Endothelin receptor blockade in severe acute pancreatitis leads to systemic enhancement of microcirculation, stabilization of capillary permeability, and improved survival rates

Treatment of Microcirculatory Disturbances in Acute Pancreatitis: Where Are We Now?

Acute pancreatitis is a serious inflammatory condition. Research has shown an increase in the number of pancreatitis-associated hospitalizations, with a marked decline in the mortality rates down to 0.79% in patients with acute pancreatitis and 0.26% in patients with exacerbation of chronic pancreatitis. Up to one-third of patients develop pancreatic tissue necrosis, with a mortality rate of 30%. One of the mechanisms is the disturbances in pancreatic microcirculation due to the release of endothelin, a long-acting vasoconstrictor. The development of pancreatitis causes the release of other inflammatory mediators, which reduce blood flow in the microcirculation. The activation of intracellular trypsinogen initiates a cascade of mechanisms in pancreatitis. There is no specific treatment for acute pancreatitis. Protease inhibitors are not effective in treating severe acute pancreatitis. There is an important role of low-molecular-weight heparin in attenuating necrosis and restoring perfusion of the pancreas. Other drugs used are endothelin receptor antagonists, antagonist of interleukin-1 and interleukin-6 receptors, α-tocopherol, tumor necrosis factor-α and platelet-activating factor inhibitors, acetylsalicylic acid, and local intra-arterial injection of lidocaine. The prophylactic use of antibiotics is not recommended. The treatment outcome of acute pancreatitis is still unsatisfactory.

Effect of Early Continuous Veno-Venous Haemofiltration in Severe Acute Pancreatitis for the Prevention of Local Pancreatic Complications

Objective

To compare the conventional treatment and continuous veno-venous haemofiltration (CVVH) in severe acute pancreatitis (SAP) for the prevention of pseudocyst and walled-off necrosis. Patients and Methods. Forty-two patients were divided into two treatment groups: conventional treatment group contained 24 patients and CVVH had 18. Conventional treatment group patients were treated symptomatically and according to the causes. CVVH group patients were treated symptomatically, and CVVH was done within 2 hours of admission.

Results

In both groups, there was a decrease in amylase, lipase, CRP, IL-6, IL-10, TNF-alpha, Ranson score, Balthazar score, and APACHE-II score after 72 hours, but the decrease was significantly greater in CVVH patients. There were no any local pancreatic complications in CVVH patients, but 1 patient had an acute peripancreatic fluid collection, 2 patients had pseudocyst, and 2 patients had walled-off necrosis (WON), and a mortality one was seen in the conventional treatment group.

Conclusion

The present study shows that early CVVH may be able to prevent the formation of pseudocyst and win in SAP patients.

Comprehensive Mechanism, Novel Markers and Multidisciplinary Treatment of Severe Acute Pancreatitis-Associated Cardiac Injury - A Narrative Review

Acute pancreatitis (AP) is one of the common acute abdominal inflammatory diseases in clinic with acute onset and rapid progress. About 20% of the patients will eventually develop into severe acute pancreatitis (SAP) characterized by a large number of inflammatory cells infiltration, gland flocculus flaky necrosis and hemorrhage, finally inducing systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS). Pancreatic enzyme activation, intestinal endotoxemia (IETM), cytokine activation, microcirculation disturbance, autonomic nerve dysfunction and autophagy dysregulation all play an essential role in the occurrence and progression of SAP. Organ dysfunction is the main cause of early death in SAP. Acute kidney injury (AKI) and acute lung injury (ALI) are common, while cardiac injury (CI) is not, but the case fatality risk is high. Many basic studies have observed obvious ultrastructure change of heart in SAP, including myocardial edema, cardiac hypertrophy, myocardial interstitial collagen deposition. Moreover, in clinical practice, patients with SAP often presented various abnormal electrocardiogram (ECG) and cardiac function. Cases complicated with acute myocardial infarction and pericardial tamponade have also been reported and even result in stress cardiomyopathy. Due to the molecular mechanisms underlying SAP-associated cardiac injury (SACI) remain poorly understood, and there is no complete, unified treatment and sovereign remedy at present, this article reviews reports referring to the pathogenesis, potential markers and treatment methods of SACI in recent years, in order to improve the understanding of cardiac injury in severe pancreatitis.

Current status of diagnosis and Mesenchymal stem cells therapy for acute pancreatitis

Acute pancreatitis (AP) is an acute gastrointestinal disorder that is the most common and requiring emergency hospitalization. Its incidence is increasing worldwide, thus increasing the burden of medical services. Approximately 20% of the patients develop moderate to severe necrotizing pancreatitis associated with pancreatic or peri-pancreatic tissue necrosis and multiple organ failure. There are many reports about the anti-inflammatory effect of mesenchymal stem cells (MSCs) on pancreatitis and the repair of tissue damage. MSCs cells come from a wide range of sources, autologous MSCs come from bone marrow and allogeneic MSCs such as umbilical cord blood MSCs, placenta-derived MSCs, etc. The wide source is not only an advantage of MSCs but also a disadvantage of MSCs. Because of different cell sources and different methods of collection and preparation, it is impossible to establish a unified standard method for evaluation of efficacy. The biggest advantage of iMSCs is that it can be prepared by a standardized process, and can be prepared on a large scale, which makes it easier to commercialize. This paper reviews the present status of diagnosis and progress of MSCs therapy for AP.

Effects of ω-3 Fatty Acids on Toll-like Receptor 4 and Nuclear Factor κB p56 in the Pancreas of Rats With Severe Acute Pancreatitis

OBJECTIVES

The aims of this study were to determine the effects of ω-3 fatty acids (ω-3FAs) on the Toll-like receptor 4 (TLR4)/nuclear factor κB p56 (NF-κBp56) signaling pathway in the pancreas of rats with severe acute pancreatitis (SAP).

METHODS

Sixty-four Sprague-Dawley rats were randomly divided into 4 groups: the control, SAP-saline, SAP-soybean oil, and SAP-ω-FA groups. Severe acute pancreatitis was induced by the retrograde infusion of sodium taurocholate into the pancreatic duct. The expression of TLR4 and NF-κBp56 in the pancreas was evaluated by immunohistochemistry and Western blot analysis. The levels of the proinflammatory cytokines interleukin 6 and tumor necrosis factor α in the pancreas were measured by enzyme-linked immunosorbent assays.

RESULTS

Toll-like receptor 4, NF-κBp56, and inflammatory cytokine expression in the pancreas was increased significantly in the SAP group compared with that in the control group (P < 0.05), but was significantly decreased in the ω-3FA group compared with that in the soybean oil group at 24 and 48 hours (P < 0.05).

CONCLUSIONS

Our results suggest that during the initial stage of SAP ω-3FAs could efficiently lower the inflammatory response by activating the TLR4/NF-κBp56 signaling pathway.

Endothelial markers are associated with pancreatic necrosis and overall prognosis in acute pancreatitis: A preliminary cohort study

BACKGROUND

Endothelial injury is believed to play an important role in the evolution of pancreatic microcirculatory dysfunction and pancreatic necrosis (PN) in patients with acute pancreatitis (AP). The aim of this study was to investigate the role of three endothelial markers (von Willebrand factor, vWF; E-selectin; endothelial protein C receptor, EPCR) in the early phase of AP, especially the relationship between endothelial markers and PN.

METHODS

From March 2015 to March 2016, 57 AP patients admitted within 72 h of symptom onset in our hospital were included for this study. Blood samples were taken on admission and the clinical characteristics and outcomes of these patients were recorded. The levels of vWF, E-selectin and EPCR were measured using ELISA for analysis and compared with other severity markers of AP.

RESULTS

All the three markers were significantly different in healthy control, mild, moderate and severe AP patients. Moreover, the endothelial markers, especially vWF, also showed significant difference in patients with different extent of PN, as well as those with or without MODS. Additionally, the levels of endothelial markers correlated well with other commonly used markers of AP severity.

