endothelin-1 and Pancreatitis

Pancreatic encephalopathy (PE) is a serious complication of severe acute pancreatitis (SAP). In recent years, more and more PE cases have been reported worldwide, and the onset PE in the early stage was regarded as a poor prognosis sign of SAP, but the pathogenesis of PE in SAP still has not been clarified in the past decade. The purpose of this review is to elucidate the possible pathogenesis of PE in SAP.. The English-language literature concerning PE in this review came from the Database of MEDLINE (period of 1991-2005), and the keywords of severe acute pancreatitis and pancreatic encephalopathy were used in the searching.. Many factors were involved in the pathogenesis of PE in SAP. Pancreatin activation, excessive release of cytokines and oxygen free radicals, microcirculation abnormalities of hemodynamic disturbance, ET-1/NO ratio, hypoxemia, bacterial infection, water and electrolyte imbalance, and vitamin B1 deficiency participated in the development of PE in SAP.. The pathogenesis of PE in SAP has not yet been fully understood. The development of PE in SAP may be a multi-factor process. To find out the possible inducing factor is essential to the clinical management of PE in SAP.

Topics: Acute Disease; Animals; Brain Diseases; Cytokines; Endothelin-1; Humans; Hypoxia; Nitric Oxide; Pancreatin; Pancreatitis; Thiamine Deficiency

Topics: Amylases; Animals; Ceruletide; Disease Models, Animal; Endothelin-1; Endothelin-Converting Enzymes; Gene Expression Regulation; Humans; Inflammation; Mice; Oncogenes; Pancreatic Neoplasms; Pancreatitis; Proto-Oncogene Proteins p21(ras); Receptor, Endothelin A; Receptor, Endothelin B

To analyze gene expression profiles in an experimental pancreatitis and provide functional reversal of hypersensitivity with candidate gene endothelin-1 antagonists.. Dibutyltin dichloride (DBTC) is a chemical used as a polyvinyl carbonate stabilizer/catalyzer, biocide in agriculture, antifouling agent in paint and fabric. DBTC induces an acute pancreatitis flare through generation of reactive oxygen species. Lewis-inbred rats received a single i.v. injection with either DBTC or vehicle. Spinal cord and dorsal root ganglia (DRG) were taken at the peak of inflammation and processed for transcriptional profiling with a cDNA microarray biased for rat brain-specific genes. In a second study, groups of animals with DBTC-induced pancreatitis were treated with endothelin (ET) receptor antagonists [ET-A (BQ123) and ET-B BQ788)]. Spontaneous pain related mechanical and thermal hypersensitivity were measured. Immunohistochemical analysis was performed using anti-ET-A and ET-B antibodies on sections from pancreatic tissues and DRG of the T10-12 spinal segments.. Animals developed acute pancreatic inflammation persisting 7-10 d as confirmed by pathological studies (edema in parenchyma, loss of pancreatic architecture and islets, infiltration of inflammatory cells, neutrophil and mononuclear cells, degeneration, vacuolization and necrosis of acinar cells) and the pain-related behaviors (cutaneous secondary mechanical and thermal hypersensitivity). Gene expression profile was different in the spinal cord from animals with pancreatitis compared to the vehicle control group. Over 260 up-regulated and 60 down-regulated unique genes could be classified into 8 functional gene families: circulatory/acute phase/immunomodulatory; extracellular matrix; structural; channel/receptor/transporter; signaling transduction; transcription/translation-related; antioxidants/chaperones/heat shock; pancreatic and other enzymes. ET-1 was among the 52 candidate genes up-regulated greater than 2-fold in animals with pancreatic inflammation and visceral pain-related behavior. Treatments with the ET-A (BQ123) and ET-B (BQ-788) antagonists revealed significant protection against inflammatory pain related mechanical and thermal hypersensitivity behaviors in animals with pancreatitis (P < 0.05). Open field spontaneous behavioral activity (at baseline, day 6 and 30 min after drug treatments (BQ123, BQ788) showed overall stable activity levels indicating that the drugs produced no undesirable effects on normal exploratory behaviors, except for a trend toward reduction of the active time and increase in resting time at the highest dose (300 μmol/L). Immunocytochemical localization revealed that expression of ET-A and ET-B receptors increased in DRG from animals with pancreatitis. Endothelin receptor localization was combined in dual staining with neuronal marker NeuN, and glia marker, glial fibrillary acidic protein. ET-A was expressed in the cell bodies and occasional nuclei of DRG neurons in naïve animals. However, phenotypic expression of ET-A receptor was greatly increased in neurons of all sizes in animals with pancreatitis. Similarly, ET-B receptor was localized in neurons and in the satellite glia, as well as in the Schwann cell glial myelin sheaths surrounding the axons passing through the DRG.. Endothelin-receptor antagonists protect against inflammatory pain responses without interfering with normal exploratory behaviors. Candidate genes can serve as future biomarkers for diagnosis and/or targeted gene therapy.

