neutrophil sequestration assessed by myeloperoxidase activity and histology. Chemotactic peptide uptake in the pancreas was increased in mild and severe pancreatitis compared with controls, with higher levels in severe than in mild disease, and correlated with tissue myeloperoxidase activity (r = 0.7395, P < 0.001). Increased pulmonary uptake only in severe pancreatitis reflected pancreatitis-induced neutrophil sequestration in the lungs. Muscle uptake was unchanged compared with controls. Edema formation did not affect chemotactic peptide uptake. The data suggest that uptake of chemotactic peptides can contribute to quantitative assessment of neutrophils in localized inflammatory processes and is independent of associated edema formation or microcirculatory compromise.

Topics: Animals; Ceruletide; Disease Models, Animal; Edema; Histocytochemistry; Leukocytes; Male; N-Formylmethionine Leucyl-Phenylalanine; Neutrophils; Nicotinic Acids; Oligopeptides; Pancreas; Pancreatitis; Peroxidase; Rats; Rats, Sprague-Dawley; Technetium Compounds

Since oxygen free radicals and lipid peroxidation have been implicated in the pathogenesis of an early stage of acute pancreatitis, we examined whether melatonin, a recently discovered free-radical scavenger, could attenuate pancreatic injury in Sprague-Dawley rats with cerulein-induced pancreatitis. Acute pancreatitis was induced by four intraperitoneal injections of cerulein (50 microg/kg body wt) given at 1-hr intervals. Thirty minutes after the last cerulein injection, the rats were killed and the degree of pancreatic edema, the level of lipid peroxidation in the pancreas, and serum amylase activity were increased significantly. Pretreatment with melatonin (10 or 50 mg/kg body wt) 30 min before each cerulein injection resulted in a significant reduction in pancreatic edema and the levels of lipid peroxidation. Serum amylase activity, however, was not significantly influenced by either dose of melatonin. Moreover, we found that cerulein administration was associated with stomach edema as well as high levels of lipid peroxidation in the stomach and small intestine, which were also reduced by melatonin. Melatonin's protective effects in cerulein-treated rats presumably relate to its radical scavenging ability and to other antioxidative processes induced by melatonin.

Topics: Acute Disease; Amylases; Animals; Ceruletide; Edema; Free Radical Scavengers; Lipid Peroxidation; Male; Malondialdehyde; Melatonin; Pancreatitis; Rats; Rats, Sprague-Dawley

The effect of B2 receptor bradykinin antagonist icatibant on postcapillary leukostasis, microcirculatory stasis, and tissue necrosis was studied in acute pancreatitis. In rats, pancreatitis was induced by intraductal injection of sodium taurocholate (ST), intravenous caerulein and intraductal infusion of glucodeoxycholic acid (GDOC), or intravenous caerulein infusion alone. Intravital pancreatic microcirculation was observed. Icatibant or vehicle was given 30 min before induction of pancreatitis. In ST pancreatitis, the number of perfused capillaries increased in icatibant-pretreated rats (77% vs. 0% for controls, P < 0.001). Capillary flow was preserved in icatibant-treated rats; total stasis was observed in controls. Mean venular leukocyte adherence decreased in icatibant-treated rats (26% vs. 74% for controls, P < 0.001), and median histopathologic score was reduced (icatibant vs. controls, 5.0 vs. 12 points, respectively; P < 0.01). Kinase II inhibitor captopril or exogenous bradykinin in addition to an otherwise effective dosage of icatibant resulted in microcirculatory stasis, extensive venular leukocyte adherence, and severe histological damage. With a 100 times greater icatibant dosage, this adverse effect was compensated. The beneficial effects of icatibant were also observed in intermediate pancreatitis (caerulein + GDOC). In ST and intermediate pancreatitis, icatibant preserved microcirculation, reduced venular leukocyte adherence, and prevented pancreatic tissue damage. B2 receptor bradykinin-mediated postcapillary leukostasis plays an important role in the pathogenesis of severe forms of acute pancreatitis.

Topics: Acute Disease; Animals; Arterioles; Bradykinin; Bradykinin Receptor Antagonists; Capillaries; Cell Adhesion; Ceruletide; Edema; Female; Hemorrhage; Leukocytes; Microcirculation; Pancreas; Pancreatitis; Rats; Rats, Inbred Lew; Receptor, Bradykinin B2; Regional Blood Flow; Taurocholic Acid; Time Factors; Vasoconstriction; Venules

To investigate the debated role of intracellular trypsinogen activation and its relation to lysosomal enzyme redistribution in the pathogenesis of acute pancreatitis, rats were infused with the cholecystokinin analog caerulein at 5 micrograms.kg-1.h-1 for intervals up to 3 h, and the changes were contrasted with those in animals receiving saline or 0.25 microgram.kg-1.h-1 caerulein. Saline or 0.25 microgram.kg-1.h-1 caerulein did not induce significant changes. In contrast, 5 micrograms.kg-1.h-1 caerulein caused significant hyperamylasemia and pancreatic edema within 30 min. Pancreatic content of trypsinogen activation peptide (TAP) increased continuously (significant within 15 min). TAP generation was predominantly located in the zymogen fraction during the first hour but expanded to other intracellular compartments thereafter. Cathepsin B activity in the zymogen compartment increased continuously throughout the experiments and correlated significantly with TAP generation in the same compartment. Total trypsinogen content increased to 143% with marked interstitial trypsinogen accumulation after 3 h. Supramaximal caerulein stimulation causes trypsinogen activation by 15 min that originates in the zymogen compartment and is associated with increasing cathepsin B activity in this subcellular compartment. However, a much larger pool of trypsinogen survives and accumulates in the extracellular space and may become critical in the evolution of necrotizing pancreatitis.

Topics: Acute Disease; Amylases; Animals; Cathepsin B; Cell Fractionation; Ceruletide; Edema; Enzyme Activation; Kinetics; Male; Oligopeptides; Pancreatitis; Rats; Rats, Sprague-Dawley; Subcellular Fractions; Trypsinogen

Previously we reported that prior administration of lipopolysaccharide (LPS) mitigates subsequently produced cerulein (Cn) pancreatitis. To clarify the mechanism further, the pathological features of Cn pancreatitis were examined in detail after treating rats with very low doses of LPS. LPS pretreatment reduced the formation of pancreatic edema during Cn pancreatitis in a dose- and time-dependent manner. In contrast, the elevation of serum amylase and the histological findings, including acinar cell vacuolization and infiltration of inflammatory cells, were not affected. The lowest dose of LPS, 500 ng/kg, was sufficient to inhibit pancreatic edema formation completely. LPS at a dose of 5 microg/kg was fully effective when it was given from 30 min to 12 h before the induction of pancreatitis. Pretreatment with tumor necrosis factor-alpha (TNF-alpha) inhibited the pancreatic edema in a manner similar to that of LPS. Moreover, the inhibitory effect of LPS was partially attenuated by the administration of anti-TNF-alpha antibody before the injection of LPS. Actinomycin D (0.5 mg/kg) abolished the effect of LPS, whereas cycloheximide (0.5 mg/kg) given alone reduced pancreatic edema formation during pancreatitis. From these results, it was concluded that very low doses of LPS can induce, partially via TNF-alpha, a state refractory to pancreatic edema formation during Cn pancreatitis, and this phenomenon seems to be regulated at the transcriptional level.