CONCLUSION

Elevated endothelium-related mediators (vWF, E-selectin and EPCR) appear to participate in the development of PN and may be a potential indicator of overall prognosis. Our results may help clinicians better understand the pathophysiological process of the development of PN.

Pathophysiological mechanisms in acute pancreatitis: Current understanding

The precise mechanisms involved in the pathophysiology of acute pancreatitis (AP) are still far from clear. Several earlier studies have focused mainly on pancreatic enzyme activation as the key intracellular perturbation in the pancreatic acinar cells. For decades, the trypsin-centered hypothesis has remained the focus of the intra-acinar events in acute pancreatitis. Recent advances in basic science research have lead to the better understanding of various other mechanisms such as oxidative and endoplasmic stress, impaired autophagy, mitochondrial dysfunction, etc. in causing acinar cell injury. Despite all efforts, the clinical outcome of patients with AP has not changed significantly over the years. This suggests that the knowledge of the critical molecular pathways in the pathophysiology of AP is still limited. The mechanisms through which the acinar cell injury leads to local and systemic inflammation are not well understood. The role of inflammatory markers and immune system activation is an area of much relevance from the point of view of finding a target for therapeutic intervention. Some data are available from experimental animal models but not much is known in human pancreatitis. This review intends to highlight the current understanding in this area.

Treating acute pancreatitis: what's new?

The medical treatment of acute pancreatitis continues to focus on supportive care, including fluid therapy, nutrition, and antibiotics, all of which will be critically reviewed. Pharmacologic agents that were previously studied were found to be ineffective likely due to a combination of their targets and flaws in trial design. Potential future pharmacologic agents, particularly those that target intracellular calcium signaling, as well as considerations for trial design will be discussed. As the incidence of acute pancreatitis continues to increase, greater efforts will be needed to prevent hospitalization, readmission and excessive imaging in order to reduce overall healthcare costs. Primary prevention continues to focus on post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis and secondary prevention on cholecystectomy for biliary pancreatitis as well as alcohol and smoking abstinence.

Protective effect of Lai Fu Cheng Qi decoction on severe acute pancreatitis-induced myocardial injury in a rat model

The aim of the present study was to evaluate the effects of Lai Fu Cheng Qi decoction on myocardial injury in rats with severe acute pancreatitis (SAP). In total, 30 rats were randomly divided into sham, SAP and decoction treatment groups. SAP was induced by a retrograde pancreatic duct injection of 5% sodium taurocholate in the SAP and decoction treatment groups. Rats in decoction treatment group also received intragastric administration of Lai Fu Cheng Qi decoction. The serum levels of creatine kinase isoenzyme (CK-MB) and lactate dehydrogenase (LDH) were detected using an automatic biochemical analyzer. In addition, myocardial Na⁺-K⁺-ATPase activity was analyzed using a spectrophotometric method and the mitochondrial membrane potential was measured by flow cytometry. Myocardial apoptosis was assessed using a TUNEL assay and pathological changes to the heart and pancreas were detected by hematoxylin and eosin staining. Compared with the rats in the sham group, rats in the SAP and decoction treatment groups exhibited significantly higher levels of serum CK-MB and LDH, apoptosis index and pathological scores, and had significantly lower levels of Na⁺-K⁺-ATPase activity and mitochondrial membrane potential. However, when compared with the SAP group, the serum levels of CK-MB and LDH, the pathological scores of the pancreas and heart, and the myocardial cell apoptosis index in the decoction treatment group were significantly lower. Furthermore, the Na⁺-K⁺-ATPase activity and mitochondrial membrane potential were significantly increased in the decoction treatment group when compared with the SAP group. Therefore, Lai Fu Cheng Qi decoction was shown to exert a protective effect on myocardial injury induced by SAP in rats.

Immunomodulatory therapies for acute pancreatitis

It is currently difficult for conventional treatments of acute pancreatitis (AP), which primarily consist of anti-inflammatory therapies, to prevent the progression of AP or to improve its outcome. This may be because the occurrence and progression of AP, which involves various inflammatory cells and cytokines, includes a series of complex immune events. Considering the complex immune system alterations during the course of AP, it is necessary to monitor the indicators related to immune cells and inflammatory mediators and to develop more individualized interventions for AP patients using immunomodulatory therapy. This review discusses the recent advances in immunomodulatory therapies. It has been suggested that overactive inflammatory responses should be inhibited and excessive immunosuppression should be avoided in the early stages of AP. The optimal duration of anti-inflammatory therapy may be shorter than previously expected (< 24 h), and appropriate immunostimulatory therapies should be administered during the period from the 3^rd d to the 14^th d in the course of AP. A combination therapy of anti-inflammatory and immune-stimulating drugs would hopefully constitute an alternative to anti-inflammatory drug monotherapy. Additionally, the detection of the genotypes of critical inflammatory mediators may be useful for screening populations of AP patients at high risk of severe infections to enable the administration of early interventions to improve their prognosis.

Effect of mesenchymal stem cells on renal injury in rats with severe acute pancreatitis

The aim of this study was to preliminarily investigate the effect of bone marrow mesenchymal stem cells (MSCs) on structural change of capillary endothelial barrier and expression variation of aquaporin 1 (AQP1) in kidney at the onset of renal injury caused by severe acute pancreatitis (SAP). Ninety male Sprague-Dawley (SD) rats were divided into the control group, the SAP group in which animals received induction of SAP and the MSCs-treated group in which SAP-induced animals were injected with MSCs. They were further subdivided according to the time point that the animals were killed; 6 h, 12 h and 24 h after the closure of the incision, serum, pancreatic and renal samples were collected, respectively. The level of serum amylase (AMY), creatinine (Cr) and blood urea nitrogen (BUN) were analysed, the change of pancreatic histology was assessed, the structural change of the renal interstitial capillaries was evaluated using the transmission electron microscope (TEM) and the location and expression of AQP1 in kidney were analysed using immunohistochemistry, quantitative polymerase chain reaction and Western blot. The outcomes showed that the level of serum AMY, Cr, BUN elevated, the damage of pancreatic tissue and renal capillary endothelial barrier was aggravated and the expression of AQP1 was reduced significantly after induced pancreatitis. But after treatments with MSCs, the elevation of AMY, Cr and BUN was inhibited, the damage of pancreatic tissue and renal interstitial capillary barrier was alleviated and the down-regulation of AQP1 was reversed. In summary, the MSCs therapy could alleviate renal injury in rats with SAP, the mechanism of which might be related to reduction of the damage to renal interstitial capillary endothelial barrier, and up-expression of AQP1 in kidney.

Effects of dexamethasone and Salvia miltiorrhiza on multiple organs in rats with severe acute pancreatitis

OBJECTIVE

To investigate the protective effects and mechanisms of action of dexamethasone and Salvia miltiorrhiza on multiple organs in rats with severe acute pancreatitis (SAP).

METHODS

The rats were divided into sham-operated, model control, dexamethasone treated, and Salvia miltiorrhiza treated groups. At 3, 6, and 12 h after operation, the mortality rate of different groups, pathological changes, Bcl-2-associated X protein (Bax) and nuclear factor-κB (NF-κB) protein expression levels in multiple organs (the pancreas, liver, kidneys, and lungs), toll-like receptor 4 (TLR-4) protein levels (only in the liver), intercellular adhesion molecule 1 (ICAM-1) protein levels (only in the lung), and terminal deoxynucleotidy transferase mediated deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL) staining expression levels, as well as the serum contents of amylase, glutamate-pyruvate transaminase (GPT), glutamic-oxaloacetic transaminase (GOT), blood urea nitrogen (BUN), and creatinine (CREA) were observed.

