This study aimed to determine the efficacy of low molecular weight heparin (LMWH) and lidocaine combined with LMWH for improving the course of acute pancreatitis (AP). A total of 30 rats were divided into three groups: the NaCl group, which received an intraarterial infusion of 0.9% sodium chloride; the Heparin group, which received a subcutaneous injection of LMWH; and the Lidocaine-Heparin group, which received an intraarterial infusion of 1% lidocaine, with subsequent subcutaneous injection of LMWH. AP was triggered using 80 μg/kg body weight of cerulein. Serum amylase and lipase levels were evaluated before induction of AP (measurement 0 - M0), after triggering AP (measurement 1 - M1), 1 h (measurement 2 - M2), 3 h (measurement 3 - M3), and 5 h (measurement 4 - M4) after treatment. After euthanasia, pancreatic tissues were collected for pathological analysis. No intergroup differences in serum amylase and lipase levels were observed between the NaCl and Heparin groups in all post-treatment evaluation points (M2, M3, and M4). Conversely, the Lidocaine-Heparin group showed significantly lower amylase values than the NaCl and Heparin groups in all post-treatment evaluation points. Furthermore, the Lidocaine-Heparin group showed significantly lower lipase values compared with the NaCl group in the first post-treatment evaluation point (M2), as well as compared with the Heparin group in the first (M2) and second (M3) post-treatment evaluation points. No significant intergroup differences were observed in pathological pancreatic tissue evaluation. Subcutaneous injection of LMWH did not impact the natural course of AP. However, the addition of intraarterially administered 1% lidocaine solution significantly reduced the severity of AP.

Emicizumab is used as hemostatic prophylaxis for patients with hemophilia A (PwHA), irrespective of the presence of inhibitors. Although bacterial infection can lead to a procoagulant state, there is limited information on coagulation and fibrinolysis potentials in emicizumab-treated PwHA and on the use of anticoagulants in such cases.

We examined whether anticoagulants affect the coagulation and fibrinolysis potentials in plasma from PwHA spiked with emicizumab.

Plasma from PwHA was in vitro supplemented with emicizumab (50 μg/mL; emi-plasma) and anticoagulants (recombinant thrombomodulin (rTM), nafamostat mesylate (NM), unfractionated heparin (UFH), or low-molecular-weight heparin (LMH)). PwHA plasma spiked with rFVIII (1 IU/mL) was used as a reference (ref-plasma). The coagulation and fibrinolysis potentials in plasma was measured by thrombin and plasmin generation assay (T/P-GA) and clot-fibrinolysis waveform analysis (CFWA).

In T/P-GA and CFWA, coagulation potentials (maximum coagulation velocity; |min1|, and peak thrombin; Th-Peak) in plasma rose with increasing concentrations of emicizumab and rFVIII, but fibrinolytic potentials (peak plasmin; Plm-Peak, and maximum fibrinolytic velocity; |FL-min1|) remained unchanged. Adding rTM, NM, and UFH to emi-plasma suppressed coagulation and fibrinolysis potentials, similar to ref-plasma. Regarding the heparin, UFH and LMH inhibited the improved coagulation in emi-plasma. UFH inhibited fibrinolysis as well, but LMH did not.

Anticoagulants could exhibit the inhibitory effects on the coagulation and fibrinolysis potentials in plasma from PwHA spiked with emicizumab, similar to those in normal plasma.

Acute pancreatitis (AP) involves sudden inflammation caused by abnormal activation of pancreatic enzymes. The mechanisms underlying AP include oxidative stress, high levels of inflammatory mediators and inflammatory cell infiltration. Heparin, a key therapeutic drug, exerts anti-inflammatory, antioxidative, and anticoagulative effects. However, safe and effective drug delivery remains an obstacle. This study is the first to investigate the therapeutic effects of heparin-loaded microbubbles (HPMB) combined with ultrasound (UHPMB) and the role of heparin in acoustic cavitation.

The characteristics of the microbubbles, including particle size, concentration, release, stability, and development, were studied. Heparin concentration in the HPMB was measured, and heparin-induced anticoagulation was evaluated. Drug safety was explored using hemolysis and cell viability assessments. The ability of HPMB to alleviate oxidative stress and inflammation were investigated in vitro. L-arginine induces AP in vivo. UHPMB was used for AP treatment. Serum amylase levels were measured and pancreatic architecture and pathological features were evaluated to determine AP severity. In vivo efficacy was evaluated, and the underlying mechanism of heparin action during acoustic cavitation was explored.

HPMB was spherical and presented as an emulsion-like solution without aggregation. HPMB was visible and stable and effectively released the drug under ultrasound (US). HPMB and UHPMB led to lower AP severity than in the untreated group. US-targeted microbubble destruction (UTMD) enhanced the therapeutic effect by decreasing oxidative stress and inflammation in AP models without injuring vital organs. UHPMB regulated VEGF/Flt-1 and SOD-1 expression. HPMB can also mitigate oxidative stress and inflammation in H₂O₂-pretreated cells.