Topics: Acute Disease; Animals; Disease Models, Animal; Endothelin Receptor Antagonists; Endothelin-1; Gene Expression Profiling; Gene Expression Regulation; Hyperalgesia; Male; Oligopeptides; Organotin Compounds; Pancreas; Pancreatitis; Peptides, Cyclic; Piperidines; Rats; Rats, Inbred Lew; Receptors, Endothelin; Spinal Cord

To explore the protecting effects and mechanisms of dexamethasone on spleen injury in rats with severe acute pancreatitis (SAP).. The rats were randomly divided into a model control group, treated group and sham-operated group. The contents of plasma endotoxin, serum NO, phospholipase A(2) enzyme (PLA(2)) and endothelin-1 (ET-1) were determined. The mortality rate, pathological changes and changes of Bax and Bcl-2 protein expression levels and apoptotic indexes in the spleen of rats were observed in all groups, respectively, at 3, 6 and 12 h after operation.. Although the survival rate was significantly higher in the treated group than in the model control group, there was no significantly different between them (P > 0.05). The expression levels of Bax and Bcl-2 proteins and apoptotic indexes were significantly higher in the treated group than in the model control group at different time points (P < 0.05 or P < 0.01) while other blood indexes contents and pathological severity scores of spleen were significantly lower in the treated group than in the model control group (P < 0.05, P < 0.01 or P < 0.001).. Dexamethasone can protect spleen from injury during SAP mainly by reducing the content of inflammatory mediators in blood.

Topics: Acute Disease; Animals; Anti-Inflammatory Agents; Apoptosis; bcl-2-Associated X Protein; Dexamethasone; Disease Models, Animal; Endothelin-1; Endotoxins; Inflammation Mediators; Male; Nitric Oxide; Pancreatitis; Phospholipases A2; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Severity of Illness Index; Spleen; Splenic Diseases; Taurocholic Acid; Time Factors

Severe acute pancreatitis (SAP) is a commonly seen acute abdominal syndrome characterized by sudden onset, rapid progression and high mortality rate. The damage in peripheral organs may be more severe than that in the pancreas, and can even lead to multiple organ dysfunction. It is critical to recognize early pathological changes in multiple organs. This study aimed to assess the early pathological features of damaged organs in a rat model of SAP.. Thirty clean grade healthy male Sprague-Dawley rats weighing 250-300 g were randomly divided into a model control group (n=15) and a sham-operated group (n=15). The SAP rat model was induced by sodium taurocholate. Samples of blood and from multiple organs were collected 3 hours after operation. We assessed the levels of IL-6, TNF-alpha, PLA2, NO, ET-1, MDA, amylases and endotoxin in blood and observed the early pathological changes in multiple damaged organs.. Levels of IL-6, TNF-alpha, PLA2, NO, ET-1 and MDA in serum and of amylase and endotoxin in plasma of the model control group rats were significantly higher than those of the sham-operated group (P<0.01). Different degrees of pathological change were observed in multiple damaged organs.. Multiple organ injury may occur at the early stage of SAP in rats.

Topics: Acute Disease; Animals; Cytokines; Disease Models, Animal; Edema; Endothelin-1; Hemorrhage; Kidney; Liver; Lung; Male; Malondialdehyde; Necrosis; Nitric Oxide; Pancreas; Pancreatitis; Rats; Rats, Sprague-Dawley

To investigate the effect of baicalin and octreotide on the expression levels of P-selectin protein in multiple organs of rats with severe acute pancreatitis and explore the underlying mechanism.. Rats were randomly divided into sham-operated, model control, baicalin-treated and octreotide-treated groups. At 3, 6 and 12 h after operation, the mortality rates of rats, the contents of plasma endotoxin as well as serum NO and ET-1, the pathological changes in multiple organs, and the expression levels of P-selectin protein in each group were observed.. At 12 h after operation, the mortality rates of rats in treated groups were significantly lower than that in the model control group (P < 0.05), and the pathological severity scores in multiple organs in treated groups were also significantly lower than those in the model control group (P < 0.05). The contents of plasma endotoxin, serum PLA(2) (at 6 and 12 h after operation), ET-1 and NO (at 3 and 12 h after operation) in treated groups were significantly lower than those in the model control group (P < 0.05, P < 0.01 or P < 0.001). In the baicalin-treated group, the expression levels of P-selectin protein in liver (at 3 h after operation), kidney (at 3 and 6 h after operation), pancreas, lung and spleen were significantly lower than those in the model control group (P < 0.01). In the octreotide-treated group, the expression levels of this protein in lung, intestinal mucosa (at 6 and 12 h after operation), lymph nodes (at 3 and 6 h after operation), spleen and thymus were significantly lower than those in the model control group (P < 0.05). Additionally, the products of the staining intensity and positive rate of P-selectin protein in pancreas, spleen (at 3 h after operation), intestinal mucosa (at 6 h after operation), thymus (at 6 h after operation) and lung (at 6 h after operation) in treated groups were significantly lower than those in the model control group (P < 0.05).. Both baicalin and octreotide can exert some protective effects on multiple organs and the former is superior to the latter in protecting pancreas. Furthermore, decreasing the expression levels of P-selectin protein in these organs is one of the possible mechanisms.