RESULTS

The mortality rate of the dexamethasone treated group was significantly lower than that of the model control group (P<0.05). The pathological changes in multiple organs in the two treated groups were relieved to different degrees (P<0.05 and P<0.01, respectively), the expression levels of Bax and NF-κB proteins, and apoptotic indexes of multiple organs were reduced (P<0.05 and P<0.01, respectively). The contents of amylase, GPT, GOT, BUN, and CREA in the two treated groups were significantly lower than those in model control groups (P<0.05 and P<0.01, respectively). The expression level of ICAM-1 protein in the lungs (at 3 and 12 h) in the dexamethasone treated group was significantly lower than that in the Salvia miltiorrhiza treated group (P<0.05). The serum contents of CREA (at 12 h) and BUN (at 6 h) of the Salvia miltiorrhiza treated group were significantly lower than those in the dexamethasone treated group (P<0.05).

CONCLUSIONS

Both dexamethasone and Salvia miltiorrhiza can reduce the inflammatory reaction, regulate apoptosis, and thus protect multiple organs of rats with SAP.

Coupled plasma filtration adsorption combined with continuous veno-venous hemofiltration treatment in patients with severe acute pancreatitis

BACKGROUND

Severe acute pancreatitis (SAP) still has a high mortality rate. Coupled plasma filtration adsorption (CPFA) and continuous veno-venous hemofiltration (CVVH) are 2 extracorporeal blood purification techniques. We hypothesized that CPFA combined with CVVH could preferentially improve prognosis and suppress clinical manifestations of SAP.

METHODS

In this observational cohort study, 25 patients with SAP were enrolled, in which 12 received CPFA plus CVVH treatment (group 1), and 13 received CVVH therapy (group 2). All the patients underwent a successive 10-day intervention. Clinical indicators were detected before or after the intervention and the results were compared between the 2 groups. The feasibility and the survival rate were evaluated on day 28.

RESULTS

Compared with group 2, oxygenation index (PaO(2)/FiO(2)), mean arterial pressure, serum amylase, and blood urine nitrogen showed significant differences (all P<0.01) and serum TNF-α, IL-1β, IL-6 were reduced and IL-10 was elevated with time in group 1 (all P<0.01). Liver functions, electrolyte, and acid-base balance did not show significant difference before and after the 10-day treatment with CPFA plus CVVH compared with CVVH (P>0.05). No therapy-related adverse reactions were noted in both groups. Twenty-eight-day survival rate of group 1 was higher than that in group 2 [91.7% (11/12) vs. 53.8% (7/13), P<0.05].

CONCLUSIONS

CPFA combined with CVVH was an effective and safe method for treatment of SAP patients, the mechanism being related to its effect on regulating the level of cytokines and serum amylase.

Protective effects of edaravone against acute necrotizing pancreatitis in rats

AIM: To investigate whether edaravone has protective effects against acute necrotizing pancreatitis (ANP) in rats and to explore the possible mechanisms involved.

METHODS: Ninety male Spraque-Dawley rats were randomly and equally divided into sham operation group, ANP group and edaravone treatment group (EDA group). ANP was induced in rats of the ANP and EDA groups by retrograde injection of 1.5% deoxycholate. The EDA group was injected with edaravone (6 mg/kg) via the tail vein immediately after ANP induction. The rats were sacrificed 6, 12, and 24 h after the operation. Pathological changes in the pancreas were observed and graded. Serum levels of amylase, tumor necrosis factor-alpha (TNF-α), endothelin-1 (ET-1) and soluble intercellular adhesion molecule-1 (sICAM-1), as well as malonic dialdehyde (MDA) content and superoxide dismutase (T-SOD) activity in pancreatic tissue were measured.

RESULTS: Compared to the sham operation group, pancreatic pathological scores, serum levels of amylase, TNF-α, ET-1 and sICAM-1, and the contents of MDA in pancreatic tissue were significantly increased, and T-SOD activity in pancreatic tissue was significantly decreased in the ANP group. Compared to the ANP group, pancreatic pathological scores, serum levels of TNF-α (6 h: 109.6 ng/L ± 49.0 ng/L vs 190.2 ng/L ± 46.6 ng/L, 12 h: 405.4 ng/L ± 116.3 ng/L vs 559.7 ng/L ± 203.9 ng/L, 24 h: 415.4 ng/L ± 164.6 ng/L vs 648.7 ng/L ± 222.1 ng/L, all P < 0.05), ET-1 (6 h: 45.6 ng/L ± 13.5 ng/L vs 66.0 ng/L ± 16.0 ng/L, 12 h: 83.5 ng/L ± 15.4 ng/L vs 96.8 ng/L ± 23.0 ng/L, 24 h: 85.1 ng/L ± 25.8 ng/L vs 103.9 ng/L ± 28.9 ng/L, all P < 0.05), and sICAM-1 (6 h: 0.58 ng/L ± 0.13 ng/L vs 0.78 ng/L ± 0.14 ng/L, 12 h: 0.78 ng/L ± 0.10 ng/L vs 0.94 ng/L ± 0.12 ng/L, 24 h: 0.96 ng/L ± 0.16 ng/L vs 1.24 ng/L ± 0.30 ng/L, all P < 0.05), and the contents of MDA in pancreatic tissue (6 h: 4.22 nmol/mgprot ± 0.40 nmol/mgprot vs 8.79 nmol/mgprot ± 0.80 nmol/mgprot, 12 h: 5.90 nmol/mgprot ± 0.51 nmol/mgprot vs 12.30 nmol/mgprot ± 1.02 nmol/mgprot, 24 h: 9.10 nmol/mgprot ± 0.84 nmol/mgprot vs 17.88 nmol/mgprot ± 1.43 nmol/mgprot, all P < 0.05) were reduced, and T-SOD activity was increased (6 h: 88.6 U/mgprot ± 7.1 U/mgprot vs 68.8 U/mgprot ± 10.5 U/mgprot, 12 h: 77.6 U/mgprot ± 6.8 U/mgprot vs 46.0 U/mgprot ± 8.9 U/mgprot, 24 h: 45.5 U/mgprot± 5.3 U/mgprot vs 27.8 U/mgprot ± 4.3 U/mgprot, all P < 0.05) in the EDA group. No significant differences were observed in serum levels of amylase between the ANP and EDA groups.

CONCLUSION: Edaravone can eliminate the excessive generation of oxygen free radicals, down-regulate the expression of inflammatory cytokines, and reduce tissue injury in rats with ANP.

Correlation between early sublingual small vessel density and late blood lactate level in critically ill surgical patients

BACKGROUND

Surgical stress may cause excessive inflammation and lead to microcirculatory dysfunction. The hypothesis of this study was that early microcirculatory dysfunction may result in anaerobic glycolysis and lead to elevated blood lactate levels in patients admitted to surgical intensive care units.

METHODS

This prospective observational study enrolled adult patients admitted to surgical intensive care units after general surgery or thoracic surgery. We measured blood lactate levels before the operation and at 1 h and 24 h after the operation. We obtained images of sublingual microcirculation using a sidestream dark field video microscope and analyzed them employing automated analysis software.

RESULTS

A total of 31 patients completed the study. Perioperative total and perfused small vessel densities were lower in patients with a blood lactate level ≥3 mmol/L. We observed a significant correlation between the total small vessel density at 1 h and the blood lactate level at 24 h (r = -0.573; P = 0.001). In addition, we saw a significant correlation between the perfused small vessel density at 1 h and the blood lactate level at 24 h (r = -0.476; P = 0.008).

CONCLUSIONS

Early total and perfused small vessel density may be used as an early predictor or therapeutic goal for critically ill surgical patients in further studies.

Synergetic effect of yihuo qingyi decoction (see text) and recombinant staphylokinase in treatment of severe acute pancreatitis of rats

OBJECTIVE

To investigate the effect of recombinant staphylokinase (r-Sak) and the Chinese medicine Yihuo Qingyi Decoction ((see test) Herbal decoction for severe acute pancreatitis) in the treatment of the severe acute pancreatitis (SAP) in rats, and to observe the synergistic effect of the two.