UHPMB exhibits a strong ability not only to selectively target pancreatic lesions and release heparin but also to provide efficient protection by inhibiting oxidative stress and inflammation.

Pancreatitis, the inflammatory disorder of the pancreas, has no specific therapy. Genetic, biochemical, and animal model studies revealed that trypsin plays a central role in the onset and progression of pancreatitis. Here, we performed biochemical and preclinical mouse experiments to offer proof of concept that orally administered dabigatran etexilate can inhibit pancreatic trypsins and shows therapeutic efficacy in trypsin-dependent pancreatitis. We found that dabigatran competitively inhibited all human and mouse trypsin isoforms (Ki range 10-79 nM) and dabigatran plasma concentrations in mice given oral dabigatran etexilate well exceeded the Ki of trypsin inhibition. In the T7K24R trypsinogen mutant mouse model, a single oral gavage of dabigatran etexilate was effective against cerulein-induced progressive pancreatitis, with a high degree of histological normalization. In contrast, spontaneous pancreatitis in T7D23A mice, which carry a more aggressive trypsinogen mutation, was not ameliorated by dabigatran etexilate, given either as daily gavages or by mixing it with solid chow. Taken together, our observations showed that benzamidine derivatives such as dabigatran are potent trypsin inhibitors and show therapeutic activity against trypsin-dependent pancreatitis in T7K24R mice. Lack of efficacy in T7D23A mice is probably related to the more severe pathology and insufficient drug concentrations in the pancreas.

Aggressive intravenous fluid hydration, by administering 3500 mL of lactated Ringer's solution (LRS) in 9 h with a peri-procedural bolus, reduces post-ERCP pancreatitis (PEP) incidence. A concern of this strategy is adverse events related to volume overload; however, the impact of fluid hydration over an extended period without a bolus on PEP is unknown.

To assess the effect of continuous infusion of high-volume fluid at a constant rate over 24 h on PEP incidence and severity.

Two-hundred patients were randomly assigned (1:1) to receive either 3600 mL of LRS in 24 h starting 2 h before the ERCP (high-volume group) or maintenance fluid hydration calculated by the Holliday-Segar method (control group).

The mean age of the patients was 50.6 ± 11.6 years. The predominant indications were choledocholithiasis (48%) and malignancies (32%). Patient demographics and PEP risk factors were similar in both groups. Patients in the high-volume group received significantly more fluid than the control group (3600 vs. 2413 ml, P < 0.001). PEP incidence was not different between the high-volume and the control group (14% vs. 15%; relative risk 0.93: 95% CI 0.48-1.83, P = 0.84). There were no differences in moderate to severe PEP (3% vs. 4%; relative risk 0.75: 95% CI, 0.17-3.27, P = 1.00). Subgroup analysis did not show a benefit in high-risk patients. Only one patient in the control group developed peripheral edema.

An infusion of high-volume hydration over 24 h is not sufficient to provide optimal hydration for PEP prevention.

No. NCT02821546.

Acute pancreatitis is a potentially severe inflammatory disease that may be associated with a substantial morbidity and mortality. Currently there is no specific treatment for the disease, which indicates an ongoing demand for research into its pathogenesis and development of new therapeutic strategies. Due to the unpredictable course of acute pancreatitis and relatively concealed anatomical site in the retro-peritoneum, research on the human pancreas remains challenging. As a result, for over the last 100 years studies on the pathogenesis of this disease have heavily relied on animal models. This review aims to summarize different animal models of acute pancreatitis from the past to present and discuss their main characteristics and applications. It identifies key studies that have enhanced our current understanding of the pathogenesis of acute pancreatitis and highlights the instrumental role of animal models in translational research for developing novel therapies.

Coronavirus disease 2019 (COVID-19), the clinical syndrome associated with infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has impacted nearly every country in the world. Despite an unprecedented focus of scientific investigation, there is a paucity of evidence-based pharmacotherapies against this disease. Because of this lack of data-driven treatment strategies, broad variations in practice patterns have emerged. Observed hypercoagulability in patients with COVID-19 has created debate within the critical care community on the therapeutic utility of heparin. We seek to provide an overview of the data supporting the therapeutic use of heparin, both unfractionated and low molecular weight, as an anticoagulant for the treatment of SARS-CoV-2 infection. Additionally, we review preclinical evidence establishing biological plausibility for heparin and synthetic heparin-like drugs as therapies for COVID-19 through antiviral and anti-inflammatory effects. Finally, we discuss known adverse effects and theoretical off-target effects that may temper enthusiasm for the adoption of heparin as a therapy in COVID-19 without confirmatory prospective randomized controlled trials. Despite previous failures of anticoagulants in critical illness, plausibility of heparin for COVID-19 is sufficiently robust to justify urgent randomized controlled trials to determine the safety and effectiveness of this therapy.

