Platelet activating factor antagonism reduces the systemic inflammatory response in a murine model of acute pancreatitis

Protectin D1 decreases pancreatitis severity in mice by inhibiting neutrophil extracellular trap formation

BACKGROUND

Docosahexaenoic acid-derived protectin D1 (PD1) was identified critical in the resolution of inflammation in vivo, where it modulates the innate immune response and stimulates resolution. Acute pancreatitis (AP) is characterized by local pancreatic inflammation with mild forms whereas systemic inflammation with severe forms. Herein we investigate the impact of PD1 in murine models of pancreatitis.

METHODS

Three independent AP models, which induced in male mice via intraperitoneal injection of caerulein, L-arginine or pancreatic duct ligation, were used to confirm the protective effect of PD1. Infiltrationsof neutrophils and macrophages in pancreas were detected by flow cytometry and immunohistochemistry. In vitro and in vivo neutrophil extracellular traps formation was detected by immunofluorescence staining. Expression of peptidylarginine deiminase 4 (PAD4) in activated neutrophils was evaluated by western blotting.

RESULTS

Systemic treatment with PD1 reduced serum activities of amylase and lipase, blunted the concentrations of tumor necrosis factor-α and interleukin-6 in serum and protected against pancreas histologic damage in three AP models. PD1 also prolonged the survival in the pancreatic duct ligation model. Moreover, pancreatic infiltrationofneutrophils and neutrophil CitH3 expression were reduced after PD1 administration. In vitro studies revealed PD1 decreased supernatant cell-free DNA and CitH3 levels and downregulated PAD4 expression in mouse bone-marrow derived neutrophils. However, in the caerulein mice pretreated with GSK484 hydrochloride, an inhibitor of PAD4, PD1 treatment showed no more protective effect.

CONCLUSIONS

PD1 ameliorates AP by decreasing early infiltration of neutrophils into the pancreas and neutrophil extracellular traps formation through PAD4. These results supply the foundation to consider PD1 as a therapy for AP.

Protective and therapeutic effects of Danhong injection on acute pancreatitis‑associated lung injury

Lung functional impairment caused by acute pancreatitis (AP) is the primary contributor to AP‑associated mortality. Previous studies have reported that AP‑associated lung injury is associated with systemic inflammatory response syndrome and oxidative stress. In the present study, the protective effects of Danhong injection (DHI), a widely used Chinese Traditional Medicine preparation, on AP‑associated lung injury in rats was examined. The myeloperoxidase activity, malondiadelhyde level and superoxide dismutase activity determination demonstrated the anti‑inflammatory and anti‑oxidative properties of DHI. The results of western blotting and reverse‑transcription‑semi‑quantitative polymerase chain reaction indicated that DHI could protect rats against AP‑associated lung injury, and the protective effect was associated with the suppression of nuclear factor‑κB activation and cell adhesion molecule expression, and the reduction of neutrophil infiltration and oxidative stress levels. As demonstrated by HE staining, DHI inhibited the pancreas and lung tissue injury. Therefore, DHI could be a potential candidate for the treatment of patients with AP‑associated lung injury.

Hydroxyethyl starch resuscitation downregulate pro-inflammatory cytokines in the early phase of severe acute pancreatitis: A retrospective study

In the present study, we investigated the effects of hydroxyethyl starch (HES) 130/0.4 on serum pro-inflammatory variables, immunologic variables, fluid balance (FB)-negative(-) rate and renal function in severe acute pancreatitis (SAP) patients. From October, 2007 to November, 2008, a total of 120 SAP patients were enrolled in this retrospective study. Fifty-nine patients in the HES group received 6% HES 130/0.4 combined with crystalloid solution for fluid resuscitation (HES group). In the control group, 61 patients received only crystalloid solution after admission. Interleukin (IL)-1, IL-6, IL-8 and tumor necrosis factor (TNF)-α levels in serum were measured on days 1, 2, 4 and 8. The peripheral blood CD4+CD8+ T lymphocyte rates, serum BUN and Cr values were also measured on days 1, 4 and 8. Patients with FB(-) rates were recorded from day 1 to 8. Interaction term analysis (hospital stay and fluid resuscitation methods) based on mixed-effects regression model revealed significantly lower levels of IL-1 and TNF-α in the HES group compared with the control group. The difference in curve's risk ratio was not significant for IL-6, CD4+CD8+ T lymphocyte rate, BUN and Cr values (P>0.05). In the HES group, we detected a significantly higher rate of patients with FB(-) from day 4 to 8 (P<0.05). Thus, HES 130/0.4 resuscitation could decrease the IL-1 and IL-8 levels, shorten the duration of positive FB, and preserve the patient's immune status as well as renal function during the early phase of SAP.