METHODS

One hundred and sixty-two adult male SD rats with the body mass of 250-280 g were randomly divided into the following 5 groups: sham operation group (n = 18), control group (n = 36), Yihuo Qingyi Decoction treatment group (n = 36), r-Sak treatment group (n = 36), and Yihuo Qingyi Decoction plus r-Sak treatment group (n = 36). The SAP ratmodel was prepared by retrograde injection of 5% sodium taurocholate into the cholangiopancreatic duct. Two days before modeling, Yihuo Qingyi Decoction was intragastrically administrated, and r-Sak was intraperitoneally injected. The survival rate within 18 h after modeling was determined. The pancreatic blood flow, the weight of ascites, and the serum amylase and lipase were investigated at 6 h, 12 h, and 18kh after modeling, and the pancreatic tissue was examined under light microscopy to see its pathological change.

RESULTS

The 18 h survival count of group A, B, C, D and E rats was 9, 2, 6, 7 and 8 respectively. After r-Sak and Yihuo Qingyi Decoction intervention, the serum amylase and lipase and the weight of ascites were significantly decreased, especially in group E.18 h after modeling, the level of the serum amylase and lipase and the weight of ascites in group E was 1 100 +/- 118 U x L(-1), 1 000 +/- 150 U x L(-1) and 13.40 +/- 1.80 g respectively, obviously lower than that of group B (P < 0.05). After SAP was induced, the pancreatic blood flow showed a tendency to decrease, but the decrease extent in the treatment groups was smaller than that in the control group. 18h after modeling, the pancreatic blood flow in group B and group E was 30.16 +/- 8.96 mL x 100 g(-1) x min(-1), and 129.10 +/- 42.58 mL x 100 g(-1) x min respectively, there was significant difference (P < 0.05). The pathological change of the pancreatic tissue was alleviated in the treatment groups.

CONCLUSION

Both r-Sak and Yihuo Qingyi Decoction play a beneficial role in the treatment of rat SAP and there is a synergistic effect between the two.

Differential effects of endothelins on histological and ultrastructural changes and trypsinogen activation in the secretagogue-induced acute pancreatitis in rats

The role of endothelins in acute pancreatitis remains obscure. To assess the effects of endothelins (ETs) in early (4 h) caerulein-induced acute pancreatitis (AP) in rats, ET-1, ET-2 and ET-3 (0.5 or 1.0 nmol/kg) were applied twice with i.p. caerulein (2×40 μg/kg) at 1h interval. Histological and ultrastructural examinations of pancreases and the assay of trypsinogen activation in whole homogenate were performed. All ETs, especially ET-1 at the higher dose, decreased inflammatory cell infiltration despite an increase in the edema score. The vacuolization and necrosis of acinar cells were slightly increased after the lower dose of ET-1 and ET-2. Ultrastructural changes were generally improved after the higher dose of ETs. Trypsinogen activation increased from 4.8±1.3% in control to 18.4±3.8% in AP (p<0.01). It was attenuated to 6.4±1.3% (p<0.01) by the higher dose of ET-1 and to 8.8±1.5% (p<0.05) by the lower dose of ET-3. In summary, ETs, especially ET-1 at the higher dose, were found to have some beneficial effects on morphological changes and trypsinogen activation in the pancreas in early caerulein-induced AP.

Fish oil-supplemented parenteral nutrition in severe acute pancreatitis patients and effects on immune function and infectious risk: a randomized controlled trial

The human leukocyte antigen (HLA)-DR expression on monocytes and plasma Interleukin (IL)-10 levels are key indicators of immune response during the acute phase of severe acute pancreatitis (SAP). We designed a pilot study to investigate whether omega-3 fatty acids (FAs) supplemented parenteral nutrition (PN) could improve immune response in SAP patients. Fifty-six SAP patients were enrolled (28 patients in each group) and received isocaloric and isonitrogenous parenteral nutrition, providing 1.0 g/kg/day standard soybean-oil based fat (omega-6 FAs group) or 0.8 g/kg/day soybean oil +0.2 g/kg/day omega-3 FAs based fat (omega-3 FAs group). IL-10, HLA-DR and the ratio of CD4(+) to CD8(+) were determined before PN treatment and on day 6 after starting PN. The infection and surgery rates were recorded until hospital discharge. A significant IL-10 increase was associated with the administration of omega-3 FAs (p = 0.04, vs omega-6 FAs group). Monocyte HLA-DR expression improved in both groups after 5 days of PN treatment. This increase was significantly higher in the omega-3 FAs group compared to omega-6 FAs (p = 0.01). There was no significant difference of CD4(+)/CD8(+), infection and surgery rates between the two groups. In conclusion, omega-3 FAs supplemented PN can elevate the IL-10 level and HLA-DR expression in SAP patients. A larger trial is required to see whether omega-3 FAs supplemented PN treatment in SAP patients would result in better clinical outcomes than omega-6 FAs.

Plasma tissue factor pathway inhibitor levels in patients with acute pancreatitis

BACKGROUND

In acute pancreatitis (AP), disorders of the coagulation-fibrinolysis system are closely related to the severity of the AP and to organ dysfunctions. We previously reported that plasma tissue factor (TF) levels were elevated in patients with AP, particularly in cases of alcoholic AP with pancreatic necrosis. Tissue factor pathway inhibitor (TFPI) is a key regulator of the extrinsic coagulation pathway, but plasma TFPI levels in AP have not yet been determined.

METHODS

Plasma TFPI concentrations were measured by enzyme-linked immunosorbent assay in 44 patients with AP on admission. The relationships between AP severity, pancreatic necrosis, organ dysfunction, infection, and prognosis were analyzed.

RESULTS

Plasma TFPI levels were increased in AP patients compared with healthy volunteers. Plasma TFPI levels in severe AP were greater than those in mild AP. Plasma TFPI levels significantly correlated with Ranson score, APACHE II score, and Japanese severity score. Plasma TFPI levels in patients with pancreatic necrosis were greater than those in patients without pancreatic necrosis. Plasma TFPI levels in patients with organ dysfunction were greater than those in patients without organ dysfunction. In patients with pancreatic necrosis, the TF/TFPI ratios in non-survivors were lower than those in survivors. Moreover, the mortality rates in patients with TF/TFPI ratios > or = 2.0 were lower than those in patients with TF/TFPI ratios < 2.0.

CONCLUSIONS

Plasma TFPI levels were significantly increased in patients with AP, and the elevation was markedly related to the severity, pancreatic necrosis and organ dysfunctions. The imbalance of TF and TFPI may influence the disease state and thereby the prognosis in AP.

Effect of baicalin on inflammatory mediator levels and microcirculation disturbance in rats with severe acute pancreatitis

OBJECTIVES

To investigate the effect of bacailin on inflammatory mediators and microcirculation disturbance in severe acute pancreatitis (SAP) rats and explore its therapeutic mechanism.

METHODS

The rats were randomly divided into SAP group, baicalin-treated group and sham operated group. At 3, 6, and 12 hours after operation, we examined the mortality rate of rats, ascites volume, and pancreatic pathological changes in each group and determined the contents of inflammatory mediators in blood as well as the changes in blood viscosity.

RESULTS

Compared with SAP group, treatment with baicalin is able to improve the pathological damage of the pancreas, reduce the contents of multiple inflammatory mediators in blood, decrease the amount of ascitic fluid, and reduce the mortality rates of SAP rats. The low-shear whole blood viscosity in baicalin-treated group (at 3 hours) as well as the high-shear and low-shear whole blood viscosity in baicalin-treated group (at 12 hours) were significantly lower than that in SAP group.

CONCLUSIONS

Baicalin has good prospects in the treatment for SAP because it can exert therapeutic effects on this disease through inhibiting the production of inflammatory mediators, decreasing blood viscosity, improving microcirculation, and mitigating the pathological damage of the pancreas.