The present study was aimed to explore the effects and the underlying mechanism of prophylactic low-molecular-weight heparin (LMWH) treatment on taurocholate-induced severe acute pancreatitis (SAP) in a rat model.

Rat SAP model was induced by injection of 4% sodium taurocholate into the pancreatic duct. LMWH was applied half an hour before the induction of pancreatitis at the dose of 200 IU/kg subcutaneous injection. The rats were euthanized at 1 h, 6 h, and 12 h after taurocholate-induced SAP. The inflammatory and oxidative response markers were assessed. And the vascular endothelial growth factor (VEGF) and Fms-related tyrosine kinase 1 (Flt-1) expression were evaluated by immunohistochemistry (IHC) and western blot methods.

The expression of inflammatory and oxidative response markers increased after induction of SAP. IHC and western blot results showed the VEGF and Flt-1 expression were increased in SAP group. Prophylactic LMWH administration reduced the inflammatory and oxidative response markers expression and decreased the expression of VEGF and Flt-1.

This study suggested that prophylactic LMWH treatment mitigated the severity of pancreatitis in rat SAP model by anti-inflammation and oxidative response. The underlying mechanism may result from downregulating VEGF/Flt-1 signaling of LMWH in SAP rat model.

Previous studies have suggested that aggressive hydration with lactated ringer solution are one of the protective factors in preventing post endoscopic retrograde cholangiopancreatography (post-ERCP). We conducted a systematic review and meta-analysis to examine the efficacy aggressive hydration with lactated Ringer solution in preventing PEP.

All published and unpublished articles on aggressive hydration with lactated ringer solution in those underwent ERCP procedure for any reasons were screened for eligibility. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. This paper doesn't need the IRB approval.

Seven RCTs met the inclusion criteria. Meta-analysis indicates that aggressive hydration with lactated Ringer solution were associated with lower PEP rate.[odds ratio (OR) 0.29; 95% confidence interval (CI) 0.18-0.48]; lower incidence of hyperamylasemia (OR 0.49; 95% CI 0.35, 0.69) and lower risk of pain (OR 0.28; 95% CI 0.10-0.81). The association between aggressive hydration with lactated Ringer solution and incidence of moderate severity PEP were unclear (OR 0.57; 95% CI 0.22, 1.45). Sensitivity analyses also showed that omitting 1 study from analysis of PEP rate could reduce the heterogeneity but did not change the conclusion of this meta-analysis. A cumulating meta-analysis was performed statistically which showed a stable result of overall incidence of PEP.

Aggressive hydration with lactated Ringer solution was a protective factor in reducing the overall incidence of PEP, hyperamylasemia and risk of abdominal pain.

Periprocedural intravenous hydration is suggested to decrease the risk of post-ERCP pancreatitis (PEP). However, quality of evidence supporting this suggestion remains poor. Here we hypothesized that aggressive hydration(AH) could be an effective preventive measure.

Pubmed, EMBASE, CINAHL, Google Scholar, Clinical Trials. gov, Clinical Key, International Standard Randomized Trial Number registry as well as secondary sources were searched through January 2019 to identify randomized controlled studies comparing AH to standard hydration (SH) for prevention of PEP. Pooled odds ratio (OR) and 95% confidence intervals (CIs) were calculated using the random-effects model. RevMan 5.3 was used for analysis.

A total of 9 RCTs, with 2094 patients, were included in the meta-analysis. AH reduced incidence of PEP by 56% compared to SH (OR = 0.44, CI:0.28-0.69; p = 0.0004). The incidence of post-ERCP hyperamylasemia also decreased with AH compared to SH (OR = 0.51; p = 0.001). Length of stay decreased by 1 day with AH (Mean Difference (MD): -0.89 d; p = 0.00002). There was no significant difference in adverse events related to fluid overload between two groups (OR:1.29; p = 0.81) and post-ERCP abdominal pain (OR:0.35; p = 0.17). Numbers of patient to be treated with AH to prevent one episode of PEP was 17. Final results of the meta-analysis were not affected by alternative effect measures or statistical models of heterogeneity.

Aggressive hydration is associated with a significantly lower incidence of PEP and it appears to be an effective and safe strategy for the prevention of Post ERCP pancreatitis.

Acute pancreatitis may be associated with both local and systemic complications. Systemic injury manifests in the form of organ failure, which is seen in approximately 20% of all cases of acute pancreatitis and defines "severe acute pancreatitis." Organ failure typically develops early in the course of acute pancreatitis, but also may develop later due to infected pancreatic necrosis-induced sepsis. Organ failure is the most important determinant of outcome in acute pancreatitis. We review here the current understanding of the risk factors, pathophysiology, timing, impact on outcome, and therapy of organ failure in acute pancreatitis. As we discuss the pathophysiology of severe systemic injury, the distinctions between markers and mediators of severity are highlighted based on evidence supporting their causality in organ failure. Emphasis is placed on clinically relevant end points of organ failure and the mechanisms underlying the pathophysiological perturbations, which offer insight into potential therapeutic targets to treat.