Topics: Acute Disease; Animals; Biomarkers; Disease Models, Animal; Endothelin-1; Endotoxins; Flavonoids; Immunohistochemistry; Male; Multiple Organ Failure; Nitric Oxide; Octreotide; P-Selectin; Pancreatitis; Phospholipases A2; Protective Agents; Rats; Rats, Sprague-Dawley; Severity of Illness Index; Taurocholic Acid; Time Factors; Tissue Array Analysis

To study the influence and mechanisms of dexamethasone on mesenteric lymph node of rats with severe acute pancreatitis (SAP).. The SAP rats were assigned to model, treated or sham-operated groups. The mortality, pathological changes of mesenteric lymph nodes, expression levels of NF-kappa B, P-selectin, Bax, Bcl-2 and caspase-3 protein and changes in apoptotic indexes in lymph nodes were observed at 3, 6 and 12 h after operation. The blood levels of endotoxin, superoxide dismutase (SOD), malondialdehyde (MDA), and endothelin-1 (ET-1) in blood were determined.. SOD content, expression of Bax protein and apoptotic index were significantly higher in the treated group than in the model group at different time points (P < 0.05 or P < 0.01). Other blood-detecting indexes and histopathological scores of mesenteric lymph nodes were lower in the treated than in the model group (P < 0.05, P < 0.01 or P < 0.01). NF-kappa B protein expression was negative in all groups. Comparing P-selectin and caspase-3 expression levels among all three groups, there was no marked difference between the model and treated group.. Dexamethasone can protect mesenteric lymph nodes. The mechanism may be by reducing the content of inflammatory mediators in the blood and inducing lymphocyte apoptosis.

Topics: Acute Disease; Animals; Anti-Inflammatory Agents; Apoptosis; bcl-2-Associated X Protein; Caspase 3; Dexamethasone; Disease Models, Animal; Endothelin-1; Lymph Nodes; Male; Malondialdehyde; Mesentery; NF-kappa B; P-Selectin; Pancreatitis; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Severity of Illness Index; Superoxide Dismutase

There is evidence that endothelin (ET) 1 affect neutrophil functions and that patients with severe acute pancreatitis have increased plasma levels of ETs. Under appropriate conditions, neutrophils are able to injure the endothelium. In the present study, we compared healthy donors with acute pancreatitis patients for neutrophil degranulation and its ability to injure the endothelium and the contribution of ET-1 to this injury.. Injury was evaluated by measuring the detachment of endothelial cells (ECV-304) growing in monolayer in coculture with human neutrophils for 4 hours. Neutrophil degranulation was assessed by myeloperoxidase (MPO) activity in coculture supernatants. In some experiments, neutrophils were pretreated with the antagonist of ET(A) receptor (BQ-123, 10(-6) M), which has high affinity for ET-1.. Neutrophils from both healthy donors and acute pancreatitis patients caused detachment of endothelial cells, and levels of MPO activity were increased in coculture supernatants. Neutrophils from acute pancreatitis patients caused significantly higher levels of detachment and MPO in the supernatants. Pretreatment of neutrophils with BQ-123 inhibited the detachment caused by neutrophils from healthy donors but not by neutrophils from acute pancreatitis patients.. These results show that neutrophils taken from healthy donors damage the endothelium by a mechanism dependent on ETs acting via ET(A) receptor, whereas neutrophils from acute pancreatitis patients cause more severe damage that is not dependent on ETs in the in vitro system used.

Topics: Acute Disease; Adult; Antihypertensive Agents; Cell Degranulation; Cells, Cultured; Endothelial Cells; Endothelin A Receptor Antagonists; Endothelin-1; Humans; In Vitro Techniques; Neutrophils; Pancreatitis; Peptides, Cyclic; Peroxidase; Receptor, Endothelin A; Severity of Illness Index

To investigate the changes in plasma endothelin-1 (ET-1) , von Willebrand factor (vWF), serum 6-keto-prostaglandin(1alpha) (PGF(1alpha)) , thromboxane B2 (TXB2), platelet aggregation rate maximum (PAGm) and pancreatic blood flow after reproduction of severe acute pancreatitis (SAP) in rat, and the effect of recombinant staphylokinase (r-Sak) on SAP.. Eighty-one SD rats were divided randomly into the sham-operated group (n=27), the SAP model group (n=27), and the r-Sak treatment group (n=27). SAP was produced by administration of 5% sodium taurocholate into the pancreatic duct. The abdomen of rats was opened at 6, 12 and 18 hours after reproduction of SAP for determining the pancreatic blood flow. Blood was obtained at 6, 12 and 18 hours after reproduction of SAP for determining the concentration of plasma vWF with enzyme-labeled immunosorbent assay (ELISA). The concentration of plasma ET-1 and serum 6-keto-PGF(1alpha), and TXB2 were detected by radioimmunoassay. The PAGm induced by collagen and eicosanoids was assessed.. Pancreatic blood flow in the SAP group appeared to have a decreasing trend at 6,12 and 18 hours after operation and were significantly decreased at all time points after reproduction of the model, compared with those of the sham-operated group (all P<0.05). The PAGm, content of plasma ET-1, vWF, and TXB2 were significantly increased at all time points after reproduction of the model, while 6-keto-PGF(1alpha) was significantly decreased, compared with those of the sham-operated group (all P < 0.05). Compared with SAP model group, PAGm, the content of plasma ET-1, vWF, and serum TXB2 in the r-Sak group were decreased at all time points, however, the content of serum 6-keto-PGF(1alpha) was increased (all P<0.05).. The r-Sak can improve pancreatic microcirculation and enhance pancreatic blood flow in rats with SAP, and may be beneficial in the treatment of SAP.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Disease Models, Animal; Endothelin-1; Ischemia; Metalloendopeptidases; Pancreas; Pancreatitis; Platelet Aggregation; Random Allocation; Rats; Rats, Sprague-Dawley; Regional Blood Flow; Thromboxane B2; von Willebrand Factor