Pharmacologic therapy for acute pancreatitis

While conservative management such as fluid, bowel rest, and antibiotics is the mainstay of current acute pancreatitis management, there is a lot of promise in pharmacologic therapies that target various aspects of the pathogenesis of pancreatitis. Extensive review of preclinical studies, which include assessment of therapies such as anti-secretory agents, protease inhibitors, anti-inflammatory agents, and anti-oxidants are discussed. Many of these studies have shown therapeutic benefit and improved survival in experimental models. Based on available preclinical studies, we discuss potential novel targeted pharmacologic approaches that may offer promise in the treatment of acute pancreatitis. To date a variety of clinical studies have assessed the translational potential of animal model effective experimental therapies and have shown either failure or mixed results in human studies. Despite these discouraging clinical studies, there is a great clinical need and there exist several preclinical effective therapies that await investigation in patients. Better understanding of acute pancreatitis pathophysiology and lessons learned from past clinical studies are likely to offer a great foundation upon which to expand future therapies in acute pancreatitis.

2',4',6'-Tris(methoxymethoxy) chalcone (TMMC) attenuates the severity of cerulein-induced acute pancreatitis and associated lung injury

Acute pancreatitis (AP) is an inflammatory disease involving acinar cell injury and rapid production and release of inflammatory cytokines, which play a dominant role in local pancreatic inflammation and systemic complications. 2',4',6'-Tris (methoxymethoxy) chalcone (TMMC), a synthetic chalcone derivative, displays potent anti-inflammatory effects. Therefore, we aimed to investigate whether TMMC might affect the severity of AP and pancreatitis-associated lung injury in mice. We used the cerulein hyperstimulation model of AP. Severity of pancreatitis was determined in cerulein-injected mice by histological analysis and neutrophil sequestration. The pretreatment of mice with TMMC reduced the severity of AP and pancreatitis-associated lung injury and inhibited several biochemical parameters (activity of amylase, lipase, trypsin, trypsinogen, and myeloperoxidase and production of proinflammatory cytokines). In addition, TMMC inhibited pancreatic acinar cell death and production of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 by inhibiting NF-κB and extracellular signal-regulated protein kinase 1/2 (ERK1/2) activation. Neutralizing antibodies for TNF-α, IL-1β, and IL-6 inhibited cerulein-induced cell death in isolated pancreatic acinar cells. Moreover, pharmacological blockade of NF-κB/ERK1/2 reduced acinar cell death and production of TNF-α, IL-1β, and IL-6 in isolated pancreatic acinar cells. In addition, posttreatment of mice with TMMC showed reduced severity of AP and lung injury. Our results suggest that TMMC may reduce the complications associated with pancreatitis.

Melanocortin 4 receptor stimulation decreases pancreatitis severity in rats by activation of the cholinergic anti-inflammatory pathway

OBJECTIVE

Acute pancreatitis is an inflammatory condition that may lead to multisystemic organ failure. Melanocortin peptides have been successfully used in experimental models of organ failure and shock, and their protective effect occurs through the activation of a vagus nerve-mediated cholinergic anti-inflammatory pathway by acting at brain melanocortin 4 receptors. In the light of these observations, we studied the effects of the selective melanocortin 4 receptor agonist RO27-3225 in an experimental model of cerulein-induced pancreatitis.

DESIGN

Randomized experiment.

SETTING

Research laboratory at a university hospital.

SUBJECT

Experimental pancreatitis in rats.

INTERVENTIONS

Acute pancreatitis was induced in male Sprague-Dawley rats by intraperitoneal injections of cerulein (80 μg/kg, four injections at hourly intervals). Before pancreatitis induction, groups of animals were subjected to bilateral cervical vagotomy, pretreated with the nicotinic acetylcholine receptor antagonist chlorisondamine or the selective melanocortin 4 receptor antagonist HS024, or not pretreated. Thirty minutes after the first cerulein injection, rats were intraperitoneally treated with a nanomolar dose of RO27-3225 or vehicle. Some experimental groups were prepared for neural efferent activity recording along the vagus nerve starting 30 mins after treatment with RO27-3225 or vehicle, and for a 30-min period.