Efficacy and mechanism of Salvia miltiorrhizae injection in the treatment of rats with severe acute pancreatitis

To study the efficacy and mechanism of Salvia miltiorrhizae injection in the treatment of severe acute pancreatitis. SAP rat models were prepared and randomly divided into model control group and treated group. The sham-operated group was also set. At 3, 6 and 12 h after operation, the mortality rate, ascitic volumes, pathological changes in the pancreas, contents of amylase and endotoxin in plasma as well as IL-6, IL-18, ET-1 and NO in serum, the staining intensity of Bax and NF-kappaB p56 proteins, and the changes in apoptosis index of pancreatic cells in rats in each group were observed. The pathological severity scores (at 3, 6 and 12 h after operation), contents of plasma endotoxin (at 6 and 12 h after operation) and serum IL-6 (at 6 and 12 h after operation) were significantly lower than those in model control group (P < 0.05, P < 0.01 and P < 0.01, respectively); the staining intensity and the product of the staining intensity and positive staining rate of Bax protein in the pancreas were significantly higher than those in model control group (P < 0.01). Salvia miltiorrhizae is able to reduce the contents of plasma endotoxin and serum IL-6, promote the expression of Bax protein in pancreas, improve the pathological changes in the pancreas, and decrease the mortality rate of rats, thereby showing therapeutic effect on rats with SAP.

Effects of Salvia miltiorrhiza on intercellular adhesion molecule 1 protein expression in the lungs of rats with severe acute pancreatitis or obstructive jaundice

OBJECTIVE

The objective of the study was to observe the effects of Salvia miltiorrhiza on intercellular adhesion molecule 1 (ICAM-1) protein expression in the lungs of rats with severe acute pancreatitis (SAP) or obstructive jaundice (OJ).

METHODS

A total of 288 rats were used for SAP- and OJ-associated experiments. The rats were randomly divided into sham-operated, model control, and treated group. According to the difference of time points after operation, the SAP rats of each group were subdivided into 3-, 6-, and 12-hour groups, whereas the OJ rats were divided into 7-, 14-, 21-, and 28-day groups. The contents of interleukin (IL) 6, IL-18, nitric oxide, malondialdehyde, and superoxide dismutase in serum were determined, and pathological changes and ICAM-1 protein expression in the lungs were observed.

RESULTS

Compared with the respective model control groups, in treated groups of SAP and OJ rats, the numbers of dead rats declined; serum superoxide dismutase content significantly increased, and serum IL-18, IL-6, and malondialdehyde contents were significantly decreased; the positive staining intensity of ICAM-1 protein in the lungs decreased significantly (P < 0.05, P < 0.01, or P < 0.001); and pathological changes in the lungs were relieved.

CONCLUSIONS

Salvia miltiorrhiza plays a positive role in the protection of the lungs of SAP and OJ rats.

Omega-3 fatty acids-supplemented parenteral nutrition decreases hyperinflammatory response and attenuates systemic disease sequelae in severe acute pancreatitis: a randomized and controlled study

BACKGROUND

The objective of this study was to investigate whether altering the fatty acid (FA) profile by omega-3 FA supplementation affects inflammatory response and systemic disease sequelae in severe acute pancreatitis.

METHODS

Forty severe acute pancreatitis patients were enrolled and randomly assigned to receive parenteral nutrition (PN) for 5 days in a double-blind manner. Patients received PN with identical amounts of amino acids (1.25 g/kg/d), glucose (3 g/kg/d), and fat (1 g/kg/d) but different lipid compositions: the control group received a soybean oil (SO; Lipovenos 20%; Fresenius, Germany)-based fat solution and the omega-3 FA group was supplemented with 0.15 - 0.2 g/kg/d fish oil (FO; Omegaven 10%; Fresenius, Germany). Serum concentrations of eicosapentaenoic acid (EPA), interleukin-6, C-reactive protein (CRP), white blood cell count, and routine respiratory and renal parameters were measured before PN, and again on day 6 after starting PN. Outcomes such as infection morbidity, mortality, intensive care unit time, and length of hospital stay were recorded.

RESULTS

Patients treated with FO had a significantly higher EPA concentration (P < .01), lower CRP level (P < .05), and better oxygenation index (P < .05) after 5 days of PN. Moreover, the number of days of continuous renal replacement therapy (CRRT) in the omega-3 FAs group was significantly less than that in the control group (P < .05).

CONCLUSIONS

PN supplemented with omega-3 FAs diminishes the hyperinflammatory response by the EPA increase and the proinflammatory cytokine decrease in severe acute pancreatitis. This, together with improved respiratory function and shortened CRRT time, suggests that the systemic response to pancreatic and organ injury is attenuated.

Pathophysiological role of platelets and platelet system in acute pancreatitis

The most successful approach for restoring normal long-term glucose homeostasis in type I diabetes mellitus is whole-organ pancreas transplantation. Graft pancreatitis is observed in up to 20% of patients and may lead to loss of the transplanted organ. Several pathophysiological events have been implicated in this form of pancreatitis. The most important cause of early graft pancreatitis is ischemia/reperfusion (I/R)-related disturbance of microvascular perfusion with subsequent hypoxic tissue damage. Recently, considerable evidence accumulated that, among a variety of other pathophysiological events, the activation of platelets can contribute to I/R injury in the course of acute pancreatitis experimentally and clinically. This review summarizes the events affecting platelet function and, therefore, pancreatic microcirculation leading to acute pancreatitis. Therapeutic approaches and own results are presented.

The pathogenic mechanism of severe acute pancreatitis complicated with renal injury: a review of current knowledge

The onset of severe acute pancreatitis (SAP) is clinically harmful as it may rapidly progress from a local pancreatic inflammation into proemial systemic inflammatory reactions. Patients with SAP have a high mortality, with most cases of death resulting from complications involving the failure of organs other than the pancreas. The distinctive feature of SAP is that once it starts, it may aggrevate the clinical condition of the patient continuously, so that the levels of injury to the other organs surpass the severity of the pancreatic lesion, even causing multiple organ failure and, ultimately, death. In clinical practice, the main complications in terms of organ dysfunctions are shock, acute respiratory failure, acute renal failure, among others. The acute renal injury caused by SAP is not only able to aggravate the state of pancreatitis, but it also develops into renal failure and elevates patients' mortality. Studies have found that the injury due to massive inflammatory mediators, microcirculation changes and apoptosis, among others, may play important roles in the pathogenic mechanism of acute renal injury.

Mechanism of acute pancreatitis complicated with injury of intestinal mucosa barrier

Acute pancreatitis (AP) is a common acute abdomen in clinic with a rapid onset and dangerous pathogenetic condition. AP can cause an injury of intestinal mucosa barrier, leading to translocation of bacteria or endotoxin through multiple routes, bacterial translocation (BT), gut-origin endotoxaemia, and secondary infection of pancreatic tissue, and then cause systemic inflammatory response syndrome (SIRS) or multiple organ dysfunction syndrome (MODS), which are important factors influencing AP's severity and mortality. Meanwhile, the injury of intestinal mucosa barrier plays a key role in AP's process. Therefore, it is clinically important to study the relationship between the injury of intestinal mucosa barrier and AP. In addition, many factors such as microcirculation disturbance, ischemic reperfusion injury, excessive release of inflammatory mediators and apoptosis may also play important roles in the damage of intestinal mucosa barrier. In this review, we summarize studies on mechanisms of AP.

Study progress on mechanism of severe acute pancreatitis complicated with hepatic injury

Study on the action mechanism of inflammatory mediators generated by the severe acute pancreatitis (SAP) in multiple organ injury is a hotspot in the surgical field. In clinical practice, the main complicated organ dysfunctions are shock, respiratory failure, renal failure, encephalopathy, with the rate of hepatic diseases being closely next to them. The hepatic injury caused by SAP cannot only aggravate the state of pancreatitis, but also develop into hepatic failure and cause patient death. Its complicated pathogenic mechanism is an obstacle in clinical treatment. Among many pathogenic factors, the changes of vasoactive substances, participation of inflammatory mediators as well as OFR (oxygen free radical), endotoxin, etc. may play important roles in its progression.