The pancreatic islets are more richly vascularized than the exocrine pancreas, and possess a 5- to 10-fold higher basal and stimulated blood flow, which is separately regulated. This is reflected in the vascular anatomy of the pancreas where islets have separate arterioles. There is also an insulo-acinar portal system, where numerous venules connect each islet to the acinar capillaries. Both islets and acini possess strong metabolic regulation of their blood perfusion. Of particular importance, especially in the islets, is adenosine and ATP/ADP. Basal and stimulated blood flow is modified by local endothelial mediators, the nervous system as well as gastrointestinal hormones. Normally the responses to the nervous system, especially the parasympathetic and sympathetic nerves, are fairly similar in endocrine and exocrine parts. The islets seem to be more sensitive to the effects of endothelial mediators, especially nitric oxide, which is a permissive factor to maintain the high basal islet blood flow. The gastrointestinal hormones with pancreatic effects mainly influence the exocrine pancreatic blood flow, whereas islets are less affected. A notable exception is incretin hormones and adipokines, which preferentially affect islet vasculature. Islet hormones can influence both exocrine and endocrine blood vessels, and these complex effects are discussed. Secondary changes in pancreatic and islet blood flow occur during several conditions. To what extent changes in blood perfusion may affect the pathogenesis of pancreatic diseases is discussed. Both type 2 diabetes mellitus and acute pancreatitis are conditions where we think there is evidence that blood flow may contribute to disease manifestations. © 2019 American Physiological Society. Compr Physiol 9:799-837, 2019.

Pancreatitis is the most common complication of endoscopic retrograde cholangiopancreatography (ERCP). The results of previous studies evaluating aggressive hydration with lactated Ringer solution for reducing the incidence of post-ERCP pancreatitis (PEP) are inconsistent.

We performed a meta-analysis to determine whether aggressive hydration with lactated Ringer solution reduced PEP.

Randomized controlled trials (RCTs) comparing aggressive hydration with standard hydration with the same lactated Ringer solution for prophylaxis of PEP were searched in PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and CINAHL databases. ClinicalTrial.gov and International Standard Randomised Controlled Trial Number registry were also searched for unpublished studies. A meta-analysis was conducted in accordance with the Cochrane Handbook for Systemic Reviews of Intervention.

A total of 7 RCTs with 1047 participants were included into this meta-analysis. Meta-analysis showed that aggressive hydration reduced the incidence of PEP as compared with standard hydration [odds ratio (OR), 0.47; 95% confidence interval (CI), 0.30-0.72; P=0.0006]. Aggressive hydration also reduced the incidence of post-ERCP hyperamylasemia as compared with standard hydration (OR, 0.38; 95% CI, 0.25-0.59; P<0.00001). No difference of adverse effects was found between aggressive hydration and standard hydration (OR, 0.48; 95% CI, 0.15-1.57; P=0.23). Sensitivity analyses showed that neither alternative effect measures nor statistical models regarding heterogeneity affected the conclusions of this meta-analysis. Sensitivity analyses also showed that omitting 1 study from analysis did not change the conclusion of this meta-analysis.

On the basis of this meta-analysis of RCTs, aggressive hydration with lactated Ringer solution is an effective and safe therapy for prophylaxis of PEP.

Acute pancreatitis (AP) is an inflammatory disease with varied severity, ranging from mild local inflammation to severe systemic involvement resulting in substantial mortality. Early pathologic events in AP, both local and systemic, are associated with vascular derangements, including endothelial activation and injury, dysregulation of vasomotor tone, increased vascular permeability, increased leukocyte migration to tissues, and activation of coagulation. The purpose of the review was to summarize current evidence regarding the interplay between inflammation, coagulation and endothelial dysfunction in the early phase of AP. Practical aspects were emphasized: (1) we summarized available data on diagnostic usefulness of the markers of endothelial dysfunction and activated coagulation in early prediction of severe AP; (2) we reviewed in detail the results of experimental studies and clinical trials targeting coagulation-inflammation interactions in severe AP. Among laboratory tests, d-dimer and angiopoietin-2 measurements seem the most useful in early prediction of severe AP. Although most clinical trials evaluating anticoagulants in treatment of severe AP did not show benefits, they also did not show significantly increased bleeding risk. Promising results of human trials were published for low molecular weight heparin treatment. Several anticoagulants that proved beneficial in animal experiments are thus worth testing in patients.

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.