MEASUREMENTS AND MAIN RESULTS

Serum lipase and amylase activity, tumor necrosis factor-α and interleukin-6 expression, pancreatic myeloperoxidase activity, and histologic damage were evaluated; neural efferent activity of vagal fibers was also assessed. RO27-3225 reduced cerulein-induced serum lipase and amylase activity, blunted the expression of tumor necrosis factor-α and interleukin-6, abated the increase in pancreatic myeloperoxidase activity, and protected against histologic damage. Furthermore, RO27-3225 markedly increased neural efferent activity along the vagus nerve. Vagotomy, chlorisondamine, and HS024 abated these protective effects of RO27-3225.

CONCLUSIONS

Our data show that melanocortin 4 receptor agonists reduce pancreatitis severity through the activation of the cholinergic anti-inflammatory pathway. These findings could be of particular interest in the clinical setting.

Gardenia jasminoides protects against cerulein-induced acute pancreatitis

AIM: To investigate the effect of Gardenia jasminoides (GJ) on cerulein-induced acute pancreatitis (AP) in mice.

METHODS: C57BL/6 mice weighing 18-20 g were divided into three groups. (1) Normal saline-treated group, (2) treatment with GJ at a dose of 0.1 g/kg, (3) treatment with GJ at a dose of 1 g/kg. GJ was administered orally (n = 6 per group) for 1 wk. Three hours later, the mice were given an intraperitoneal injection of cerulein (50 μg/kg), a stable cholecystokinin (CCK) analogue, every hour for a total of 6 h as described previously. The mice were sacrificed at 6 h after completion of cerulein injections. Blood samples were obtained to determine serum amylase, lipase and cytokine levels. The pancreas was rapidly removed for morphologic examination and scoring. A portion of pancreas was stored at -70°C and prepared for the measurement of tissue myeloperoxidase (MPO) activity, an indicator of neutrophil sequestration, and for reverse-transcriptase PCR (RT-PCR) and real-time PCR measurements.

RESULTS: Treatment with GJ decreased significantly the severity of pancreatitis and pancreatitis-associated lung injury. Treatment with GJ attenuated the severity of AP compared with saline-treated mice, as shown by reduction in pancreatic edema, neutrophil infiltration, serum amylase and lipase levels, serum cytokine levels, and mRNA expression of multiple inflammatory mediators.

CONCLUSION: These results suggest that GJ attenuated the severity of AP as well as pancreatitis-associated lung injury.

A murine model of obesity implicates the adipokine milieu in the pathogenesis of severe acute pancreatitis

Obesity is clearly an independent risk factor for increased severity of acute pancreatitis (AP), although the mechanisms underlying this association are unknown. Adipokines (including leptin and adiponectin) are pleiotropic molecules produced by adipocytes that are important regulators of the inflammatory response. We hypothesized that the altered adipokine milieu observed in obesity contributes to the increased severity of pancreatitis. Lean (C57BL/6J), obese leptin-deficient (LepOb), and obese hyperleptinemic (LepDb) mice were subjected to AP by six hourly intraperitoneal injections of cerulein (50 microg/kg). Severity of AP was assessed by histology and by measuring pancreatic concentration of the proinflammatory cytokines IL-1beta and IL-6, the chemokine MCP-1, and the marker of neutrophil activation MPO. Both congenitally obese strains of mice developed significantly more severe AP than wild-type lean animals. Severity of AP was not solely related to adipose tissue volume: LepOb mice were heaviest; however, LepDb mice developed the most severe AP both histologically and biochemically. Circulating adiponectin concentrations inversely mirrored the severity of pancreatitis. These data demonstrate that congenitally obese mice develop more severe AP than lean animals when challenged by cerulein hyperstimulation and suggest that alteration of the adipokine milieu exacerbates the severity of AP in obesity.