Neutrophils from acute pancreatitis patients cause more severe in vitro endothelial damage compared with neutrophils from healthy donors and are differently regulated by endothelins

OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Pathophysiological role of platelets in acute experimental pancreatitis: influence of endothelin A receptor blockade

The potential pathophysiological role of platelet-endothelium interactions was investigated during ischemia/reperfusion (I/R), and the effect of a selective endothelin(A) receptor antagonist (ET(A)-RA) was evaluated in an acute pancreatitis model. Acute pancreatitis was induced by warm ischemia (60 min) in Wistar rats, and its effects with and without antagonist treatment were investigated. Equivalent sham-operated animals were also studied. Microcirculatory changes were assessed by in vivo microscopy, and serum levels for lipase/amylase and histological specimens were investigated. Capillary constriction to 83.7 +/- 6.7% of sham-operated diameters was observed after 60 min of ischemia. A capillary density of 56.8 +/- 9.3% of the sham-operated group (396.3 +/- 15.8 mm(-1)) was measured after reperfusion. Stagnant leukocytes (329.5 +/- 30.4%) and platelets (337.5 +/- 32.3%) increased in postcapillary venules (P < 0.05). Administration of the ET(A)-RA significantly reduced I/R injury. Capillary diameters were maintained (101.4 +/- 4.5%), and capillary density was improved to 73.3 +/- 7.6% of sham-operated animals (P < 0.05). Stagnant leukocytes (152.3 +/- 10.6%) and platelets (207.1 +/- 19.8%) in sinusoids and postcapillary venules were reduced (P < 0.05). The extent of acute pancreatitis was reduced in the therapy group as indicated by serum lipase/amylase values and histological tissue damage (P < 0.05). Thus, ET(A)-RA therapy was effective in reducing I/R-induced pancreatitis in this experimental model.

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Endothelin-1 receptor antagonist (LU-135252) improves the microcirculation and course of TNBS colitis in rats

The role of microcirculation in the pathogenesis and course of chronic inflammatory bowel disease is still unclear. The aim of this study was the evaluation of the role of microcirculation in colitis activity in the rat TNBS (trinitrobenzenesulfonic acid) colitis model using endothelin-1 and a selective endothelin-1 receptor antagonist (LU-135252). Target parameters were capillary blood flow, functional capillary density, vascular permeability, and leukocyte sticking as well as recording of hematocrit, weight course, diuresis, stool quality, and degree of inflammation using a histological colitis score. The acute phase of TNBS colitis is characterized by an extensive disturbance of microcirculation (a significant decrease in capillary blood flow and capillary density and a significant increase in capillary permeability and leukocyte sticking in the mucosa). There is also a significant increase in hematocrit and a significant decrease in diuresis and weight. An exogenous supply of endothelin-1 does not lead to an aggravation of these disorders because of a possible blockage of the endothelin-1 receptors by endogenous endothelin-1 in this florid inflammatory phase. Applying the selective endothelin-1 receptor A antagonist LU-135252 leads to a significant improvement of all microcirculatory parameters and clinical findings compared to the untreated colitis group. Direct improvement of capillary blood flow in the early phase of colitis leads to reduced colitis activity, which underscores the pathogenetic role of the microcirculation in the progression of colitis.

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Elevation of plasma tissue factor levels in patients with severe acute pancreatitis

BACKGROUND

Coagulative disorders are known to occur in severe acute pancreatitis (SAP), and they are related to its severity and organ dysfunctions. Tissue factor (TF) is a transmembrane glycoprotein that activates the extrinsic pathway of the blood coagulation cascade. Plasma TF levels increase in patients with sepsis and acute coronary syndrome. However, plasma TF levels in SAP have not yet been reported.

METHODS

We measured plasma TF antigen levels by enzyme-linked immunosorbent assay in 36 patients with acute pancreatitis at the time of admission. The relationships between their plasma TF levels and various factors (severity, etiology, pancreatic necrosis, organ dysfunction, and prognosis) were analyzed. The utility of plasma TF as a clinical marker was evaluated.

RESULTS

Plasma TF levels significantly increased in patients with SAP compared with healthy volunteers and drinkers, respectively. Plasma TF level in alcoholic SAP with pancreatic necrosis was significantly higher than that in alcoholic SAP without pancreatic necrosis or that in nonalcoholic SAP with pancreatic necrosis. The incidence of an abnormally high level of plasma TF was 63.6% in alcoholic SAP with pancreatic necrosis. The area under the ROC curve of plasma TF for detection of pancreatic necrosis in alcoholic SAP was 0.773 and was superior to those of Japanese severity score and lactate dehydrogenase.

CONCLUSIONS

Plasma TF levels were elevated in patients with SAP, particularly in those with alcoholic SAP with pancreatic necrosis, suggesting that TF may be closely related to the development of pancreatic necrosis in alcoholic SAP and that the plasma TF level may be a useful marker for it.

Disturbances of the microcirculation in acute pancreatitis

BACKGROUND

Severe acute pancreatitis is characterized by pancreatic necrosis, resulting in local and systemic inflammation. Pancreatitis affects both the systemic and pancreatic vasculature. This review focuses on the underlying processes involved in the changes of microvascular anatomy following acute pancreatitis.

METHODS

A Medline/PubMed search (January 1966 to December 2005) with manual cross-referencing was conducted. All relevant articles investigating the pancreatic microcirculatory anatomy and the effect of pancreatitis on the microcirculation were included.

RESULTS

The pancreas is susceptible to ischaemic insult, which can exacerbate acute pancreatitis. There is also increasing evidence of pancreatic and systemic microvascular disturbances in the pathogenesis of pancreatitis, including vasoconstriction, shunting, inadequate perfusion, and increased blood viscosity and coagulation. These processes may be caused or exacerbated by ischaemia-reperfusion injury and the development of oxygen-derived free radicals.

CONCLUSION

Acute pancreatitis impairs the pancreatic and systemic microcirculation, which is a key pathological process in the development of severe necrotizing disease.

Hemoconcentration is a poor predictor of severity in acute pancreatitis

AIM

To determine whether the hematocrit (Hct) at admission or at 24 h after admission was associated with severe acute pancreatitis (AP), organ failure (OF), and pancreatic necrosis.

METHODS

A total of 336 consecutive patients with a first AP episode were studied. Etiology, Hct values at admission and at 24 h, development of severe AP according to Atlanta's criteria, pancreatic necrosis, OF and mortality were recorded. Hemoconcentration was defined as Hct level >44% for males and >40% for females. The t-test and chi2 test were used to assess the association of hemoconcentration to the severity, necrosis and OF. Diagnostic accuracy was also determined.

RESULTS

Biliary disease was the most frequent etiology (n = 148). Mean Hct levels at admission were 41+/-6% for females and 46+/-7% for males (P<0.01). Seventy-eight (23%) patients had severe AP, and OF developed in 45 (13%) patients. According to contrast-enhanced computed tomography scan, 36% (54/150) patients showed pancreatic necrosis. Hct levels were elevated in 58% (55/96) and 61% (33/54) patients with interstitial and necrotizing pancreatitis, respectively. Neither Hct levels at admission nor hemoconcentration at 24 h were associated with the severity, necrosis or OF. Sensitivity, specificity and positive predictive values for both determinations were very low; and negative predictive values were between 61% and 86%, being the highest value for OF.

CONCLUSION

Hct is not a useful marker to predict a worse outcome in acute pancreatitis. In spite of the high negative predictive value of hemoconcentration, the prognosis gain is limited due to an already high incidence of mild disease.