Topics: Animals; Ceruletide; Cycloheximide; Dactinomycin; Edema; Lipopolysaccharides; Male; Pancreatic Diseases; Pancreatitis; Rats; Rats, Wistar; Tumor Necrosis Factor-alpha

In acute pancreatitis, two different types of secretory phospholipase A2 (PLA2) have been found: pancreatic type I PLA2 and non-pancreatic type II PLA2. In this study a potent new PLA2 inhibitor effective against type II PLA2 was used in an experimental model of acute pancreatitis.. In 70 rats the efficacy of the compound was analysed in two experimental models of acute pancreatitis: cerulein- and taurocholate-induced acute pancreatitis, imitating mild and severe disease respectively. Serum rat type I PLA2 protein concentration and type I and type II PLA2 catalytic activities were measured while giving the inhibitor therapeutically. In a prophylactic protocol the effect on histology was analysed.. In the taurocholate model, type II PLA2 activity was found to be nine-fold higher than in the cerulein model (P < 0.002), whereas the activity of type I PLA2 was not increased. The inhibitor significantly decreased serum type II PLA2 activity in the taurocholate model of acute pancreatitis (P < 0.05) but type I PLA2 protein concentration and type I PLA2 activity were not affected. The inhibitor also reduced histological tissue damage, with significant differences at 3 and 12 h (P < 0.01).. The PLA2 inhibitor significantly reduced type II PLA2 activity and was able to protect the pancreas against tissue damage. PLA2 inhibition offers the possibility of a treatment for acute pancreatitis.

Topics: Acute Disease; Animals; Ceruletide; Edema; Enzyme Inhibitors; Female; Necrosis; Pancreatitis; Phospholipases A; Phospholipases A2; Rats; Rats, Wistar; Taurocholic Acid

Supramaximal stimulation of the pancreas with the CCK analog caerulein causes acute edematous pancreatitis. In this model, active trypsin can be detected in the pancreas shortly after the start of supramaximal stimulation. Incubation of pancreatic acini in vitro with a supramaximally stimulating caerulein concentration also results in rapid activation of trypsinogen. In the current study, we have used the techniques of subcellular fractionation and both light and electron microscopy immunolocalization to identify the site of trypsinogen activation and the subsequent fate of trypsin during caerulein-induced pancreatitis. We report that trypsin activity and trypsinogen-activation peptide (TAP), which is released on activation of trypsinogen, are first detectable in a heavy subcellular fraction. This fraction is enriched in digestive enzyme zymogens and lysosomal hydrolases. Subsequent to trypsinogen activation, both trypsin activity and TAP move to a soluble compartment. Immunolocalization studies indicate that trypsinogen activation occurs in cytoplasmic vacuoles that contain the lysosomal hydrolase cathepsin B. These observations suggest that, during the early stages of pancreatitis, trypsinogen is activated in subcellular organelles containing colocalized digestive enzyme zymogens and lysosomal hydrolases and that, subsequent to its activation, trypsin is released into the cytosol.

Topics: Acute Disease; Animals; Cathepsin B; Cell Fractionation; Ceruletide; Edema; Enzyme Activation; Immunohistochemistry; Kinetics; Lysosomes; Male; Oligopeptides; Pancreas; Pancreatitis; Rats; Rats, Wistar; Subcellular Fractions; Time Factors; Trypsin; Trypsinogen; Vacuoles

This study was designed to evaluate the protective effect of a peptide leukotriene receptor antagonist, pranlukast hydrate, against pancreatic injuries during acute pancreatitis.. Acute pancreatitis was induced in rats by intravenous infusion of a supramaximal dose of cerulein (5 micrograms/kg h for 4 h). In this model marked hyperamylasemia, a significant increase in pancreatic water content, and a significant increase in pancreatic microvascular leakage of Evans blue dye were observed. Pancreatic subcellular redistribution of the lysosomal enzyme cathepsin B from the lysosomal fraction to the zymogen fraction was also observed.. Pretreatment with pranlukast hydrate at a dose of 10 micrograms/kg (twice, 8 and 4 h before cerulein infusion) significantly inhibited these pancreatic injuries, including hyperamylasemia, increased pancreatic microvascular permeability, and redistribution of cathepsin B in pancreatic acinar cells.. These results suggest that peptide leukotrienes may be involved in the pathogenesis of acute pancreatitis in the early stage of the disease and that peptide leukotriene receptor antagonist might be of therapeutic value for treatment of acute pancreatitis.

Topics: Acute Disease; Amylases; Animals; Body Water; Cathepsin B; Ceruletide; Chromones; Edema; Leukotriene Antagonists; Male; Pancreas; Pancreatic Diseases; Pancreatitis; Rats; Rats, Wistar

Transforming growth factor beta isoforms (TGF beta s) belong to a family of multifunctional regulators of cellular growth and differentiation. They are mitogenic and chemotactic for fibroblasts and are potent stimulators of extracellular matrix production (collagen) and deposition. Upregulation of TGF beta transcription has been reported for several in vivo systems during repair after injury.. To study the expression of the three mammalian isoforms of TGF beta (TGF beta 1-3) and their relation to collagen expression as a marker for fibroblast response in acute oedematous pancreatitis in rats.. Using northern blot analysis and immunohistochemistry, the expression and localisation of TGF beta isoforms, collagen, and amylase were analysed during the course of acute oedematous pancreatitis in rats, experimentally induced by intravenous caerulein infusion.. Induction of acute pancreatitis resulted in a biphasic peak pattern of expression of TGF beta 1, beta 2, and beta 3 mRNA, with a pronounced increase from day 1 to day 3 (sixfold, 2.5-fold, fivefold, respectively) and again from day 5 to day 7 (three-fold, 2.3-fold, 3.5-fold, respectively). The temporal changes in TGF beta mRNA identically paralleled the expression in collagen mRNA. In contrast, amylase mRNA expression, used as a general indicator of acinar cell integrity, was slightly decreased after induction of acute pancreatitis. Immunohistochemical analysis of pancreatitis tissue showed that increased expression of TGF beta s was mainly present in the pancreatic acinar and ductal cells; this was evident within one day after pancreatitis induction.. Overexpression of TGF beta s after induction of acute pancreatitis suggests a role for these proteins in pancreatic repair and remodelling. The increased levels of TGF beta s may help suppress immune activation, and may contribute to the increase in the extracellular matrix including collagen and to the repair of the pancreatic parenchyma.

Topics: Acute Disease; Amylases; Animals; Blotting, Northern; Ceruletide; Collagen; Edema; Gastrointestinal Agents; Gene Expression; Immunohistochemistry; Male; Pancreatitis; Rats; Rats, Wistar; RNA, Messenger; Transforming Growth Factor beta

Lipid peroxidation, which may be involved in the pathogenesis of acute pancreatitis, is usually assessed in vitro or indirectly using antioxidants or free radical scavengers. We assessed lipid peroxidation in an in vivo model by measuring ethane exhalation in two models of acute pancreatitis. Edematous acute pancreatitis was induced by a supramaximal intraperitoneal injection of cerulein. Necrotizing acute pancreatitis was induced by retrograde infusion of sodium taurocholate into the pancreaticobiliary duct. Rats were placed in closed chambers and ethane exhalation was measured in aliquots. Ethane exhalation was significantly increased (p < 0.002) in cerulein (n = 12)- but not in taurocholate (n = 6)-induced pancreatitis compared to controls (n = 12 and 6, respectively). Our results suggest that free radicals may play a role in the pathogenesis of edematous pancreatitis but do not play an important role in the progression to necrotizing pancreatitis.