To establish an ideal model of multiple organ injury of rats with severe acute pancreatitis (SAP).. SAP models were induced by retrograde injection of 0.1 mL/100 g 3.5% sodium taurocholate into the biliopancreatic duct of Sprague-Dawley rats. The plasma and samples of multiple organ tissues of rats were collected at 3, 6 and 12 h after modeling. The ascites volume, ascites/body weight ratio, and contents of amylase, endotoxin, endothelin-1 (ET-1), nitrogen monoxidum (NO), phospholipase A(2) (PLA(2)), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) in plasma were determined. The histological changes of multiple organs were observed under light microscope.. The ascites volume, ascites/body weight ratio, and contents of various inflammatory mediators in blood were higher in the model group than in the sham operation group at all time points [2.38 (1.10), 2.58 (0.70), 2.54 (0.71) vs 0.20 (0.04), 0.30 (0.30), 0.22 (0.10) at 3, 6 and 12 h in ascites/body weight ratio; 1582 (284), 1769 (362), 1618 (302) (U/L) vs 5303 (1373), 6276 (1029), 7538 (2934) (U/L) at 3, 6 and 12 h in Amylase; 0.016 (0.005), 0.016 (0.010), 0.014 (0.015) (EU/mL) vs 0.053 (0.029), 0.059 (0.037), 0.060 (0.022) (EU/mL) at 3, 6 and 12 h in Endotoxin; 3.900 (3.200), 4.000 (1.700), 5.300 (3.000) (ng/L) vs 41.438 (37.721), 92.151 (23.119), 65.016 (26.806) (ng/L) at 3, 6 and 12 h in TNF-alpha, all P < 0.01]. Visible congestion, edema and lamellar necrosis and massive leukocytic infiltration were found in the pancreas of rats of model group. There were also pathological changes of lung, liver, kidney, spleen, ileum, lymphonode, thymus, myocardium and brain.. This rat model features reliability, convenience and a high achievement ratio. Complicated with multiple organ injury, it is an ideal animal model of SAP.

Topics: Acute Disease; Amylases; Animals; Ascitic Fluid; Body Weight; Brain; Disease Models, Animal; Endothelin-1; Endotoxins; Feasibility Studies; Ileum; Interleukin-6; Kidney; Liver; Lymph Nodes; Male; Multiple Organ Failure; Myocardium; Nitric Oxide; Pancreas; Pancreatitis; Phospholipases A; Rats; Rats, Sprague-Dawley; Reproducibility of Results; Severity of Illness Index; Taurocholic Acid; Thymus Gland; Time Factors; Tumor Necrosis Factor-alpha

To investigate the protective effects and mechanisms of Baicalin and octreotide on renal injury of rats with severe acute pancreatitis (SAP).. One hundred and eighty SD rats were randomly assigned to the model group, Baicalin-treated group, octreotide-treated group and sham operation group. The mortality, plasma endotoxin level, contents of blood urea nitrogen (BUN), creatinine (CREA), phospholipase A2 (PLA2), nitrogen monoxide (NO), tumor necrosis factor (TNF)-alpha, IL-6 and endothelin-1 (ET-1) in serum, expression levels of renal Bax and Bcl-2 protein, apoptotic indexes and pathological changes of kidney were observed at 3, 6 and 12 h after operation.. The renal pathological changes were milder in treated group than in model group. The survival at 12 h and renal apoptotic indexes at 6 h were significantly (P<0.05) higher in treated group than in model group [66.67% vs 100%; 0.00 (0.02)% and 0.00 (0.04)% vs 0.00 (0.00)%, respectively]. The serum CREA content was markedly lower in octreotide-treated group than in model group at 3 h and 6 h (P<0.01, 29.200+/-5.710 micromol/L vs 38.400+/-11.344 micromol/L; P<0.05, 33.533+/-10.106 micromol/L vs 45.154+/-17.435 micromol/L, respectively). The expression level of renal Bax protein was not significantly different between model group and treated groups at all time points. The expression level of renal Bcl-2 protein was lower in Baicalin-treated group than in model group at 6 h [P<0.001, 0.00 (0.00) grade score vs 3.00 (3.00) grade score]. The Bcl-2 expression level was lower in octreotide-treated group than in model group at 6 h and 12 h [P<0.05, 0.00 (0.00) grade score vs 3.00 (3.00) grade score; 0.00 (0.00) grade score vs 0.00 (1.25) grade score, respectively]. The serum NO contents were lower in treated groups than in model group at 3 h and 12 h [P<0.05, 57.50 (22.50) and 52.50 (15.00) micromol/L vs 65.00 (7.50) micromol/L; P<0.01, 57.50 (27.50) and 45.00 (12.50) micromol/L vs 74.10 (26.15) micromol/L, respectively]. The plasma endotoxin content and serum BUN content (at 6 h and 12 h) were lower in treated groups than in model group. The contents of IL-6, ET-1, TNF-alpha (at 6 h) and PLA2 (at 6 h and 12 h) were lower in treated groups than in model group [P<0.001, 3.031 (0.870) and 2.646 (1.373) pg/mL vs 5.437 (1.025) pg/mL; 2.882 (1.392) and 3.076 (1.205) pg/mL vs 6.817 (0.810) pg/mL; 2.832 (0.597) and 2.462 (1.353) pg/mL vs 5.356 (0.747) pg/mL; 16.226 (3.174) and 14.855 (5.747) pg/mL vs 25.625 (7.973) pg/mL; 18.625 (5.780) and 15.185 (1.761) pg/mL vs 24.725 (3.759) pg/mL; 65.10 (27.51) and 47.60 (16.50) pg/mL vs 92.15 (23.12) pg/mL; 67.91+/-20.61 and 66.86+/-22.10 U/mL, 63.13+/-26.31 and 53.63+/-12.28 U/mL vs 101.46+/-14.67 and 105.33+/-18.10 U/mL, respectively].. Both Baicalin and octreotide can protect the kidney of rats with severe acute pancreatitis. The therapeutic mechanisms of Baicalin and octreotide might be related to their inhibition of inflammatory mediators and induction of apoptosis. Baicalin might be a promising therapeutic tool for severe acute pancreatitis.