Acute pancreatitis (AP) is an inflammatory disorder of the pancreas encompassing a cascade of cellular and molecular events. It starts from premature activation of zymogens with the involvement of innate immune system to a potential systemic inflammatory response and multiple organ failure. Leukocytes are the major cell population that participate in the propagation of the disease. Current understanding of the course of AP is still far from complete, limiting treatment options mostly to conservative supportive care. Emerging evidence has pointed to modulation of the immune system for strategic therapeutic development, by mitigating the inflammatory response and severity of AP. In the current review, we have focused on the role of innate immunity in the condition and highlighted therapeutics targeting it for treatment of this challenging disease.

The current review has aimed to elaborate in-depth understanding of specific roles of innate immune cells, derived mediators and inflammatory pathways that are involved in AP. Summarizing the recent therapeutics and approaches applied experimentally that target immune responses to attenuate AP.

The current state of knowledge on AP, limitations of presently available therapeutic approaches and the promise of therapeutic implications of innate immune system in AP are discussed.

Administration of heparin or its derivatives has been proved to be beneficial in the treatment of severe acute pancreatitis (SAP). However, drugs administered by conventional intravenous way are difficult to reach the pancreatic tissue and may cause bleeding complications due to coagulation and microcirculatory disturbance following initiation of SAP. In this study, we aimed to assess the effects of low-molecular-weight heparin (LMWH) administered with continuous regional arterial infusion (CRAI) technique in a porcine model of SAP.

Following baseline measurements, 18 animals were divided into three groups: CRAI group (LMWH infused through placed arterial catheter), venous group (LMWH infused through central venous catheter), and SAP control group. We used retrograde intraductal infusion of sodium taurocholate to induce SAP. Global hemodynamic profiles, urine output, systemic oxygenation, and inflammatory and serum biochemical parameters of the animals were studied. At the end of the experiment, histological examination of pancreas, intestine, and lung was performed.

Continuous regional arterial infusion with LMWH remarkably stabilized hemodynamic profiles, improved systemic oxygenation and peripheral perfusion, alleviated histological injury of pancreas (especially for the necrosis scale), and downregulated inflammatory response when compared with the other two groups. Moreover, serum D-dimer level also decreased most significantly in the CRAI group (474 ± 144 vs. 664 ± 155 µg/L in the venous group and 945 ± 351 µg/L in the controls at the end), partly indicating ameliorated coagulation disorders in the study group. No bleeding complication was observed in the CRAI group, whereas two animals in the venous group presented gastrointestinal hemorrhage.

Continuous regional arterial infusion with LMWH exhibits strong therapeutic effects in the course of SAP with great safety. Human studies using this novel therapy are required to assess these potential benefits in the clinical setting.

One of the most frequent and serious complications of endoscopic retrograde cholangiopancreatography (ERCP) is acute pancreatitis. The aim of this study was to evaluate the preventive effect of low-dose heparin (unfractionated or low-molecular-weight heparin) on post-ERCP pancreatitis (PEP) and its side-effects by a systematic review and meta-analysis of clinical trials. Searching PubMed and EMBASE, up to August 2011, two independent reviewers systematically identified prospective clinical trials detecting the effect of prophylactic low-dose heparin on the incidence of PEP, severe PEP, and post-ERCP hemorrhage complications. Four clinical trials fulfilled our selection criteria, with three prospective randomized and one nonrandomized. A meta-analysis of these clinical trials was then performed. A total of 1438 patients were included. Meta-analysis of these trials indicated that there was no significant association between the use of heparin and the reduction of PEP [relative risk (RR) 0.67, 95% confidence interval (CI): 0.44-1.03, P=0.07] and severe PEP (RR 0.62, 95% CI: 0.15-2.60, P=0.51). However, low-dose heparin did not increase the incidence of post-ERCP hemorrhage complications (RR 0.84, 95% CI: 0.34-2.03, P=0.69). This meta-analysis did not demonstrate a statistically significant benefit of prophylactic heparin use for the prevention of post-ERCP pancreatitis. More multicenter trials involving a larger number of patients are needed to show a possible prevention effect of PEP from heparin and its related compounds.

Oxidative stress plays an important role in the pathogenesis of both acute and chronic pancreatitis. Although its impact is well investigated and has been studied clinically in chronic pancreatitis, it is less well defined for acute pancreatitis.

Pathophysiological aspects of oxidative stress in acute pancreatitis have shown that reactive oxidative species (ROS) participate in the inflammatory cascade, and mediate inflammatory cell adhesion and consecutive tissue damage. Furthermore, ROS are involved in the generation of pain as another important clinical feature of patients suffering from acute pancreatitis.

Despite sufficient basic and experimental knowledge and evidence, the step from bench to bedside has not been successfully performed. Only a limited number of clinical studies are available that can give convincing evidence for the use of antioxidants in the clinical setting of acute pancreatitis.