Topics: Acute Disease; Amylases; Animals; Ceruletide; Disease Models, Animal; Edema; Ethane; Lipase; Lipid Peroxidation; Male; Necrosis; Organ Size; Pancreas; Pancreatitis; Rats; Rats, Sprague-Dawley

The importance of interleukin-1beta (IL-1beta) in the pathogenesis of acute pancreatitis has been demonstrated by dramatic attenuation of pancreatic destruction and significant increases in survival when its actions are inhibited. The pancreas has been shown to be a major producer of IL-1beta during pancreatitis but the cell(s) of origin remains unknown. Hypothesizing that infiltrating leukocytes contribute substantially, the intrapancreatic production of IL-1beta was examined after specific leukocyte populations were manipulated in vivo prior to the induction of pancreatitis. Sixty-four adult male Swiss mice were assigned to one of four groups 48 hr prior to induction of pancreatitis: (1) PMN depletion via anti-murine PMN antiserum. [PMN-d], (2) macrophage (Mphi) depletion via anti-macrophage antiserum [Mphi-d], (3) PMN and Mphi depletion [PMN+Mphi-d], and (4) Immunocompetent Pancreatitis. Edematous pancreatitis was induced in all experimental groups by caerulein (50 microg/kg/hr ip X 4). Animals were sacrificed 6 hr after induction of pancreatitis with severity determined by blind histologic grading and serum amylase, lipase, and interleukin-6 (IL-6) levels. Intrapancreatic IL-1beta production was determined by immunohistochemistry and semiquantitative differential RT-PCR. Pancreatitis developed in all animals receiving caerulein; however, leukocyte-depleted animals showed significantly attenuated levels of serum amylase, lipase, and IL-6, as well as lower histologic severity scores. Similarly, pancreatitis induction in immunocompetent mice showed pancreatic infiltration of IL-1beta-producing cells, whereas the leukocyte-depleted animals had significantly decreased numbers (PMN+Mphi-d < Mphi-d < PMN-d). IL-1beta mRNA was upregulated in all animals developing pancreatitis with significantly lower levels seen in the leukocyte-depleted groups. We conclude that infiltrating leukocytes, both neutrophils and macrophages, are responsible for the majority of intrapancreatic IL-1beta production during acute pancreatitis. The elimination of leukocytes and their products, including IL-1beta, significantly decreases the severity of pancreatic destruction.

Topics: Acute Disease; Amylases; Animals; Base Sequence; Ceruletide; DNA Primers; Edema; Gene Expression; Immunohistochemistry; Interleukin-1; Interleukin-6; Leukocytes; Macrophages; Male; Mice; Molecular Sequence Data; Neutrophils; Pancreas; Pancreatitis; Polymerase Chain Reaction; Reference Values; RNA, Messenger; Time Factors

Acute pancreatitis is characterized by hyperamylasemia, pancreatic edema, and the presence of activated digestive enzymes within the pancreas. The secretagogue-induced model of acute pancreatitis is also characterized by pancreatic acinar cell vacuolation, subcellular redistribution of lysosomal hydrolases, and a fall in pancreatic glutathione levels. We have performed time-dependence studies to determine the sequence with which these phenomena appear and to establish their cause-and-effect relationship. Evidence of lysosomal enzyme redistribution and trypsinogen activation within the pancreas could be detected within 10-15 min of the onset of supramaximal secretagogue stimulation, while hyperamylasemia (30 min), pancreatic edema (60 min), and acinar cell vacuolation (60 min) occurred at later times. Pancreatic glutathione levels were either unchanged (15 and 30 min) or elevated (60 min) during the early times of supramaximal stimulation and were only noted to be decreased at a later time. These results support the conclusion that intrapancreatic digestive enzyme activation, possibly occurring by a mechanism involving lysosomal hydrolase redistribution, is an early and likely a critical event in the evolution of secretagogue-induced pancreatitis but that glutathione depletion is neither early nor critical to the evolution of this model of pancreatitis.

Topics: Amylases; Animals; Cathepsin B; Ceruletide; Edema; Enzyme Activation; Glutathione; Male; Pancreas; Pancreatic Diseases; Pancreatitis; Rats; Rats, Wistar; Subcellular Fractions; Trypsinogen

One of the vasoactive peptides that has been implicated in the progression from edematous to necrotizing pancreatitis is bradykinin. We have investigated the effect of bradykinin administration and bradykinin inhibition on an edematous model of acute pancreatitis in rats (10 micrograms/kg/h of caerulein i.v.). Within six hours i.v. bradykinin reduced circulating serum amylase levels significantly but neither affected tissue edema nor morphology. A bradykinin antagonist (HOE-140), on the other hand, reduced pancreatic edema by 70% and converted edematous pancreatitis into a hemorrhagic and necrotizing variety of the disease. In further experiments we determined the time course and the minimal dosage required for the induction of this severe and non-invasive disease variety. A single dose of caerulein (40 micrograms/kg i.p.) together with a single administration of the bradykinin antagonist HOE-140 (100 micrograms/kg s.c.) consistently resulted in hemorrhagic necrosis of the pancreas within six hours. We conclude that this simple protocol allows for the non-invasive induction of a vascular model of necrotizing pancreatitis and appears ideally suited to study the development of this severe form of the disease.

Topics: Acute Disease; Animals; Anti-Inflammatory Agents, Non-Steroidal; Bradykinin; Ceruletide; Disease Models, Animal; Edema; Hemorrhage; Male; Necrosis; Pancreatitis; Rats; Rats, Wistar

To use mice to examine the effects of cyclosporine and tacrolimus (FK 506) on two forms of acute pancreatitis often seen after clinical organ transplantation.. In the first experiment, male CD-1 mice received cyclosporine (10 mg/kg), tacrolimus (0.32 mg/kg), or saline solution (control) subcutaneously once a day for 10 days. On the 11th day, acute edematous pancreatitis was induced by ceruletide (cerulein). In the second experiment, female ICR mice were fed with a choline-deficient, ethionine-supplemented (CDE) diet for 72 hours to induce necrotizing pancreatitis. After 30 hours on the CDE diet, the mice received cyclosporine (10 mg/kg), tacrolimus (0.32 mg/kg), or saline solution (control) subcutaneously twice daily for 3 days.. The pancreatic dry-to-wet weight ratios after ceruletide injections significantly decreased in mice treated with cyclosporine but did not with tacrolimus. Cyclosporine also significantly increased serum amylase levels, but tacrolimus did not. Cyclosporine or tacrolimus alone did not produce pancreatitis. In the CDE diet groups there was a significant difference in survival among the cyclosporine-treated, the tacrolimus-treated, and the control groups.. Cyclosporine or tacrolimus given alone does not induce acute pancreatitis. In contrast, cyclosporine can adversely affect the course of acute edematous pancreatitis, and both immunosuppressants may worsen the survival of mice with acute hemorrhagic necrotizing pancreatitis. This study also demonstrated that the deteriorating effect of tacrolimus is less potent than that of cyclosporine.