Therapy for acute pancreatitis with platelet-activating factor receptor antagonists

Acute pancreatitis (AP) causes release of platelet-activating factor (PAF), which induces systemic effects that contribute to circulatory disturbances and multiple organ failure. PAF is a cell surface secretion of bioactive lipid, which could produce physiological and pathological effects by binding to its cell surface receptor called platelet-activating factor receptor (PAF-R). Studies showed that PAF participates in the occurrence and development of AP and administration of platelet-activating factor receptor antagonists (PAF-RAs) could significantly reduce local and systemic events after AP. PAF has also been implicated as a key mediator in the progression of severe AP, which can lead to complications and unacceptably high mortality rates. Several classes of PAF-RA show PAF-RAs significant local and systemic effects on reducing inflammatory changes. As a preventive treatment, PAF-RA could block a series of PAF-mediated inflammatory injury and thus improve the prognosis of AP. This review introduces the important role of PAF-RA in the treatment of AP.

Effects of bee venom on cholecystokinin octapeptide-induced acute pancreatitis in rats

OBJECTIVES

Bee venom (BV) has frequently been used as a remedy for inflammatory diseases. The aim of this study was to investigate the effect of BV on cholecystokinin octapeptide (CCK-8)-induced acute pancreatitis (AP) in rats.

METHODS

The BV pretreatment group: 0.25 mg/kg BV was administered subcutaneously, followed by 75 mug/kg CCK-8 subcutaneously 3 times after 1, 3, and 5 hours. This whole procedure was repeated for 5 days.

CONTROL GROUP

CCK-8 subcutaneously 3 times after 1, 3, and 5 hours for 5 days. The BV posttreatment group: CCK-8 subcutaneously 3 times at an interval of 2 hours for 3 days, and then 0.25 mg/kg of BV was administered subcutaneously.

CONTROL GROUP

CCK-8 subcutaneously 3 times at an interval of 2 hours for 3 days.

RESULTS

The BV pretreatment and posttreatment ameliorated many of the examined laboratory parameters (the pancreatic weight [PW]/body weight [BW] ratio, the serum amylase and lipase activity) and reduced histological damages in pancreas. Furthermore, BV pretreatment reduced the production of tumor necrosis factor-alpha, interleukin 1, and interleukin 6 and also decreased pancreatic nuclearfactor-kappaB binding activity compared with saline-treated group in the AP model. The BV also increased heat shock protein 60 (HSP60) and heat shock protein 72 (HSP72) compared with the saline-treated group in the AP model.

CONCLUSIONS

These findings suggest that the anti-inflammatory effect of BV in CCK-8-induced AP seems to be mediated by inhibiting nuclear factor-kappaB binding activity, and that BV may have a protective effect against AP.

Selective cyclooxygenase-2 inhibitor ameliorates cholecystokinin-octapeptide-induced acute pancreatitis in rats

AIM: To investigate the effect of selective Cycloo-xygenase-2 (COX-2) inhibitor 4-[5-(4-Chloro-phenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl] benzenesulfonamide (SC-236), on the cholecystokinin (CCK)-octapeptide-induced acute pancreatitis (AP) in rats.

METHODS: Wistar rat weighing 240 g to 260 g were divided into three groups. (1) Normal DMSO treated group, (2) SC-236 at 4 mg/kg treated group; SC-236 systemically administered via the intravenous (i.v.) catheter, followed by 75 μg/kg CCK octapeptide subcutaneously three times, after 1, 3 and 5 h. This whole procedure was repeated for 5 d. (3) Dimethyl sulfoxide (DMSO) treated group: an identical protocol was used in this group as in the SC-236 cohort (see 2. above). Repeated CCK octapeptide treatment resulted in a typical experimentally induced pancreatitis in the Wistar rats.

RESULTS: SC-236 improved the severity of CCK-octapeptide-induced AP as measured by laboratory criteria [the pancreatic weight/body weight (p.w/b.w) ratio, the level of serum amylase and lipase]. The SC-236 treated group showed minimal histologic evidence of pancreatitis and a significant reduction in myeloperoxidase activity. SC-236 also increased heat shock protein (HSP)-60 and HSP72 compared with the DMSO-treated group in the CCK-octapeptide-induced AP and also reduced the pancreatic levels of COX-2. Furthermore, SC-236 reduced proinflammatory cytokine synthesis and inhibited NF-κB activation compared with the DMSO-treated group in the CCK-octapeptide-induced AP.