Future studies are required to evaluate potential benefits of antioxidative substances to attenuate the severity of acute pancreatitis. Special focus should be put on the aspect of pain generation and the progression from mild to severe acute pancreatitis in the clinical setting.

Acute pancreatitis (AP) is a multifactorial disorder not fully understood yet. In particular, the pathogenetic pathways promoting a severe life-threatening course of AP are the subject of ongoing investigations. P-selectin has been shown to play a central role in the complex pathophysiology in AP as well as various other inflammatory conditions.

P-selectin function in AP is reviewed with focus on its dual function as a mediator of leukocyte recruitment and cell adhesion, which implies the unique effect of linking both inflammation and coagulation, especially in the progression from mild to severe necrotizing AP. Potential therapeutic aspects are discussed with regard to the clinical situation.

A better understanding of the pathogenic role of P-selectin in AP and of the rationale for a therapeutic blockade.

P-selectin is a glycoprotein that mediates the adhesion of activated platelets and leukocytes to the vessel wall in various inflammatory conditions. Both pathophysiological steps are closely linked and play a key role in the course of severe AP. A treatment approach by inhibition of P-selectin could be of distinct interest as a therapeutic option in severe AP.

Calcitonin gene-related peptide (CGRP) is released from perivascular pancreatic nerves. It effects vasomotion and cytokine liberation in inflammatory processes, including acute pancreatitis (AP). Calcitonin gene-related peptide liberation is stimulated by capsaicin, a substance of red hot chili peppers. Aim of the study was to investigate the influence of exogenous capsaicin on experimental AP.

Acute pancreatitis was induced in rats by glycodeoxycholic acid and cerulein. Animals were divided into 4 groups: (1) severe AP, (2) severe AP+capsaicin, (3) control without AP, and (4) control+capsaicin. After 24 hours, survival, histology, and CGRP were evaluated (n=6/group). In additional animals, erythrocyte flow and leukocyte activation were evaluated by intravital microscopy 6 hours after AP induction (n=6/group).

In the control groups, all animals survived without histological alterations. Mortality in severe AP was 67%. Capsaicin reduced mortality to 16% (P<0.05). Acute pancreatitis animals developed pancreatic inflammation and necrosis, which was significantly less after capsaicin application. Intravital microscopy in severe AP showed reduced erythrocyte velocity and increased leukocyte adhesion, which was nearly normalized by capsaicin (P<0.01). Calcitonin gene-related peptide increased in both capsaicin groups, indicating endogenous CGRP liberation (P<0.01).

Capsaicin releases endogenous CGRP with improved pancreatic microcirculation and reduced inflammation in experimental AP. This underlines neuropeptide activity in the pathogenesis of AP.

It is unclear why pancreatitis progresses either to mild edematous disease or to severe necrotic disease. The aim of the study was to shed some light on this topic by investigating differences during the early stages of necrotic and edematous pancreatitis.

Piglets were randomized into two groups. Necrotic pancreatitis was induced with retrograde injection of 20% taurocholic acid (1 ml/kg), and edematous pancreatitis was induced with 0.9% NaCl (1 ml/kg). Central hemodynamics was measured, and pancreatic microcirculation was directly examined by intravital microscopy. Vascular permeability to proteins and albumin was measured by microdialysis. Apoptosis and claudins 2, 3, 4, 5, and 7 were analyzed from pancreatic tissue samples. Blood samples were taken for analysis of blood cell counts, blood gases, lipase, and amylase.

Hemodynamic changes were similar in both groups, whereas microcirculatory impairment was more pronounced in necrotic pancreatitis. Necrosis was associated only with necrotic pancreatitis. Apoptosis increased only in edematous pancreatitis. The number of blood neutrophils and monocytes increased and lymphocyte and platelet counts decreased in both groups. Necrotic pancreatitis was associated with increased permeability to albumin and proteins. Expression of claudins 3, 4, 5, and 7 was not changed during pacreatitis, but in acinar cells, membranous expression of claudin-2 increased in both groups.

The results show that acute edematous pancreatitis is characterized by induction of apoptosis, whereas full-blown pancreatitis is characterized by necrosis. Impaired vascular permeability to albumin and protein is related to the early phase of necrotic pancreatitis. Claudin-2 increases during acute necrotic and edematous pancreatitis and may be related to impaired permeability.

To evaluate the effects of localized irrigation with epinephrine saline after endoscopic retrograde cholangiopancreatography (ERCP).

One hundred and fourteen patients who underwent ERCP in our institute were treated with or without irrigation using epinephrine diluted in saline after ERCP to prevent post-ERCP pancreatitis. The serum amylase levels, white blood cell counts, and urine amylase levels were measured at 24 and 48 hours after ERCP.