Topics: Acute Disease; Animals; Ceruletide; Choline Deficiency; Cyclosporine; Edema; Ethionine; Female; Male; Mice; Necrosis; Pancreatitis; Tacrolimus

Fulminant acute pancreatitis is a disease of complex origin that results in activation of several of the proinflammatory cytokines. Because interleukin-1 (IL-1) is an integral early component of the acute inflammatory process, the use of an IL-1 receptor antagonist (IL-1ra) was investigated in experimental acute pancreatitis to determine the therapeutic potential of proximal cytokine blockade and to further establish the role of inflammatory cytokines in the pathogenesis of acute pancreatitis.. IL-1ra was administered in escalating doses either before or after acute edematous, necrotizing pancreatitis was induced in adult male mice by injection of cerulein. The severity of pancreatitis was quantified by serum amylase, lipase, interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) levels, pancreatic wet weight, and blinded histologic grading.. Administration of medium (10 mg/kg) and high (100 mg/kg) doses of IL-1ra either before or after the induction of pancreatitis significantly decreased the expected rise in pancreatic wet weight, lipase, IL-6, and TNF-alpha (all, p < 0.01). Serum amylase was significantly reduced when IL-1ra was administered in either dosage before (p < 0.05), but not after, induction of pancreatitis. Pancreatic edema, necrosis, and inflammatory cell infiltrate were significantly diminished (p < 0.05) by histologic grading in all animals receiving medium or high doses of IL-1ra. Low doses of IL-1ra (1.0 mg/kg) had modest effects if given before, but no effect if given after, induction of pancreatitis.. The proinflammatory cytokines IL-6 and TNF-alpha are elevated during experimental acute pancreatitis and correlate well with the severity of local pancreatic destruction. Blockade of the cytokine cascade at the level of the IL-1 receptor before or soon after induction of pancreatitis significantly attenuates the rise in these cytokines and is associated with decreased severity of pancreatitis and reduced intrinsic pancreatic damage.

Topics: Acute Disease; Amylases; Animals; Ceruletide; Edema; Interleukin 1 Receptor Antagonist Protein; Interleukin-1; Interleukin-6; Lipase; Male; Mice; Necrosis; Organ Size; Pancreas; Pancreatitis; Receptors, Interleukin-1; Recombinant Proteins; Sialoglycoproteins; Single-Blind Method; Tumor Necrosis Factor-alpha

Nitric oxide (NO) has been implicated to regulate pancreatic circulation, promote capillary integrity, and inhibit leukocyte adhesion. We investigated the role of NO in the development of pancreatitis. Nitro-L-arginine, an inhibitor of NO synthase, in total dose of 35 mg/kg body wt was infused in the rats with edematous pancreatitis induced by two intraperitoneal injections of cerulein (20 micrograms/kg). L-Arginine (125 or 250 mg/kg), a NO donor was intravenously administered twice in the rats with hemorrhagic pancreatitis induced by water-immersion stress plus two intraperitoneal injections of cerulein (40 micrograms/kg). The degree of pancreas edema, serum amylase levels, and histologic alterations were investigated. Nitro-L-arginine exacerbated cerulein-induced pancreatitis and caused a decrease in pancreatic blood flow. L-Arginine ameliorated the severity of hemorrhagic pancreatitis dose dependently and improved the pancreatic blood flow. These findings suggest that NO could confer protection against the development of hemorrhagic pancreatitis, probably through improvement of the pancreatic microcirculation.

Topics: Acute Disease; Animals; Arginine; Ceruletide; Drug Interactions; Edema; Enzyme Inhibitors; Gastrointestinal Hemorrhage; Male; Nitric Oxide; Nitric Oxide Synthase; Nitroarginine; Pancreas; Pancreatitis; Random Allocation; Rats; Rats, Sprague-Dawley; Time Factors

Extraintestinal trypsinogen activation peptides (TAP) have been shown to correlate with severity of acute pancreatitis in humans as well as in various animal models. Ischemia superimposed on experimental pancreatitis, however, increases acinar cell injury without increasing TAP in plasma. We speculated that TAP generated in the pancreas might not reach the circulation in necrotizing pancreatitis due to decreased pancreatic perfusion. To test the hypothesis that generation of TAP in plasma is related to pancreatic perfusion and that plasma TAP may therefore underestimate acinar cell injury in necrotizing disease, we correlated TAP in pancreatic tissue and body fluids with capillary pancreatic blood flow in necrotizing and edematous pancreatitis. The ratio between necrosis and TAP in tissue was similar in both models; the ratio between TAP in plasma and tissue, however, was significantly lower in necrotizing pancreatitis, indicating that a certain amount of TAP generated in the pancreas did not reach the circulation. Decreased pancreatic perfusion found in necrotizing pancreatitis was consistent with this finding. Our data suggest that TAP in tissue is most reliable to indicate severity of acute pancreatitis, whereas plasma TAP may underestimate pancreatic injury in necrotizing disease due to decreased pancreatic perfusion.

Topics: Acute Disease; Animals; Ceruletide; Disease Models, Animal; Edema; Glycodeoxycholic Acid; Male; Microcirculation; Necrosis; Oligopeptides; Pancreas; Pancreatitis; Rats; Rats, Sprague-Dawley; Trypsinogen

Little is known about the pathophysiological factors that determine the clinical severity of acute pancreatitis. Because impairment of pancreatic circulation and oxygenation is associated with greater disease severity and morphological damage in experimental pancreatitis it has been suggested that various vasoactive mediators might participate in the progression from the oedematous to the necrotising variety of the disease. This study used an animal model of acute pancreatitis induced by intravenous caeruleint (10 micrograms/kg/h for up to six hours), which does not entail either haemorrhage or significant necrosis of the pancreas. This study considered whether the administration or the inhibition of either nitric oxide, bradykinin, or adrenergic mediators can convert this mild variety into haemorrhagic and necrotising pancreatitis. Neither nitric oxide nor catecholamines were involved in the progression from oedematous to haemorrhagic pancreatitis. Their substitution, activation, and inhibition all failed to change the severity of the disease process. Bradykinin alone seemed to be critically involved in the pathogenesis of pancreatic haemorrhage and necrosis. However, the inhibition of bradykinin and not its activation or substitution increased the severity of the disease.

Topics: Acute Disease; Animals; Arginine; Bradykinin; Catecholamines; Ceruletide; Edema; Labetalol; Male; Microcirculation; Microscopy, Electron, Scanning; Necrosis; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitroglycerin; Pancreas; Pancreatitis; Phenylephrine; Rats; Rats, Wistar

During acute pancreatitis, experimental data obtained in vitro suggested that pancreatic lipase generates nonesterified fatty acids (NEFA), noxious for acinar cells, by hydrolysis of pancreatic or circulating triglycerides. The purpose of this work was to determine whether experimentally induced high plasma NEFA levels do indeed aggravate in vivo cerulein-induced pancreatitis. Anesthetized Sprague-Dawley rats received cerulein and were simultaneously infused intravenously with either saline or a triglyceride + heparin mixture (TGH) in order to increase the amount of circulating NEFA. Plasma NEFA increased about fourfold (3.02 +/- 0.28 mumol/liter) in animals infused with TGH with respect to controls (0.75 +/- 0.05 mumol/liter). In rats receiving cerulein + TGH, pancreatic enzyme levels in plasma, ascites, and histological alterations of the pancreas did not differ from those observed in the rats receiving cerulein + saline. There was less macroscopic pancreatic edema (P < 0.01) in the cerulein + TGH group than in the cerulein + saline group. Separate infusion of either heparin alone or of triglycerides alone had no effect. We conclude that high levels of circulating NEFA do not aggravate cerulein pancreatitis in rats and may even induce a protective effect.