Selective COX-2 inhibition reduces leukocyte sticking and improves the microcirculation in TNBS colitis

The role of cyclooxygenase-2 inhibitors in the course of experimental colitis is controversially discussed. The aim of this study was to evaluate leukocyte-endothelium interaction and colitis activity after applying the selective cyclooxygenase-2 inhibitor NS-398 in a rat trinitrobenzene sulfonic acid (TNBS) colitis model. The acute phase of TNBS colitis is characterized by a significant reduction of capillary blood flow, capillary density, diuresis, and weight and a significant increase in capillary permeability, leukocyte sticking, and hematocrit. Applying the selective cyclooxygenase-2 inhibitor NS-398 leads to a significant improvement of all microcirculatory parameters and clinical findings compared to the (untreated) colitis group. There are no histopathological differences between the individual colitis groups. Acute colitis is characterized by an extensive disturbance of microcirculation together with signs of systemic inflammatory response syndrome. These alterations are significantly improved by inhibiting cyclooxygenase-2. The results support the described correlation between cyclooxygenase activation and leukocyte-endothelium interaction. Moreover, they underscore the postulated relation between leukocyte-endothelium interaction and capillary blood flow.

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Effect of endothelin-1 receptor antagonists on histological and ultrastructural changes in the pancreas and trypsinogen activation in the early course of caerulein-induced acute pancreatitis in rats

AIM: To assess the effect of non-selective ET_A/B (LU 302872) and selective ET_A (LU 302146) antagonist on pancreatic histology and ultrastructure of acinar cells in connection with trypsinogen activation in early caerulein-induced AP.

METHODS: Male Wistar rats with caerulein-induced AP, lasting 4 h, were treated i.p. with 10 and 20 mg/kg b.w. of each antagonist. Edema, inflammatory infiltration, necrosis and vacuolization of acinar cells in the pancreas were scored at 0-3 scale. Free active trypsin (FAT), total potential trypsin (TPT) after activation with enterokinase, and index of trypsinogen activation (%FAT/TPT) were assayed in pancreatic homogenates.

RESULTS: In untreated AP, the edema, inflammatory infiltration, necrosis and vacuolization increased as compared to control healthy rats (P<0.01). None of the treatment exerted any meaningful effect on the edema and inflammatory infiltration. The selective antagonist increased slightly the necrosis score to 0.82±0.06 at higher dose (P<0.05) vs 0.58±0.06 in untreated AP. The non-selective antagonist increased slightly the vacuolization score to 2.41±0.07 at higher dose (P<0.01) vs 1.88±0.08 in untreated AP. The decrease in the number of zymogen granules, disorganization of endoplasmic reticulum, autophagosomes and cytoplasmic vacuoles were more prominent in treated AP than in untreated AP groups. %FAT/TPT in untreated AP increased about four times (18.4±3.8 vs 4.8±1.3 in control group without AP, P<0.001). Treatment of AP with both antagonists did not affect significantly augmented trypsinogen activation.

CONCLUSION: The treatment with endothelin-1 receptors (non-selective ET_A/B and selective ET_A) antagonists has essential effect neither on the edema and inflammatory infiltration nor on trypsinogen activation observed in the early course of caerulein-induced AP. Nevertheless a slight increase of the necrosis and vacuolization score and some of the ultrastructural data could suggest the possibility of their undesired effects in caerulein-induced AP at investigated doses.

Admission hematocrit: a simple, useful and early predictor of severe pancreatitis

Existing predictor systems of severe pancreatitis are cumbersome and can require up to 48 hr to complete. This study aimed to determine whether useful likelihood ratios exist for the prediction of severe pancreatitis, corresponding to various ranges of admission hematocrit. A retrospective cohort of 200 patients admitted with acute pancreatitis was identified. Likelihood ratios were calculated for a priori defined hematocrit ranges. Using multivariate logistic regression, initial hematocrit was evaluated as a predictor of severe pancreatitis as defined a priori by local and/or systemic complications (Atlanta criteria, 1992). Planned subgroup analysis was performed on those with a hematocrit >50%, stratified by 24-hr hematocrit. Fourteen patients (7%) developed severe pancreatitis. Likelihood ratios were 0.45, 0.70, and 7.5 for hematocrit ranges of < or =45, 45.1-49.9, and > or =50%, respectively. Hematocrit (as increases by 5%) was a significant predictor of severe pancreatitis (odds ratio [OR] = 2.8; P = 0.001), length of stay (P < 0.0001), necrosis (OR = 3.9; P = 0.001), and need for intensive care (OR 4.5; P = 0.002). The negative predictive value of the lowest range and positive predictive value of the highest range were 97% (95% CI: 92-99%) and 37% (16-62%), respectively. Lack of normalization of hematocrit by 24 hr did not predict severe pancreatitis. Initial hematocrit appears to be an early, simple, and useful predictor of severe pancreatitis. A normal 24-hr hematocrit does not appear to alter the prediction made by the initial hematocrit.

Heparin improves organ microcirculatory disturbances in caerulein-induced acute pancreatitis in rats

AIM: Microcirculatory disturbances are important early pathophysiological events in various organs during acute pancreatitis. The aim of the study was to evaluate changes in microperfusion of the pancreas, liver, kidney, stomach, colon, skeletal muscle, and to investigate the influence of heparin on the organ microcirculation in caerulein-induced experimental acute pancreatitis.

METHODS: Acute pancreatitis was induced by 4 intraperitoneal injections of caerulein (Cn) (15 μg/kg). The organ microcirculation was measured by laser Doppler flowmetry. Serum interleukin 6 and hematocrit levels were analysed.

RESULTS: Acute pancreatitis resulted in a significant drop of microperfusion in all examined organs. Heparin administration (2 ± 2.5 mg/kg) improved the microcirculation in pancreas (36.9% ± 4% vs 75.9% ± 10%), liver (56.6% ± 6% vs 75.2% ± 16%), kidney (45.1% ± 6% vs 79.3% ± 5%), stomach (65.2% ± 8% vs 78.1% ± 19%), colon (69.8% ± 6% vs 102.5% ± 19%), and skeletal muscle (59.2% ± 6% vs 77.9% ± 13%). Heparin treatment lowered IL-6 (359.0 ± 66 U/mL vs 288.558 U/mL) and hematocrit level (53% ± 4% vs 46% ± 3%).

CONCLUSION: Heparin administration has a positive influence on organ microcirculatory disturbances accompanying experimental Cn-induced acute pancreatitis.

Endothelin receptor antagonists are not beneficial in the therapy of acute experimental pancreatitis

BACKGROUND AND AIM

Due to increased capillary permeability and the early appearance of vasoactive and toxic agents, patients suffering from necrotizing pancreatitis frequently develop a systemic inflammatory response syndrome (SIRS). Endothelin, a potent vasoconstrictor, is thought to play a major role in these changes via the regulation of microcirculation. An improved outcome of acute experimental necrotizing pancreatitis by blocking the endothelin receptors ETA and ETB, either selectively (only ETA) or unselectively (ETA and ETB), has been suggested. The aim of this study was to investigate further the beneficial effects of new, highly potent endothelin-receptor (ET-R) antagonists in acute experimental pancreatitis.

METHODS

The influence of the selective ET-RA antagonist BSF208075 (1 mg/kg) on mortality was studied in three severity groups of acute necrotizing pancreatitis (retrograde injection of 4%, 5% and 6% of sodium taurocholate into the main pancreatic duct). The effects of the selective ET-RA antagonists LU135252 (LU13) and BSF208075 (BSF20) and of the unselective endothelin receptor (ET-R(A/B)) antagonist BSF420627 (BSF42) were additionally analyzed in 4% taurocholate-induced necrotizing pancreatitis. Furthermore, the significance of variable doses of the endothelin receptor antagonist LU13 (1 mg/kg, 3 mg/kg and 100 mg/kg) was determined in a 4% sodium taurocholate model and in a cerulein pancreatitis model.

RESULTS

Prophylactic ET-R antagonism increased the mortality rate in the 4% sodium taurocholate-induced pancreatitis. No reduction in pancreatic damage after induction of taurocholate pancreatitis was found by ET-R blockage. Application of ET-R antagonists had no beneficial influence in ascites development. However, administration of LU13 (100 mg/kg) resulted in a non-significant increase in pancreatic oedema, whereas peritoneal necrosis was not affected.