The treatment resulted in improvements in all items. A univariate analysis of the explanatory variables between the treatment and untreated groups revealed the treatment to be effective, but not statistically significant. Gender and cannulation of the pancreatic duct were the only variables with significant partial regression coefficients in the multiple regression model with all explanatory variables (p=0.045). When a stratified analysis was conducted using gender as a moderator variable, the treatment became a significant preventive factor (p=0.038), and cannulation of the pancreatic duct was a significant risk factor (p=0.027) in female patients.

We suggest that irrigating with epinephrine saline into the papilla may be effective for preventing pancreatitis in female patients who received ERCP with cannulation of their pancreatic duct.

Acute pancreatitis is a common inflammatory disorder of the pancreas resulting in considerable morbidity and a mortality rate of approximately 5%. Although there are no pharmacologic treatments known to improve important outcomes, aggressive intravenous fluid resuscitation generally is recommended in all patients. However, few human investigations have been performed and several important questions have not been answered. For example, what is the optimal resuscitative fluid? Is there a role for colloid solutions? To what clinical marker should resuscitation be targeted? When is the best time to start such fluids and in which group of patients? This review describes the microcirculation of the pancreas and the pathophysiologic alterations caused by acute pancreatitis. Previous animal experiments are described, as are the limited human studies specifically addressing fluid resuscitation. Finally, current recommendations and goals for further investigation are highlighted. It is our hope that this review will stimulate interest in this often overlooked subject and lead to carefully designed human clinical trials using varying fluid solutions and rates, with an emphasis on patient monitoring and safety, in the near future.

Besides alcohol and gallstones, pancreatic ischemia can cause acute pancreatitis (AP). This entity should be considered when no other reasons can be defined. The aim of the current study was to define ischemic AP with its pathophysiologic, radiologic, and clinical conditions.

Eleven patients with ischemic AP of different origin were analyzed regarding course, severity, and outcome, as well as diagnostic and therapeutic measures.

Ischemic AP was caused by hemorrhage and hypotension (7 patients) or mesenteric macrovessel occlusion (4 patients). Therapy was conservative (4 patients) or operative with hemostasis, necrosectomy, and drainage (7 patients). Seven patients died within 38 days, and 4 patients recovered.

Pancreatic hypoperfusion is an important etiology of AP. Severity of the disease ranges from moderate reversible changes to severe courses with fatal outcome. The indication for surgical intervention in ischemic AP is more aggressive; diagnostic and conservative therapeutic procedures are similar to AP of other etiologies.

This article aims to determine the effect of acute pancreatitis on microvascular morphology and the impact of treatment with hyperbaric oxygen (HBO).

Sixty-seven male Wistar rats were induced with acute pancreatitis by retrograde bile duct injection. Rats were randomized to 12-hourly HBO or control treatment. Two rats in each group were killed at baseline and 24, 48, and 72 hours postinduction, and a cast of the pancreatic microvasculature was examined using scanning electron microscopy.

Normal pancreatic vasculature is a dense network with a consistent capillary diameter. In acute pancreatitis, mean capillary diameter is increased at 24 hours (P < 0.001) and further increased at 48 hours (P = 0.007). From 24 hours, diameter heterogeneity is increased (P < 0.001) and capillary density is reduced (P < 0.001). Hyperbaric oxygen has a significant effect on vascular morphology changes from 48 hours after induction. Capillary diameter and heterogeneity of diameter are decreased by HBO (both P < 0.001). Capillary density is increased by HBO at 48 and 72 hours (P < 0.001).

In acute pancreatitis, structural capillary diameter and heterogeneity of diameter increase and capillary density decreases. These parameters are all improved by HBO treatment. Hyperbaric oxygen treatment normalizes the pancreatic microvasculature after acute pancreatitis and may be a potentially effective treatment of this disease.

Although there are various experimental pancreatic models in animals, only a few studies have evaluated how intraductal pressure and contrast agent affect the development of pancreatitis after endoscopic retrograde cholangiopancreatograpy (ERCP).

The rats were randomly divided into seven groups (n = 8/group). The rats in all groups underwent laparotomy and their biliopancreatic ducts were cannulated transduodenally using a 24G catheter. In the control group, group 1, the biliopancreatic ducts of the rats were not infused with any fluid. The biliopancreatic ducts of the rats in groups 2, 3, and 4 were infused with 0.5 ml isotonic NaCl solution at 10, 2, and 50 mmHg, respectively. Groups 5, 6, and 7 were given 0.5 ml of 50% diluted contrast agent at 10, 25, and 50 mmHg, respectively. The serum amylase, aspartate aminotransferase (AST), lactic dehydrogenase (LDH), and C-reactive protein (CRP) were measured 24 h after the procedure. Pancreatic tissue was also evaluated histopathologically.