Topics: Acute Disease; Animals; Ceruletide; Edema; Fatty Acids, Nonesterified; Heparin; Lipase; Male; Pancreas; Pancreatitis; Rats; Rats, Sprague-Dawley; Triglycerides

This study was designed to investigate the role of nitric oxide (NO) in the formation of pancreatic edema in caerulein-induced pancreatitis in rats. Pancreatitis was produced by two intraperitoneal injections of caerulein, and plasma amylase concentration, pancreatic edema index (pancreatic wet weight/body weight), and Evans blue extravasation (as a measure of vascular permeability) were evaluated 5 h after the first injection. Four doses (1, 2.5, 5, and 10 mg/kg) of NG-nitro-L-arginine (L-NNA), an NO synthase inhibitor, were subcutaneously administered at -0.5, 0.5, 1.5, 2.5, and 3.5 h after the first injection of caerulein. L-NNA significantly lowered the edema index, the wet/dry weight ratio of the pancreas, and Evans blue extravasation in the rats with pancreatitis. The maximal effect was obtained by L-NNA at a dose of 2.5 mg/kg; this inhibited the increase in pancreatic edema formation from the control value by 60%-70%. Intraperitoneal injections (20 mg/kg, five times) of L-arginine, a substrate for NO production, partly reversed the L-NNA-induced inhibition of pancreatic edema formation, but D-arginine, an enantiomer of L-arginine, did not show any effect. Plasma amylase concentrations were not significantly affected by any dose of L-NNA, nor were they affected by L- or D-arginine. These findings strongly suggest that endogenous NO plays an important role in the formation of pancreatic edema in caerulein-induced pancreatitis in rats, probably by increasing vascular permeability and protein extravasation.

Topics: Acute Disease; Amylases; Animals; Arginine; Capillary Permeability; Ceruletide; Dose-Response Relationship, Drug; Edema; Enzyme Inhibitors; Evans Blue; Male; Nitric Oxide; Nitroarginine; Pancreatitis; Rats; Rats, Wistar

The role of oxygen-derived free radicals in the pathogenesis of acute pancreatitis was studied in a new model of acute hemorrhagic pancreatitis and cerulein-induced edematous pancreatitis in rats. Hemorrhagic pancreatitis was produced by administering two intraperitoneal doses of cerulein [40 micrograms/kg body weight (BW)] at 1-h intervals following water immersion stress applied for 5 h. Edematous pancreatitis was induced by injecting cerulein as described but without water immersion. Five hours after the first injection of cerulein, pancreatic edema and elevation of serum amylase level were more marked in the animals with hemorrhagic than with edematous pancreatitis. Five hours after the first injection of cerulein, marked hemorrhage and venous dilatation were observed only in those with hemorrhagic pancreatitis. Local pancreatic blood flow decreased to approximately 60% of control values in the animals with edematous pancreatitis, and to approximately 30% of control values in those with hemorrhagic pancreatitis. To evaluate the involvement of oxygen radicals, some rats received three intraperitoneal injections of superoxide dismutase (SOD 10,700 U/kg BW) and catalase (132,000 U/kg BW) beginning 15 min before the first injection of cerulein and repeated at 1-h intervals. No significant effect of free radical scavengers was observed on the edematous pancreatitis. However, in hemorrhagic pancreatitis, treatment with SOD and catalase completely suppressed the hemorrhage and venous dilatation of the pancreas, significantly reduced the pancreatic wet weight and the serum amylase level, and reduced the histologic alterations. However, after treatment with SOD and catalase, no differences were observed in local pancreatic blood flow.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Amylases; Animals; Catalase; Ceruletide; Edema; Free Radicals; Hemorrhage; Immersion; Male; Organ Size; Oxygen; Pancreas; Pancreatitis; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Stress, Physiological; Superoxide Dismutase

Pancreatic morphology and amylase release from isolated pancreatic acini in response to caerulein was studied in the course of an experimental bile induced acute pancreatitis without acinar necrosis. The inflammation was induced by retrograde microinfusion of 25 microliters bile into the rat bile pancreatic duct. A dissociation between functional and structural findings was seen. One hour after the bile injury, there was a transient change in acinar cell function. The response to stimulation by caerulein was reduced by 50%, whereas the sensitivity to caerulein was normal. There was oedema and an initial leucocyte infiltration of the gland. Six hours, one day, three days, and seven days after the bile injury, there was an acute interstitial oedematous pancreatitis with a modest polymorphonuclear leucocyte infiltration of the interstitium and widespread acinar vacuolisation. Morphological changes were most pronounced at the third postoperative day. Acinar amylase release, however, was normal both in terms of sensitivity and responsiveness to stimulation. These results show that bile injury may result in an initial disturbance of acinar cell function. Normal acinar amylase release prevailing in the course of the inflammation suggests that disturbance of the acinar amylase secretory response is not a primary stimulant of the inflammation before the development of acinar necrosis.

Topics: Amylases; Animals; Bile; Ceruletide; Disease Models, Animal; Edema; Female; In Vitro Techniques; Pancreas; Pancreatitis; Rats; Rats, Wistar; Time Factors

Pancreatic enzyme secretion is inhibited during acute pancreatitis, resulting in an increase in acinar zymogen content. Since the premature activation of zymogens has been assigned a central role in the pathogenesis of acute pancreatitis, minimizing the amount of stored zymogens might lead to less severe acute pancreatitis. Inhibition of enzyme synthesis or stimulation of enzyme secretion would result in reduction of zymogen stores. Opiates have a varying effect on pancreatic secretion, depending on the dosage, site of administration, and presence of pancreatic stimulants. The effect of opiates and acute pancreatitis on individual pancreatic enzyme synthesis is unknown. The following study was undertaken in order to examine the effects of an opiate on pancreatic enzyme secretion and synthesis during experimental acute pancreatitis. Four groups of rats were studied. Group I received cerulein (25 micrograms/kg); group II received an opiate, buprenorphine (BPN, 0.5 mg/kg); and group III received cerulein and BPN. Drugs were dissolved in gelatin/saline and injected subcutaneously. A control group (group IV) received only gelatin/saline. Rats were sacrificed 4 hr after injection, and pancreatic mass was measured. Pancreatic acini were prepared and assayed for amylase and DNA content. Amylase, trypsinogen, chymotrypsinogen and lipase synthesis, and amylase secretion were measured for 2 hr. Results showed that, compared to controls, acini of rats with AP had increased amylase content, a finding consistent with decreased in vivo amylase secretion. Total protein and individual enzyme synthesis rates were significantly lower in the acini of the rats with AP than in those of the controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Acute Disease; Amylases; Animals; Buprenorphine; Ceruletide; Chymotrypsinogen; Edema; Lipase; Male; Pancreas; Pancreatitis; Rats; Rats, Inbred Strains; Trypsinogen

Impairment of pancreatic microcirculation has often been advocated as one pathogenic mechanism in necrotizing pancreatitis. In contrast, data on pancreatic capillary perfusion in edematous pancreatitis are scarce. It was the aim of this experimental study to compare changes in pancreatic microcirculation in edematous and necrotizing pancreatitis. Twelve rabbits were allocated to two groups. Two different models of acute pancreatitis were used. Edematous pancreatitis was elicited by intravenous administration of cerulein (25 micrograms/kg/hr) (N = 6). Necrotizing pancreatitis of the biliary type was induced by pressure-controlled intraductal infusion of a mixture of taurocholate, trypsin, and blood (N = 6). Pancreatic microcirculation was quantified by means of intravital microscopy assessing functional capillary density, blood cell velocity, and distribution of the plasma marker FITC-dextran 70. Systemic hemodynamics were maintained at baseline values by fluid administration. Regardless of edema or necrosis, pronounced extravasation of FITC-dextran was recorded in the early stage of pancreatitis. In cerulein-induced pancreatitis, hyperemia developed as indicated by an increase in blood cell velocity in the presence of homogeneous capillary perfusion. In contrast, a progressive reduction of the number of perfused capillaries was detected in necrotizing pancreatitis. In conclusion, pancreatic microvascular perfusion may be regarded as an important pathogenetic factor for the determination of acute pancreatitis.