Topics: Acute Disease; Animals; Anti-Infective Agents; Apoptosis; bcl-2-Associated X Protein; Creatinine; Dose-Response Relationship, Drug; Endothelin-1; Flavonoids; Gastrointestinal Agents; Interleukin-6; Kidney Diseases; Kidney Tubules; Male; Nitric Oxide; Octreotide; Pancreatitis; Phospholipases A2; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Tumor Necrosis Factor-alpha

Alleviation of microcirculation disorders in severe acute pancreatitis (SAP) can improve survival rates, and low molecular weight heparin (LMWH) is well known to have potent ameliorative effect on microcirculation disorders caused by anti-coagulant activity. The aim of this study was to investigate the effects of LMWH on pancreatic microcirculation in SAP in rats.. SD rats were randomly divided into 3 groups: sham operation (S) group, SAP group, and LMWH treatment (LT) group. The concentrations of serum amylase, tumor necrosis factor-alpha (TNF-alpha), endothelin-1 (ET-1), pancreatic ultrastructure were examined at 24 hours after the models were set up in each group.. Compared with S group, the concentration of serum amylase, ET-1, and TNF-alpha in SAP group were significantly increased (P < 0.001); After LMWH treatment, the concentration of serum amylase, ET-1, TNF-alpha were decreased significantly compared with SAP group (P < 0.001, 0.01, 0.001, respectively). On electron microscopy, the microthrombosis in LT group was significantly less than that in SAP group. The 3-day survival rate in SAP group (25.0%) was significantly lower than that in S group (100.0%, P < 0.05) and in LT group (87.5%, P < 0.05).. The disorder of pancreatic microcirculation may be involved in the inflammatory response of rats with SAP. LMWH can effectively improve the survival rate of SAP, and alleviate the severity of microcirculation disorders through its antithrombin effects and down-regulate the levels of serum ET-1 and TNF-alpha.

Topics: Acute Disease; Animals; Anticoagulants; Disease Models, Animal; Endothelin-1; Heparin, Low-Molecular-Weight; Microcirculation; Microscopy, Electron; Pancreas; Pancreatitis; Rats; Rats, Sprague-Dawley; Survival Rate; Tumor Necrosis Factor-alpha

Ischaemia-reperfusion (IR)-associated microcirculatory changes play a major role in acute post-transplantation pancreatitis. The pathophysiological role of platelets in these events is unknown. The aim of this study was to examine platelet adhesion and function during early reperfusion after pancreatic ischaemia.. Rats were subjected to warm pancreatic ischaemia by cross-clamping of the pancreatic vessels for 1 h. After 1 h of reperfusion, platelet-endothelium interaction was evaluated after platelet separation and staining by fluorescence microscopy. Amylase levels and pancreatic histology were evaluated 24 h after reperfusion. Animals treated according to an identical protocol, but without ischaemia, served as controls.. Mild pancreatitis had developed by 24 h after IR; serum amylase levels were significantly higher than those in control animals. The numbers of adherent platelets in capillaries and venules were significantly increased, and platelet velocity in capillaries was significantly decreased, in the IR group compared with controls. There was significantly more oedema and inflammation in pancreatic tissue after IR.. Warm ischaemia for 1 h followed by reperfusion for 24 h caused mild pancreatitis in this experimental model. The pancreatic microcirculation was characterized by pronounced platelet-endothelium interaction in capillaries and venules. These results suggest that platelet activation may play an important role in acute post-transplantation pancreatitis.