CONCLUSION: Our results suggested that COX-2 plays pivotal role in the development of AP and COX-2 inhibitors may play a beneficial role in preventing AP.

Why does pancreatic overstimulation cause pancreatitis?

Many animal models are available to investigate the pathogenesis of pancreatitis, an inflammatory disorder of the pancreas. However, the secretagogue hyperstimulation model of pancreatitis is the most commonly used. Animals infused with high doses of cholecystokinin (CCK) exhibit hyperamylasemia, pancreatic edema, and acinar cell injury, which closely mimic pancreatitis in humans. Intra-acinar zymogen activation is an essential early event in the pathogenesis of secretagogue-induced pancreatitis. Early in the course of pancreatitis, lysosomal hydrolases colocalize with digestive zymogens and activate them. These activated zymogens then cause acinar cell injury and necrosis, a characteristic of pancreatitis. Besides being the site of initiation of injury in pancreatitis, acinar cells also synthesize and release cytokines and chemokines very early in the course of pancreatitis, which then attract and activate inflammatory cells and initiate the disease's systemic phase.

Acute pancreatitis: models, markers, and mediators

Acute pancreatitis has an incidence of approximately 40 cases per year per 100,000 adults. Although usually self-limiting, 10% to 20% of afflicted patients will progress to severe pancreatitis. The mortality rate among patients with severe pancreatitis may approach 30% when they progress to multisystem organ failure. The development of acute pancreatitis illustrates the requirement for understanding the basic mechanisms of disease progression to drive the exploration of therapeutic options. The pathogenesis of acute pancreatitis involves the interplay of local and systemic immune responses that are often difficult to characterize, particularly when results from animal models are used as a foundation for human trials. Experimental studies suggest that the prognosis for acute pancreatitis depends upon the degree of pancreatic necrosis and the intensity of multisystem organ failure generated by the systemic inflammatory response. This suggests an intricate balance between localized tissue damage with proinflammatory cytokine production and a systemic, anti-inflammatory response that restricts the inappropriate movement of proinflammatory agents into the circulation. The critical players of this interaction include the proinflammatory cytokines IL-1beta, TNF-alpha, IL-6, IL-8, and platelet activating factor (PAF). The anti-inflammatory cytokines IL-10, as well as TNF-soluble receptors and IL-1 receptor antagonist, have also been shown to be intimately involved in the inflammatory response to acute pancreatitis. Other compounds implicated in disease pathogenesis in experimental models include complement, bradykinin, nitric oxide, reactive oxygen intermediates, substance P, and higher polyamines. Several of these mediators have been documented to be present at increased concentrations in the plasma of patients with severe, acute pancreatitis. Preclinical work has shown that some of these mediators are markers for disease activity, whereas other inflammatory components may actually drive the disease process as important mediators. Implication of such mediators suggests that interruption or blunting of an inappropriate immune response has the potential to improve outcome. Although the manipulations of specific mediators in animal models may be promising, they may not transition well to the human clinical setting. However, continued reliance on experimental animal models of acute pancreatitis may be necessary to determine the underlying causes of disease. Full understanding of these basic mechanisms involves determining not only which mediators are present, but also closely documenting the kinetics of their appearance. Measurement of the inflammatory response may also serve to identify diagnostic markers for the presence of acute pancreatitis and provide insight into prognosis. Understanding the models, documenting the markers, and deciphering the mediators have the potential to improve treatment of acute pancreatitis.

Effects of Chaishao Chengqi decoction with ginkgo biloba leaf on lung injury induced by severe acute pancreatitis

AIM: To explore the preventive and therapeutic effects of Chaishao Chengqi decoction (CCD) with ginkgo biloba leaf (GBL) on the lung injury induced by severe acute pancreatitis (SAP).

METHODS: A total of 65 SAP patients were divided into group A (n = 35) and B (n = 30). Besides internal treatment, the patients in group A also received CCD plus GBL. The occurrence of hypoxemia, duration of abdominal pain-relief, recovering time of borborygmus, local complications, and mortality rate as well as the level changes of serum platelet-activating factor (PAF), tumor necrosis factor-a (TNF-a), and interleukin-1 (IL-1) 72 h after treatment were observed, respectively. Upper abdominal spiral CT scanning was used to evaluate the degrees of severe acute pancreatitis.