Topics: Acute Disease; Animals; Capillary Permeability; Ceruletide; Edema; Ischemia; Microcirculation; Necrosis; Pancreas; Pancreatitis; Rabbits

Bacterial infection of pancreatic necrosis is thought to be a major determinant of outcome in acute necrotizing pancreatitis. The determinants and possibilities for prophylaxis are unknown and difficult to study in humans.. The time course of bacterial infection of the pancreas in a rodent model of acute necrotizing pancreatitis was characterized. The authors ascertained if there is a correlation with the degree of necrosis.. Acute pancreatitis (AP) of graded severity was induced under sterile conditions by an intravenous infusion of cerulein (5 micrograms/kg/hr) for 6 hours (mild AP), or a combination of intravenous cerulein with an intraductal infusion of 10-mM glycodeoxycholic acid (0.2 mL for 2 min for moderate AP, 0.5 mL for 10 min for severe AP). Sham-operated animals (intravenous and intraductal NaCl 0.9%) served as controls. Ninety-six hours after induction, animals were killed for quantitative bacterial examination and histologic scoring of necrosis. In addition, groups of animals with severe AP were investigated at 12, 24, 48, 96, and 144 hours.. No significant pancreatic necrosis was found in control animals (0.3 +/- 0.1) or animals with mild AP (0.6 +/- 0.1) killed at 96 hours. Necrosis scores were 1.1 +/- 0.2 for animals with moderate AP and 1.9 +/- 0.2 for animals with severe AP. Control animals did not develop significant bacterial infection of the pancreas (> or = 10(3) CFU/g). At 96 hours, the prevalence of infection was 37.5% in animals with mild AP and 50% in animals with moderate AP. In animals with severe AP, infection of the pancreas increased from 33% in the first 24 hours to 75% between 48 and 96 hours (p < 0.05). The bacterial counts and the number of different species increased with time and was maximal (> 10(11) CFU/g) at 96 hours.. Bacterial infection of the pancreas in rodent AP increases during the first several days, and its likelihood correlates with the severity of the disease. This model, which closely mimics the features of human acute pancreatitis, provides a unique opportunity to study the pathogenesis of infected necrosis and test therapeutic strategies.

Topics: Acute Disease; Animals; Bacterial Infections; Ceruletide; Colony Count, Microbial; Disease Models, Animal; Edema; Enterococcus; Escherichia coli Infections; Glycodeoxycholic Acid; Gram-Positive Bacterial Infections; Leukocytes; Male; Necrosis; Pancreas; Pancreatitis; Rats; Rats, Sprague-Dawley; Staphylococcal Infections; Survival Rate; Time Factors

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 using 3H-labeled E3123 showed diffuse intracellular distribution of E3123, and the radioactivity of 3H-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 severity of early intracellular alterations in cerulein-induced acute pancreatitis.

Topics: Acute Disease; alpha-Amylases; Animals; Cathepsin B; Ceruletide; Edema; Guanidines; Male; Pancreatitis; Rats; Rats, Wistar; Serine Proteinase Inhibitors; Subcellular Fractions; Trypsin; Vacuoles

Although intracellular protease activation is thought to be an early event in acute pancreatitis, factors determining progression from edematous to necrotizing pancreatitis are largely unknown. With enterokinase as a probe and an immunoassay quantifying free trypsinogen activation peptides (TAP), we sought evidence for the presence of interstitial trypsinogen in edematous pancreatitis and documented the effects of its ectopic activation.. Edematous pancreatitis in the rat was induced by supramaximal stimulation with cerulein (5 micrograms/kg/hr) and coupled with enterokinase infused into the pancreatic duct at 30 mm Hg. Blue dextran infusion at this pressure corroborated interstitial delivery. Rats with no stimulation, maximal physiologic stimulation (0.25 microgram/kg/hr of cerulein), or intraductal saline infusion served as controls. TAP levels measured by enzyme-linked immunosorbent assay, 6-hour survival, and histopathology were used as end points.. Intraductal enterokinase infusion alone or in combination with maximal physiologic stimulation generated only slight increases in TAP level and no or minimal pancreatic injury. In contrast, enterokinase superimposed on edematous pancreatitis (supramaximal cerulein stimulation) produced fulminant pancreatitis and rapid death of all animals within 6 hours. Pancreatic histopathology showed severe intrapancreatic hemorrhage, acinar inflammation, and necrosis. TAP levels were significantly higher in plasma (p = 0.02), urine (p = 0.05), and ascites (p < 0.001) when compared with all other groups.. In edematous pancreatitis a large pool of trypsinogen accumulates in the interstitial space. Activation of these proenzymes leads to catastrophic consequences and may underlie progression from mild to necrotizing pancreatitis.

Topics: Animals; Ceruletide; Edema; Enteropeptidase; Enzyme Activation; Male; Necrosis; Oligopeptides; Pancreatitis; Rats; Rats, Sprague-Dawley; Trypsinogen

Edematous pancreatitis was induced in 12 male Sprague-Dawley rats using supramaximal doses of the cholecystokinin analogue cerulein (5 micrograms/kg per hour). The microvasculature of the pancreas, liver, and kidney was examined using scanning electron microscopy of microvascular corrosion casts in 12 test animals and four controls at intervals of 30 minutes, 1 hour, 2 hours, and 4 hours. Distortion of the pancreatic and hepatic microvasculature was seen as early as 30 minutes and progressed during the study period. The renal vasculature remained normal throughout. Light microscopic analysis revealed no morphologic abnormalities in the walls of the pancreatic, hepatic, or renal microvasculature. This study demonstrates that cerulein-induced pancreatitis is associated with marked distortion of the pancreatic and hepatic microvasculature; the abnormalities start early in the disease and progress during the study period.

Topics: Animals; Capillaries; Ceruletide; Cytoplasmic Granules; Edema; Enzyme Precursors; Erythrocytes; Kidney; Liver; Male; Microcirculation; Pancreas; Pancreatitis; Rats; Rats, Sprague-Dawley; Time Factors; Vacuoles

The effect of taxol, which is a microtubule stabilizer, was examined in a model of acute edematous pancreatitis induced in rat by the administration of caerulein. Prophylactic administration of taxol ameliorated inhibition of pancreatic secretion, increased level of serum amylase, pancreatic edema, and histological alterations in this model. Immunofluorescence studies revealed that taxol stabilized the arrangement of microtubules by the action of promoting tubulin polymerization and prevented inhibition of pancreatic digestive enzyme secretion. In isolated rat pancreatic acini, taxol reversed the inhibition of amylase secretion induced by supramaximal concentrations of cholecystokinin octapeptide and did not affect the binding of cholecystokinin octapeptide to its receptor. The results obtained in this study suggest that microtubule disorganization is the initiating event in caerulein-induced pancreatitis and that the inhibition of pancreatic digestive enzyme secretion by interfering with intracellular vesicular transport due to microtubule disorganization causes caerulein-induced pancreatitis.