Topics: Acute Disease; Animals; Blood Platelets; Constriction; Endothelin-1; Male; Pancreas; Pancreatitis; Platelet Adhesiveness; Rats; Rats, Wistar; Reperfusion Injury; Thromboxane A2

To assess effects of NF-kappaB activation inhibitor (pyrrolidine dithiocarbamate--PDTC) alone or with endothelins (ET-1, ET-2, ET-3) in early course of cerulein-induced acute pancreatitis (AP) in rats.. After 4 h of AP in Wistar rats, treated with PDTC 10 or 40 mg/kg or with PDTC 10 mg/kg and ET-1, ET-2 or ET-3, 0.5 or 1.0 nmol/kg twice i.p. in 1 h interval, free active trypsin (FAT), total potential trypsin (TPT) and lipase in 12000 x g supernatants of pancreatic homogenates, plasma alpha-amylase and histological changes were assayed. %FAT/TPT was an index of trypsinogen activation.. %FAT/TPT significantly increased to 12.42 +/- 2.14%, lipase to 5.51 +/- 0.84 U/mg protein and alpha-amylase to 28.5 +/- 5.61 U/mL in AP vs 1.96 +/- 0.31%, 1.29 +/- 0.11 U/mg and 5.80 +/- 1.38 U/ml in healthy control. Higher dose PDTC attenuated trypsinogen activation to 3.01 +/- 0.53% and alpha-amylase to 15.3 +/- 1.38. PDTC and ET-1 attenuated %FAT/TPT to 2.55 +/- 0.18% with lower and 2.34 +/- 0.44% with higher dose. ET-3 was less effective than ET-1: 6.76 +/- 0.46% with lower dose. Lower doses of ET-1 and ET-2 with PDTC, diminished lipase activity to 2.60 +/- 0.36 and 2.94 +/- 0.33.. Cumulative attenuation of trypsinogen activation after lower dose of PDTC and ET-1 approximated the effect of higher dose of PDTC. Additional effect of ET-3 was weaker than ET-1, and ET-2 was ineffective in this respect. The combination of this NF-kappaB activation inhibitor and ET-1 could be beneficial in early course of edematous AP by attenuating of trypsinogen activation. However, it should be treated with caution because of some unfavorable effects on histological scores of pancreatic injury.

Topics: Acute Disease; alpha-Amylases; Animals; Antioxidants; Ceruletide; Endothelin-1; Endothelin-2; Endothelin-3; Enzyme Activation; Lipase; Male; NF-kappa B; Pancreatitis; Pyrrolidines; Rats; Rats, Wistar; Thiocarbamates; Trypsinogen

To assess the effect of endothelins: ET-1, ET-2 and ET-3 on trypsinogen activation, lipase activity and histological changes in the pancreas in early (4 hrs) cerulein acute pancreatitis (AP) in rats.. In 45 Wistar rats with cerulein induced AP (2 x 40 microg/kg i.p. at 1 hour interval, the effect of endothelins at the dose 2 x 0.5 or 2 x 1.0 nmol/kg i.p. was assessed vs untreated AP; 6 healthy rats were control (C). Free active trypsin (FAT), total potential trypsin after activation with enterokinase (TPT), lipase in 12000 xg supernatants of pancreatic homogenates and the plasma alpha-amylase were assayed. The %FAT/TPT was an index of trypsinogen activation.. %FAT/TPT increased from 3.0 +/- 0.6 in C to 16.2 +/- 3.1 in AP (p < 0.01). ET-1 decreased this index to 4.8 +/- 1.1 after higher dose (p < 0.01); the effect of lower dose was insignificant. Attenuating effect of ET-2 was significant: 7.3 +/- 1.7 after higher dose (p < 0.05) and 6.1 +/- 0.9 after lower dose (p < 0.01). ET-3 diminished this index to 4.5 +/- 1.5 (p < 0.01) and to 6.3 +/- 2.2 (p < 0.05) respectively. Lipase activity in supernatant increased from 4.1 +/- 0.6 in C to 6.3 +/- 0.7 U/mg protein in untreated AP (p < 0.05) and plasma alpha-amylase from 7.0 +/- 0.6 in C to 25.9 +/- 4.3 U/ml in AP (p < 0.001), without essential changes in treated groups vs untreated AP. Higher doses of endothelins decreased inflammatory cell infiltration score in AP.. The exogenous endothelins, especially ET-2 and ET-3 and to lesser extent ET-1 exerted some protective effect in early, edematous acute pancreatitis by the attenuation of trypsinogen activation and inflammatory cell infiltration in the pancreas.

Topics: Acute Disease; alpha-Amylases; Animals; Ceruletide; Endothelin-1; Endothelin-2; Endothelin-3; Endothelins; Enzyme Activation; Lipase; Male; Pancreatitis; Rats; Rats, Wistar; Time Factors; Trypsinogen

The role of endothelin-1 (ET-1) and of its receptor A (ETA) blockade in oedematous acute pancreatitis (AP) remains unclear. In 40 male Wistar rats with i.p. cerulein-induced AP, lasting 4 hours, ET-1 2x0.5 nmol/kg and 2x1.0 nmol/kg or selective ETA antagonist LU 302146, 10 mg/kg and 20 mg/kg was given i.p. simultaneously with cerulein. Histological and ultrastructural studies of pancreatic specimens were done. ET-1 decreased the inflammatory infiltration, but not the mean scores of necrosis and vacuolization in AP. The ultrastructural damage of acinar cells was less evident after ET-1 than in untreated AP. Selective ETA antagonist slightly aggravated the vacuolization and necrosis of acinar cells and some ultrastructural alterations in AP. In conclusion, ET-1, in contrast to selective ETA antagonist, exerts some protective effect in the early course of oedematous cerulein-induced acute pancreatitis in rats.