RESULTS: The incidence rates of hypoxemia and acute respiratory distress syndrome were significantly lower group A than those in group B (45.71% vs 73.33%, P < 0.05; 8.57% vs 30%, P < 0.05). The serum levels of inflammatory factors dropped markedly in group A 72 h after treatment (PAF: 4.45 ± 1.25 → 2.83 ± 1.64 mg/L, P < 0.01; TNF-a: 32.96 ± 4.33 → 27.82 ± 5.26 ng/L, P < 0.01; IL-1: 3.46 ± 1.07 → 2.51 ± 0.52 ng/L, P < 0.01), but they had no changes in group B. The duration of abdominal pain-relief, recovering time of borborygmus and progressive proportion of pancreatic inflammation were decreased in group A as compared with those in group B (P < 0.05). The rates mortality and local complications were 0 and 2.86% in group A, and 10% and 13.33% in group B, respectively.

CONCLUSION: CCD plus GBL has preventive and therapeutic action on the SAP-induced lung injury, and the mechanism is probably related to its inhibition on the secretion of inflammatory mediators.

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Inhibitory effect of Patrinia scabiosaefolia on acute pancreatitis

AIM: To investigate the effect of Patrinia scabiosaefolia (PS) on the cholecystokinin (CCK) octapeptide- induced acute pancreatitis (AP) in rats.

METHODS: Wistar rats weighing 240-260 g were divided into three groups: (1) Normal saline-treated group; (2) treatment with PS at 100 mg/kg group, in which PS was administered orally, followed by subcutaneous administration of 75 µg/kg CCK octapeptide three times after 1, 3 and 5 h, and this whole procedure was repeated for 5 d; (3) treatment with saline group, in which the protocols were the same as in treatment group with PS. We determined the pancreatic weight/body weight ratio, the levels of pancreatic HSP60, HSP72 and the secretion of pro-inflammatory cytokines. Repeated CCK octapeptide treatment resulted in the typical laboratory findings of experimentally induced pancreatitis.

RESULTS: PS reduced the pancreatic weight/body weight ratio, the levels of serum amylase and lipase, and inhibited expressions of pro-inflammatory cytokines in the CCK octapeptide-induced AP. Furthermore, PS pretreatment increased the pancreatic levels of HSP60 and HSP72.

CONCLUSION: Pretreatment with PS has an anti-inflammatory effect on CCK octapeptide-induced AP.

Role of platelet-activating factor in pathogenesis of acute pancreatitis

Platelet-activating factor (PAF) is a potent proinflammatory phospholipid mediator that belongs to a family of biologically active, structurally related alkyl phosphoglycerides with diverse pathological and physiological effects. This bioactive phospholipid mediates processes as diverse as wound healing, physiological inflammation, angiogenesis, apoptosis, reproduction and long-term potentiation. PAF acts by binding to a specific G protein-coupled receptor to activate multiple intracellular signaling pathways. Since most cells both synthesize and release PAF and express PAF receptors, PAF has potent biological actions in a broad range of cell types and tissues. Inappropriate activation of this signaling pathway is associated with many diseases in which inflammation is thought to be one of the underlying features. Acute pancreatitis (AP) is a common inflammatory disease. The onset of AP is pancreatic autodigestion mediated by abnormal activation of pancreatic enzyme caused by multiple agents, which subsequently induce pancreatic and systemic inflammatory reactions. A number of experimental pancreatitis and clinical trials indicate that PAF does play a critical role in the pathogenesis of AP. Administration of PAF receptor antagonist can significantly reduce local and systemic events that occur in AP. This review focuses on the aspects that are more relevant to the pathogenesis of AP.

Pancreatic acinar cell: its role in acute pancreatitis

The pancreatic acinar cell is the functional unit of the exocrine pancreas. It synthesizes, stores, and secretes digestive enzymes. Under normal physiological conditions, digestive enzymes are activated only once they have reached the duodenum. Premature activation of these enzymes within pancreatic acinar cells leads to the onset of acute pancreatitis; it is the major clinical disorder associated with pancreatic acinar cells. Although there have been major advances in our understanding of the pathogenesis of this disease in recent years, available treatment options are still limited to traditional nonspecific and palliative interventions. Novel therapeutic strategies have been suggested based on ongoing research in the physiology and pathophysiology of the disease; these include the administration of systemic antibiotics, antioxidants, cytokine antagonists, and more recently, inhibition of the renin-angiotensin system. Notwithstanding this promising development, most of these potential therapies are still in an experimental stage or clinical trial. Further investigation is needed to prove the efficacy of these novel treatment modalities.