CONCLUSION

The selective and unselective ET-R antagonists BSF20, BSF42 and LU13 failed to improve survival and pancreatic damage during acute experimental pancreatitis. Therefore, previously reported beneficial effects of ET-R antagonists in experimental acute pancreatitis have to be critically evaluated before conclusions for further clinical development are made.

The endothelin-1 receptor antagonists ameliorate histology and ultrastructural alterations in the pancreas and decrease trypsinogen activation in severe taurocholate pancreatitis in rats

The role of potent vasoconstrictor endothelin-1 (ET-1) in acute pancreatitis (AP) remains controversial. The aim was to compare the effect of nonselective ET RA/B (LU-302872) and selective ET RA (LU-302146) antagonists on pancreatic histology, ultrastructure and trypsinogen activation in severe taurocholate AP in rats. Male Wistar rats with AP were treated with an intraperitoneous injection of 1, 5 and 10 mg/kg of body weight of each antagonist at 0, 6, 12 and 18 h after taurocholate administration. After 24 h, the samples of pancreases were taken for histological and ultrastructural examinations and for assessment of trypsinogen activation. Both antagonists, at all investigated doses, decreased the damage to the acinar cells detected in the light microscope and ultrastructurally. Trypsinogen activation increased to 29.7 +/- 3.9% in the AP untreated in comparison to the control group [12.7 +/- 1.4% (P<0.001)]. This increase was attenuated to 13.8 +/- 2.2% in AP treated with a high dose of the nonselective antagonist and to 8.4 +/- 1.7% with low dose of selective antagonist. The obtained results indicate that ET-1 could participate in the damage to the pancreas during AP. Both antagonists of ET-1 receptors exerted a similar beneficial effect on the morphological changes of the pancreas in AP. One of the probable mechanism could be the attenuation of trypsinogen activation.

Impact of chronic and acute high-fat feeding on acute experimental pancreatitis complicated by endotoxinaemia

BACKGROUND

Obesity is associated with increased severity in patients with acute pancreatitis (AP). The underlying mechanisms are unknown. Genetically obese rats exhibit decreased survival rate in experimental AP, but the clinical relevance of this model of obesity may be questioned. It is proposed that development of organ failure in AP occurs in two stages: initial priming of leucocytes followed by a second inflammatory attack. The aim was to evaluate the impact of diet-induced obesity on outcome in a 'two-hit' model of AP.

METHODS

Lipopolysaccharide (LPS) was injected i.p. 3 h after retrograde bile duct infusion of sodium taurocholate in rats. Three experiments were done: 1) an LPS dose-response experiment, 2) chronic high-fat feeding (HF) for 16 weeks, and 3) acute HF for 10 days. Control rats received normal chow. Obesity, morphology and survival rate were assessed.

RESULTS

LPS dose-dependently decreased survival rate and increased morphological severity. HF increased weight, intra-abdominal and liver fat. Only acute HF induced hyperlipidaemia. In AP, acute obese rats exhibited less pancreatic inflammation, but total histological severity between groups was not different. In the chronic experiment only obese animals succumbed before 24 h of pancreatitis, but 72-h survival rate was not statistically different in either high-fat experiment.

CONCLUSION

An addition of LPS to AP decreases survival rate and intensifies the peri-pancreatic processes. Despite significant obesity, neither hyperlipidaemia nor increased intra-abdominal or hepatic fat influenced local pancreatic injury or survival negatively. The amount of fat per se seems not to be responsible for the deleterious influence of obesity on acute pancreatitis.

Endothelin(A) receptor blockade reduces ischemia/reperfusion injury in pig pancreas transplantation

OBJECTIVE

The effect of prophylactic administration of a selective endothelin(A) receptor antagonist (ET(A)-RA) on ischemia/reperfusion injury in an experimental model of graft pancreatitis after pancreas transplantation was evaluated.

SUMMARY BACKGROUND DATA

It is well established that endothelin-1 (ET-1), a powerful vasoconstrictor, plays an important role in the development of pancreatitis. Recent studies have shown a beneficial effect of endothelin receptor antagonists in the therapy for experimental pancreatitis.

METHODS

Relevant ischemia/reperfusion injury was induced in pig pancreas transplants after 6 hours hypothermic preservation in University of Wisconsin solution. The recipients were randomized into 2 groups: control pigs received isotonic saline and the treated group received the selective ET(A)-RA BSF 208075 at the beginning of reperfusion. On postoperative days 2 and 5, animals were relaparotomized to obtain tissue specimens. Blood monitoring included lipase, amylase, C-reactive protein, trypsinogen-activation peptide, thiobarbituric acid-reacting substances, and ET-1. Partial oxygen tension (p(ti)O(2)) was measured by a Clarke-type electrode and blood flow by laser doppler. A semiquantitative score index was used for assessment of histologic injury and for immunohistochemical analysis of ET-1 and ET(A) receptor expression. Tissue mRNA levels of prepro ET-1, ET(A) receptor, pro-interleukin (IL)-6, and pro-IL-1beta were quantified using TaqMan real-time reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

Prophylactic treatment with ET(A)-RA significantly reduced the severity of graft pancreatitis evidenced by C-reactive protein. The finding of transient capillary perfusion at the beginning of reperfusion supports the application of the ET(A)-RA during this period. The dramatic increase of plasma ET-1 in the therapy group is a clear evidence of effective receptor blockade. Mean trypsinogen-activation peptide levels from the portal venous effluent, but not mean systemic plasma TAP values were significantly lower in the treated group. Analysis of p(ti)O(2) and blood flow revealed a significant improvement of capillary perfusion and blood flow in the treated group and was associated with relevant reduction of tissue injury. Intrapancreatic ET-1 and IL-6 mRNA expression and ET-1 protein levels were significantly lower in the therapy group as compared with the control group. In contrast, ET(A) mRNA showed a marked up-regulation by ET(A) receptor blockade.

CONCLUSION

Application of a ET(A)-RA reduces ischemia/reperfusion induced graft pancreatitis in a pig transplantation model by improving microcirculation and reducing tissue injury.

Expression of IL-6 and integrin family cell adhesion molecules in acute necrotizing pancreatitis complicated with multiple organ injury in rats

AIM

To detect the expression of integrin family cellular adhesion molecules LFA-1, Mac-1 and IL-6 in acute necrotizing pancreatitis complicated with multiple organ injury.

METHODS

The flow cytometer was used to detect the expression of LFA-1 and Mac-1 on leukocyte and the radio-immunity to detect the IL-6 in acute necrotizing pancreatitis of rats at different time points.

RESULTS

The expression of LFA-1 and Mac-1 increased significantly in acute pancreatitis group compared with that in control group at all time points (P<0.01), i.e.: LFA-1: 1 h, 7.6±0.4 vs 22.7±1.6; 3 h, 7.9±0.5 vs 26.7±5.5; 6 h, 13.5±1.8 vs 30.3±1.6; 12 h, 9.7±0.7 vs 20.3±4.2; 24 h, 10.1±1.1 vs 15.9±0.7. Mac-1: 1 h, 6.2±1.1 vs 7.0±2.5; 3 h, 6.3±0.8 vs 36.0±1.5; 6 h, 7.9±1.2 vs 27.1±1.4; 12 h, 6.4±0.4 vs 22.5±2.1; 24 h, 7.1±0.4 vs 20.6±1.6. Expression of IL-6 increased significantly in acute pancreatitis group compared with that in control group, i.e.: 1 h, 65.6±3.2 vs 72.4±4.0 (P<0.05); 3 h, 68.2±5.5 vs 155.3±16.3 (P<0.01); 6 h, 69.3±2.6 vs 229.2±16.4 (P<0.01); 12 h, 73.4±2.6 vs 287.7±13.9 (P<0.01); 24 h, 76.9±3.3 vs 289.5±16.1 (P<0.01). Morphological examination demonstrated that inflammatory cells, insterstitial edema, interstitial hemorrhage, desquamation and disintegration occurred in the lungs and kidneys.

CONCLUSION

IL-6, LFA-1 and Mac-1 may play the very active role in acute pancreatitis.