Topics: Acute Disease; Animals; Cytoplasmic Granules; Endothelin-1; Male; Pancreas; Pancreatitis; Rats; Rats, Wistar; Receptor, Endothelin A; Vacuoles

Severe acute pancreatitis is occasionally associated with pancreatic and intestinal necrosis. Mesenteric vasoconstriction is one of the most probable types of pathogenesis of these complications.. To investigate the involvement of endothelin-1 (ET-1), a potent vasoconstrictor.. Plasma ET-1 concentrations were extremely high in patients with pancreatic and/or diffuse intestinal necrosis. ET-1 mRNA was demonstrated in the rat pancreas, and the production of ET-1 protein by human umbilical vein endothelial cells was enhanced by tumor necrosis factor-alpha, thrombin, and protease-activated receptor-2-activating peptide. Administration of ET-1 in vivo induced mesenteric arterial spasm and decreased pancreatic and intestinal blood flow.. These results suggest the following: ET-1 is produced in and around the pancreas, mainly by endothelial cells, in severe acute pancreatitis; in the inflammatory setting, cytokines, activated thrombin and trypsin, may stimulate ET-1 production in a paracrine fashion; produced ET-1 may exaggerate the splanchnic microcirculation; and progressive ischemia may lead to necrosis of the pancreas and intestine.

Topics: Acute Disease; Adolescent; Adult; Aged; Animals; Endothelin-1; Female; Humans; Intestines; Ischemia; Male; Mesenteric Arteries; Middle Aged; Necrosis; Pancreas; Pancreatitis; Rats; Rats, Wistar; RNA, Messenger; Vasoconstriction

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

Capillary leakage with fluid loss into the third space contributes to many of the early systemic complications in severe acute pancreatitis. There has been increasing interest in endothelin as one of the factors affecting capillary permeability.. To elucidate further the role of endothelin in the development of capillary leakage in acute pancreatitis by investigating the effect of exogenous endothelin administration and endothelin receptor blockade in sham operated animals and two models of acute pancreatitis.. Determination of capillary permeability in the pancreas and colonic mucosa by quantifying extravasation of fluorescein labelled dextran using a novel computer assisted video image analysis system.. Pancreatic and colonic capillary permeability increased stepwise from mild to severe acute pancreatitis. Endothelin increased pancreatic and colonic capillary permeability in healthy animals and animals with mild acute pancreatitis but had no additional adverse effect in severe acute pancreatitis. Endothelin receptor blockade decreased pancreatic capillary permeability in sham operated rats but had no effect on the colon. In mild and severe acute pancreatitis, endothelin receptor blockade stabilised increased capillary permeability in both the pancreas and colon.. Endothelin plays an important role in mediating capillary permeability in the pancreas. In severe pancreatitis, it increases capillary permeability even outside the pancreas, thereby contributing to capillary leakage. Endothelin receptor blockade significantly reduces capillary permeability in acute pancreatitis both in and outside the pancreas, suggesting a therapeutic approach to counteract capillary leakage in severe acute pancreatitis.

Topics: Animals; Capillary Leak Syndrome; Capillary Permeability; Endothelin Receptor Antagonists; Endothelin-1; Male; Pancreatitis; Rats; Rats, Sprague-Dawley; Receptors, Endothelin

We studied whether gastrointestinal transit was disturbed during acute pancreatitis and attempted to identify which mechanisms might be involved in acute pancreatitis. Using a noninvasive hydrogen breath test to determine the orocecal transit time, 24 patients with the clinical diagnosis of acute pancreatitis were enrolled into the intestinal motility study. Orocecal transit time was measured twice in all patients: once at the acute stage and once at recovery. Blood was obtained to study amylase, lipase, C-reactive protein, erythrocyte sedimentation rate, and endothelin-1 and nitrate/nitrite levels. Orocecal transit times measured at the acute stage were significantly delayed compared with those at recovery (mean values +/- SEM, 130.0 +/- 9.0 vs 80.8 +/- 7.4 min, P < 0.001). Plasma endothelin-1 levels exhibited a positive correlation with orocecal transit times in the acute stage (r = 0.509, P = 0.011). The percentages of altered orocecal transit times also correlated with the percentages of altered plasma endothelin-1 levels (r = 0.751, P < 0.001). Plasma nitrate/nitrite levels significantly decreased at the acute stage compared with those at recovery (5.25 +/- 0.82 vs 10.20 +/- 1.24 microM, P < 0.05). We conclude that intestinal transit is delayed in patients with mild to moderate acute pancreatitis. Elevated plasma endothelin-1 levels in the acute stage may be one mechanism mediating intestinal dysmotility.