Pancreatitis due to the contrast agent was noted when comparing the low pressure isotonic NaCl group and the low pressure contrast group (p < 0.05). Based on serum amylase and CRP values, there was a positive correlation between the severity and frequency of acute pancreatitis and pressure (p < 0.01). AST and LDH levels increased in all of the groups that underwent the procedure; however, no correlation was detected with increasing pressure or with the use of contrast agent (p > 0.05). Both pancreatic edema and the inflammatory cell infiltration score were elevated in isotonic NaCl and contrast group (p < 0.05); however, necrosis was not significantly changed (p > 0.05).

The results of this study suggest that the main mechanism for preventing pancreatitis after ERCP is to minimize trauma to the pancreatic canal, to cannulate the pancreas only when it is necessary, and to give contrast agent under low pressure when it is needed.

Acute pancreatitis generates a complex cascade of immunological events that affect the pathogenesis and the progression of this disease. Several inflammatory mediators seem to play a critical role in the pathogenesis of pancreatitis and the subsequent inflammatory response. In turn, these mediators can influence hemostasis. Coagulation abnormalities occur in acute pancreatitis and are related to its severity. The contribution of blood platelets in the disturbed hemostasis in acute pancreatitis, although extensively studied, remains obscure. This article reviews the local and systemic implications of hemostatic abnormalities during acute pancreatitis. Furthermore, we discuss the prognostic value and the potential therapeutic implications of platelet activation and other hemostatic variables.

To determine the effects of prophylactic peroxi-some proliferator-activated receptor (PPARgamma) agonist administration in an experimental model of post-endoscopic retrograde cholangiopancreatography (post-ERCP) acute pancreatitis.

Post-ERCP pancreatitis was induced in male Wistar rats by infusion of contrast medium into the pancreatic duct. In additional group, rosiglitazone, a PPARgamma agonist, was administered 1 h before infusion of contrast medium. Plasma and pancreas samples were obtained 6 h after the infusion.

Infusion of contrast medium into the pan-creatic duct resulted in an inflammatory process characterized by increased lipase levels in plasma, and edema and myeloperoxidase activity (MPO) in pancreas. This result correlated with the activation of nuclear factor kappaB (NFkappaB) and the inducible NO synthase (iNOS) expression in pancreatic cells. Rosiglitazone reduced the increase in lipase and the level of edema and the increase in myeloperoxidase as well as the activation of NFkappaB and iNOS expression.

A single oral dose of rosiglitazone, given 1 h before post-ERCP pancreatitis induction is effective in reducing the severity of the subsequent inflammatory process. The protective effect of rosiglitazone was associated with NFkappaB inhibition and the blockage of leukocyte infiltration in pancreas.

To extract from the biomedical published reports, the effects of hyperbaric oxygen (HBO) on inflammatory disease, in particular acute pancreatitis.

This review will explain these effects and evaluate potential mechanisms of action of HBO in acute pancreatitis. A Medline/PubMed search (January 1966 to July 2004) with manual cross-referencing was conducted, including all relevant articles investigating the molecular and systemic effects of HBO on inflammatory diseases, particularly focusing on the studies of acute pancreatitis. All publication types, languages and subsets were searched.

Original and review articles and short communications were extracted. The selected original articles covered the molecular and systemic effects of HBO and the effects in inflammatory disease states. The major findings are that HBO can act as an anti-inflammatory agent and as an antimicrobial agent. Many of the effects of HBO would be beneficial in the treatment of acute severe pancreatitis. Work carried out to date in animal models of acute pancreatitis shows promising improvements in severity but studies are limited to date.

Acute pancreatitis impairs the pancreatic and systemic microcirculation and causes acute inflammation. These processes are potentially improved by HBO therapy.

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.

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.

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.

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

Ischemia reperfusion (I/R)-associated early graft pancreatitis is a major complication after pancreas transplantation. The influence of immunosuppressants on graft pancreatitis remains unclear. The aim of this study was to evaluate ciclosporin and tacrolimus in experimental pancreatic I/R.

Moderate pancreatitis was induced in rats by I/R injury. Animals were assigned to 4 groups: (1) control without I/R, (2) I/R without therapy, (3) I/R + ciclosporin, or (4) I/R + tacrolimus. After 24 hours, pancreatic damage was evaluated by amylase, endothelin 1, thromboxane A2, and histology. Additionally, microcirculation was evaluated 12 hours after reperfusion by intravital microscopy.

I/R significantly increased amylase compared with controls, with maximum levels after ciclosporin treatment. Histology showed comparable tissue injury in control and tacrolimus-treated animals. Ciclosporin-treated animals developed significantly (P < 0.05) more inflammation and necrosis compared with the other groups. Erythrocyte velocity evaluated by intravital microscopy was reduced in all animals after I/R. This was significantly pronounced after ciclosporin application. There was a significant increase of adherent leukocytes and platelets in ciclosporin-treated animals compared with both other groups.

Tacrolimus does not negatively influence I/R-induced pancreatitis, whereas ciclosporin aggravates pancreatic tissue damage after I/R. These effects should be evaluated in the clinical setting of pancreas transplantation.