Topics: Acute Disease; Alkaloids; Amylases; Animals; Cell Separation; Ceruletide; Edema; Fluorescent Antibody Technique; Male; Microtubules; Paclitaxel; Pancreas; Pancreatitis; Rats; Receptors, Cholecystokinin; Sincalide; Trypsin; Tubulin

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.

Topics: Acute Disease; Amylases; Animals; Body Water; Cathepsin B; Ceruletide; Edema; Gabexate; Guanidines; L-Lactate Dehydrogenase; Lysosomes; Male; Pancreas; Pancreatitis; Rats; Rats, Inbred Strains; Serine Proteinase Inhibitors

Rats were chronically fed either an ethanol-containing diet (36% of total calories derived from alcohol) or a pair-fed, control diet (no alcohol) for 8 wk, and acute pancreatitis (AP) was subsequently induced by a 3-h i.v. infusion of caerulein (CR) at a dose of 5 micrograms/kg/hr. CR-induced AP in control rats (no alcohol) was characterized by a significant elevation in serum lipase content, pancreatic interstitial edema, infrequent occurrences of karyorrhexis, and the appearance of vacuoles in acinar cells. Chronic feeding of the ethanol diet followed by treatment with CR resulted in increases in serum lipase content, interstitial edema, karyorrhexis, and acinar vacuolization that were significantly greater than that seen in rats fed the control diet and treated with CR. It is concluded that chronic ethanol intake in the rat intensifies AP that is subsequently induced by CR.

Topics: Acute Disease; Alcoholism; Animals; Ceruletide; Disease Models, Animal; Edema; Lipase; Lysosomes; Male; Pancreas; Pancreatitis; Rats; Rats, Inbred Strains; Vacuoles

The pathogenesis of acute pancreatitis is incompletely defined, but the outcome is determined in part by an acute inflammatory process. Pancreatitis-associated inflammation appears to play a role in the local retroperitoneal injury as well as in the associated dysfunction of remote organs such as the lung. Tumor necrosis factor (TNF) appears to be a proximal mediator of the inflammatory response. In this study, anti-TNF antibody was administered to rats with caerulein-induced pancreatitis to determine if the observed increases in pancreatic and pulmonary microvascular permeability were related to plasma TNF activity. In contrast to the expected findings, blockade of TNF activity was found to increase the amount of edema formation in both the pulmonary and pancreatic microvascular beds. The mechanism is not known; however, blockade of TNF-induced down regulation of phagocytic cell activity, ablation of TNF-dependent feedback inhibition of other cytokines, failure of induction of endogenous antioxidant systems, or inactivation of the TNF control of microvascular tone are all possible explanations. This is potentially an important observation as clinical strategies are now being developed to modify the inflammatory response in ways presumed advantageous to an injured host.

Topics: Acute Disease; Animals; Antibodies; Ceruletide; Edema; Male; Pancreatic Diseases; Pancreatitis; Pulmonary Edema; Rats; Rats, Inbred Strains; Tumor Necrosis Factor-alpha

Acute edematous pancreatitis was induced in Wistar male rats by iv infusion of cerulein (CR) in the dose of 5.10(-6)g.kg-1.h-1 during 3 or 6 h. The effect of BN 52021--platelet activating factor (PAF) receptor antagonist, against this model of disease was examined. BN 52021 was applied iv as a bolus injection in the dose of 5.10(-3)g.kg-1 at 0 time. Treatment with this agent significantly ameliorates cerulein-induced acute pancreatitis in rats. The effect of BN 52021 was expressed by significant reduction of pancreas edema, diminution of hyperamylasemia, lack of superoxide dismutase activity depletion, and inhibition of lipid peroxidation in pancreatic tissue. These changes were accompanied by significant reduction of acinar cells vacuolization and remarkable inhibition of infiltration with inflammatory cells in the interacinar space. We suppose that beneficial effect of BN 52021 against cerulein-induced acute pancreatitis in rats depends on the prevention of inflammatory cells activation and subsequent generation of oxygen radicals within pancreatic tissue.

Topics: alpha-Amylases; Animals; Ceruletide; Diterpenes; Edema; Free Radicals; Ginkgolides; Lactones; Lipid Peroxidation; Male; Oxygen; Pancreatitis; Platelet Activating Factor; Rats; Rats, Inbred Strains; Superoxide Dismutase

Topics: Acute Disease; Animals; Ceruletide; Edema; Hemorrhage; Pancreas; Pancreatitis; Rats; Stress, Physiological

There are few observations of in vivo pancreatic secretory changes that accompany acute pancreatitis. We hypothesized that acute pancreatitis impairs pancreatic exocrine function. We developed a conscious-rat experimental preparation with gastric, duodenal, bile, and pancreatic fistulas. We studied cholecystokinin-stimulated pancreatic secretion in conscious rats before and after inducing acute pancreatitis with supramaximal administration of caerulein--5 micrograms/kg/hr intravenously for 6 hours. Marked hyperamylasemia developed in all rats immediately after administration of caerulein. Basal and cholecystokinin-stimulated pancreatic juice flow and protein (enzyme) secretion decreased significantly 24 hours after acute pancreatitis was induced even though plasma amylase returned to basal levels. We conclude that acute pancreatitis markedly impairs pancreatic secretion.

Topics: Acute Disease; Amylases; Animals; Ceruletide; Edema; Pancreas; Pancreatitis; Rats; Rats, Inbred Strains; Sincalide

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.

Topics: Acid Phosphatase; Acute Disease; Alprostadil; Amylases; Animals; Ceruletide; Chymotrypsin; Edema; Glucuronidase; Male; Microscopy, Electron; Misoprostol; Organ Size; Pancreatic Diseases; Pancreatitis; Prostaglandins E, Synthetic; Rats; Rats, Inbred Strains

The purpose of this study was to investigate whether stress plays a role, morphologically and enzymatically, in the development of severe pancreatitis in rats. Acute hemorrhagic pancreatitis was induced by two intraperitoneal injections of cerulein (40 micrograms/kg body wt) at intervals of 1 h under water-immersion stress for 5 h, whereas water-immersion stress alone did not induce any morphologic and enzymatic changes in the pancreas. In this model, hemorrhagic pancreatitis developed continuously, and the serum amylase level and activation of zymogen proteases in pancreatic tissue were significantly higher than in cerulein-induced pancreatic tissue 5 h after the first cerulein injection. Furthermore, the effects of cerulein on the serum amylase level and activation of zymogen proteases were dose related. Even 5 micrograms/kg body wt of cerulein, which did not induce any evident edematous change in the pancreas, could activate the zymogen proteases of pancreatic tissue fairly well under water-immersion stress compared with pancreatitis induced by 40 micrograms/kg body wt of cerulein alone. These results indicate that stress accelerates the activation of zymogen proteases induced by cerulein and suggest the possibility that stress may play some role in the development of severe pancreatitis.