Topics: Acute Disease; Endothelin-1; Female; Gastrointestinal Motility; Gastrointestinal Transit; Humans; Male; Middle Aged; Pancreatitis

Using in vivo microscopy red blood cell (RBC) velocities, functional capillary density (FCD) and capillary diameters were estimated after inducing acute pancreatitis by intraductal infusion of sodium taurocholate (0.8 ml; 4%) or after topical superfusion of the pancreas with ET-1 (100 pmol). Sodium taurocholate mediated a significant decrease in RBC velocities between 50 and 70%, transient decrease in capillary diameters by 10%, and a sustained decrease in FCD between 60 and 70% paralleled by a dramatic heterogeneity in blood flow. Topical superfusion of the exteriorized pancreas with ET-1 caused a significant decrease in RBC velocities between 65 and 75%, a sustained decrease in capillary diameters by 10%, and a decrease in FCD by 45% accompanied by an increase in flow heterogeneity. Following sodium taurocholate infusion pancreas histology revealed a severe edema and sublobular acinar cell necrosis, while topical ET-1 application displayed a severe edema of the pancreas with focal acinar cell necrosis. Thus, ET-1 mediated a deterioration of the pancreatic microcirculation, which is similar to the microcirculatory failure found in sodium taurocholate-induced experimental pancreatitis and was associated with focal acinar cell necrosis. We are thus inclined to hypothesize that endothelin released by injured endothelial cells during acute biliary pancreatitis promotes microcirculatory failure and ischemia in acute pancreatitis, eventually leading to acinar cell necrosis.

Topics: Acute Disease; Administration, Topical; Animals; Blood Flow Velocity; Capillaries; Endothelin-1; Male; Microcirculation; Pancreas; Pancreatitis; Rats; Rats, Inbred Lew; Regional Blood Flow; Taurocholic Acid

We have reported previously that cerulein-induced edematous pancreatitis would transform into hemorrhagic pancreatitis by administration of endothelin-1 in rats. In the present study, we tried to protect rat model from developing into hemorrhagic pancreatitis with BQ123 (an ETA receptor antagonist).. The rat model was made by 5-hour restraint water-immersion stress and two intraperitoneal injections of cerulein (40 micrograms/kg) at hourly interval. BQ123 (3 or 6 mg/kg) was administered intravenously 30 minutes before and 2 hours after the first cerulein injection.. Acute hemorrhagic pancreatitis was induced in all rats treated with cerulin + stress. The score for pancreatic hemorrhage was 2.4 +/- 0.2 in this group. In the rats pretreated with BQ123, the score was reduced to 1.0 +/- 0.0, pancreas wet weight and serum amylase activity were significantly reduced, and histologic alterations in the pancreas lightened, also the local pancreatic blood flow improved without affecting the systemic blood pressure.. These results suggest that endothelin-1 should play a role in aggravating the development of acute hemorrhagic pancreatitis, through its action on the pancreatic microcirculation.

Topics: Acute Disease; Animals; Ceruletide; Endothelin Receptor Antagonists; Endothelin-1; Male; Pancreatitis; Peptides, Cyclic; Rats; Rats, Sprague-Dawley

Chronic pancreatitis (CP) is characterized by the presence of an inflammatory infiltrate with progressive destruction of acinar cells and fibrosis. The finding that endothelin-1 (ET-1), an endothelium-derived peptide having vasoconstrictive and mitogenic properties, reduces pancreatic blood flow (PBF) in normal rats suggested that the peptide may be associated with the reduced PBF seen in animal models of CP and with the morphological abnormalities of the disease. This study investigates changes in blood flow to the pancreas and other abdominal organs in a rat model of CP and compares ET-1 production in the pancreata of these rats and normal controls. CP was induced in male Wistar rats by the injection of oleic acid into the common bile/pancreatic duct. The radiolabeled microsphere technique was employed to measure blood flow to the pancreas, duodenum, liver, spleen, and kidneys. Immunohistochemistry was used to investigate the cellular production of ET-1. After 3 weeks, significant decreases were noted in body weight, pancreatic weight, and pancreatic DNA, amylase, and protein content in the animals with CP. PBF was reduced by 64% and duodenal blood flow by 80% relative to those in control animals. Hepatic and splenic blood flows were increased by 91 and 88%, respectively, compared to those in controls. A 50% decrease in renal blood flows were increased by 91 and 88%, respectively, compared to those in controls. A 50% decrease in renal blood flow was also seen in the experimental group after 3 weeks. Pancreata from animals with CP stained diffusely for ET-1 in the cytoplasm of vascular endothelial, acinar, and ductal cells. In the control pancreata, focal staining for ET-1 was observed only in acinar cells. This difference was significant in endothelial and ductal cells. There was weak staining of islet cells in both groups. The results suggest that elevation in local production of ET-1 may be associated with the morphological and hemodynamic changes of CP.

Topics: Animals; Blood Flow Velocity; Chronic Disease; Disease Models, Animal; Endothelin-1; Immunohistochemistry; Male; Microcirculation; Microspheres; Pancreas; Pancreatitis; Rats; Rats, Wistar; Regional Blood Flow