Topics: Amylases; Animals; Ceruletide; Dose-Response Relationship, Drug; Edema; Enzyme Precursors; Hemorrhage; Immersion; Male; Necrosis; Pancreatic Elastase; Pancreatitis; Rats; Rats, Inbred Strains; Single-Blind Method; Stress, Physiological; Trypsin; Water

Hypocalcemia and lipid abnormalities commonly occur in acute pancreatitis. Experimentally, increased plasma concentrations of free fatty acids (NEFA) can lower the serum calcium (Ca). We hypothesized that changes in blood-ionized calcium might parallel changes in NEFA concentration in pancreatitis. This hypothesis was tested in a model of severe necrotizing pancreatitis and a model of mild edematous pancreatitis. Adult male Sprague-Dawley rats (300-400 g) were randomized to receive: 100 microL sodium glycodeoxycholic acid (GDOC 34 mmol/L) infused into the pancreatic duct to produce severe necrotizing pancreatitis (Group 1); 100 microL 0.9% NaCl (NS) infused into the pancreatic duct (Group 2); Sham laparotomy (Group 3); A 6 h IV infusion of cerulein (5 mucg/kg/h) to produce mild edematous pancreatitis (Group 4); and a 6 h IV infusion of NS (Group 5). A significant time dependent decrease in blood-ionized Ca concentration, compared to normal rats, was observed in both GDOC-pancreatitis (0.836 +/- .057 vs 1.069 +/- .038 mmol/L p less than 0.001) and cerulein pancreatitis (0.988 +/- .028 vs 1.069 +/- .038 p less than 0.05), which was maximal 24 h after induction of pancreatitis. The degree of hypocalcemia correlated with the severity of pancreatitis (GDOC 0.836 +/- .057 vs cerulein 0.988 +/- .028 p less than .001). Hypocalcemia was not observed in any of the control groups. All experimental and control groups had significantly increased baseline NEFA concentrations compared with normal rats (p less than 0.001); however, no further increase in NEFA concentration occurred in conjunction with the observed time-dependent decline in ionized calcium concentrations. Although the NEFA concentrations observed in these experiments were comparable to those measured in human acute pancreatitis (exclusive of hyperlipemic pancreatitis), the time course of the changes suggests that increases in serum NEFA concentrations in experimental pancreatitis are not the primary factor mediating hypocalcemia.

Topics: Acute Disease; Amylases; Animals; Calcium; Ceruletide; Disease Models, Animal; Edema; Fatty Acids, Nonesterified; Glycodeoxycholic Acid; Hypocalcemia; Male; Pancreatic Ducts; Pancreatitis; Random Allocation; Rats; Rats, Inbred Strains

Pancreatic microvasculature in cerulein-induced pancreatitis was studied at the electron and light microscopic level. Using a modified model of in situ india ink perfusion, focally a marked reduction of the number of india-ink-filled microvessels was found. The numerical density (NA) of filled microvessels was reduced by 66.7% in pancreatitis. The morphological correlate for this extreme numeric reduction might be a collapse of the lumen of pancreatic microvessels. In the presence of cerulein pancreatitis 42% of pancreatic capillaries had a collapsed lumen as shown by electron microscopy. The endothelium of capillaries in acute pancreatitis demonstrated surface blebbing, the formation of cytoplasmatic vacuoles, edema, and swollen mitochondria. Some capillaries had irregularities at the interendothelial junction, and the majority of examined vessels were surrounded by marked perivascular edema. No strict correspondence between histological signs of pancreatitis and light microscopic and/or ultrastructural microvascular alterations could be demonstrated. Our study emphasizes that alterations of microvasculature are present early in experimental edematous pancreatitis. Therefore, alterations of pancreatic microcirculation seem to be of great importance in the pathogenesis of pancreatic inflammation, and should be the subject of further studies.

Topics: Animals; Capillaries; Ceruletide; Edema; Male; Microcirculation; Microscopy, Electron; Pancreatitis; Rats; Rats, Inbred Strains

Previous studies have demonstrated that intravenous catalase infusion protects against the formation of pancreatic edema in cerulein-induced acute pancreatitis; however, polyethylene glycol (PEG)-conjugated catalase given as a bolus was not protective. Using radiolabeled catalase and PEG-catalase in subtherapeutic tracer doses, the pancreas tissue distributions of each were determined in rats with and without pancreatitis. Rats with cerulein-induced pancreatitis developed tissue concentrations of catalase within the pancreas that were three times those of PEG-catalase. The relatively low levels of PEG-catalase in the pancreas outside of the vascular compartment suggest that the failure to prevent edema formation may result from inability of PEG-catalase to reach extravascular sites of injury because of the large molecular size.

Topics: Acute Disease; Animals; Catalase; Ceruletide; Drug Combinations; Edema; Male; Pancreas; Pancreatic Diseases; Pancreatitis; Polyethylene Glycols; Rats; Rats, Inbred Strains

Topics: Acute Disease; Animals; Ceruletide; Edema; Hemorrhage; Magnetic Resonance Spectroscopy; Pancreatitis; Rats; Rats, Inbred Strains; Taurocholic Acid

Topics: Acute Disease; Allopurinol; Animals; Ceruletide; Edema; Esters; Gabexate; Guanidines; Male; Pancreatitis; Rats; Rats, Inbred Strains; Trypsin Inhibitors

Unconscious rats given intravenous ceruletide (diethylamine salt of the decapeptide caerulein) in large pharmacologic doses consistently developed moderate acute pancreatitis by 3 h and florid pancreatitis by 6 h. Biochemical serum markers of acute pancreatitis tended to parallel the severity of the pancreatic damage. In 50% of the rats, mesenteric fat necrosis was present, free peritoneal fluid containing massive elevations of trypsinogen and amylase were noted in most animals. Intravenous secretion at a low dose given simultaneously with ceruletide exerted a variable protective effect on the pathological process. A high dose of secretin produced a striking macroscopic, microscopic, and biochemical protective effect on ceruletide-induced pancreatitis. High resolution light microscopy and electron microscopy showed a marked cellular disorganization in the acini of animals treated with ceruletide alone. By contrast, there was a striking apical redirection of zymogen granules in acini of the animals treated with secretin. The results of this study suggest that high dose intravenous secretin may exert a beneficial effect on acute pancreatitis.

Topics: Acute Disease; Amylases; Animals; Ceruletide; Edema; Fat Necrosis; Lipase; Male; Pancreas; Pancreatitis; Rats; Rats, Inbred Strains; Secretin; Trypsinogen

Conscious rats were infused via a jugular vein catheter with 5 x 10-6 g/kg/h caerulein for periods up to 24 h. On macroscopic inspection a progressive interstitial oedema is seen to develop in the pancreas, from one hour of infusion on and is most marked at twelve hours. This oedema is largely reabsorbed after 24 h treatment, but the pancreas is considerably indurated by this time. Serum amylase levels increase consistently to reach a tenfold elevation above controls after three, six or twelve hours infusion. Premature fusion of condensing vacuoles and secretory granules leads to formation of large vacuoles in the cytoplasm of exocrine pancreatic cells. These vacuoles fuse with the lateral and basal plasma membrane and realease their content into the extracellular space. Regular discharge of zymogen granules at the cell apex into the duct system does not occur. Vacuole formation is associated with cytoplasmic destruction of the pancreatic cells. The rate of protein synthesis decreases consistently as a result of these structural alterations and this change corresponds largely to a reduction of cellular respiration. Release of amylase from isolated pancreatic lobules of caerulein infused animals shows a progressive increase of unstimulated discharge, while in vitro stimulation with 5 x 10-6M carbamylcholine gives secretion patterns of wash-out kinetics. Stimulated discharge of labeled secretory proteins indicates a progressive reduction in the in vitro sensitivity of the pancreatic cells to secretagogues. After 24 h infusion of 5 x 10-6 g/kg/h caerulein the pancreatic lobules are totally insensitive to the in vitro effect of carbamylcholine or caerulein.

Topics: Acute Disease; Amylases; Animals; Carbachol; Ceruletide; Edema; Male; Microscopy, Electron; Pancreas; Pancreatitis; Proteins; Rats; Secretory Rate