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Medical treatment of acute pancreatitis

Eighty percent of all cases of acute pancreatitis are linked etiologically to gallstone disease or caused by immoderate alcohol consumption. No specific causal treatment for acute pancreatitis exists. Early prognostic factors that indicate severe disease are three or more signs on organ failure scores according to Ranson, Imrie, or Acute Physiology and Chronic Health Evaluation (APACHE) 11, extrapancreatic complications of the disease, or the detection of pancreatic necrosis on CT scans. Elevated CRP levels above 130 mg/L can also predict a severe course of acute pancreatitis. The essential medical treatment for acute pancreatitis is the correction of hypovolemia. Moreover, relief of often severe visceral pain is a high priority. Prophylactic antibiotics should be restricted to patients with necrotizing pancreatitis, infected necrosis, or other infectious complications. Enteral nutrition has no adverse effect compared with parenteral nutrition during the course of acute pancreatitis, and is probably beneficial in regard to outcome.

Effects of molsidomine and lexipafant in hepatic ischaemia--reperfusion injury

PURPOSE

The purpose of this study was to evaluate the effects of nitric oxide donor molsidomine and platelet-activating factor (PAF) antagonist lexipafant on the hepatic IR injury in rats.

METHODS

Fifty male Sprague-Dawley rats (200-225 g) were divided into five groups each containing 10 rats; group SO: Sham operation group; group I: hepatic ischaemia group; group IR: ischaemia-reperfusion (IR); group M: IR plus pretreatment with molsidomine; group L: IR plus pretreatment with lexipafant. Hepatic ischaemia and reperfusion, each were applied for 45 min. Hepatic specimens were obtained to determine the tissue levels of malondialdehyde (MDA) and histological changes. Blood samples were obtained by cardiac puncture for determination of alanine transaminase (ALT), aspartate transaminase (AST) and lactic dehydrogenase (LDH).

RESULTS

The liver damage scores of groups I, IR, M and L were significantly higher than that of group SO (P < 0.001). The liver damage scores of groups IR and M were significantly higher than that of group I (P = 0.009 and 0.0035, respectively). The liver damage scores of groups M and L were significantly lower than that of group IR (P < 0.001 for both M and L). Mean MDA levels of groups I and IR were significantly higher than those of group SO (P < 0.001). Administrations of molsidomine and lexipafant prior to ischaemia-reperfusion (IR) resulted in significant reduction of the MDA values (P < 0.001). A statistically significant (P < 0.001) decrease in the levels of AST, ALT and LDH was observed in groups M and L compared with group IR.

CONCLUSION

In conclusion, these observations suggest that pre-treatment with nitric oxide donor molsidomine and PAF antagonist lexipafant before the reperfusion period may be useful in preventing hepatic reperfusion injury.

Influence of platelet activating factor on expression of adhesion molecules in experimental pancreatitis

AIM: To determine whether Platelet activating factor (PAF) has a regulation role in the expression of adhesion molecules and accumulation of neutrophils in a murine model of acute pancreatitis.

METHODS: One hundred twenty-eight Kunming mice were divided into four groups. Group 1 received 0.1 mL saline s.c. every hour for three hours (sham). Group 2 received cerulein (50 μg/kg dose s.c.) every hour for three hours. Group 3 received AP and additional challenge of PAF (50 mg/kg in absolute ethanol) (AP/PAF). Group 4 received AP, plus therapeutic treatment with GAB (25 mg dose i.p.) immediately after the first challenge of cerulein (AP/GAB). Animals were sacrificed at 12 h after the first challenge of saline or cerulein. Adhesion molecules of pancreas were semi-quantified by SP methods. Standard assays were performed for serum amylase and myeloperoxidase activity (MPO) of pancreas. Histology of pancreas was scored in a blind manner. Water content of pancreas was also measured at the same time.

RESULTS: Control pancreata showed negligible adhesion molecule expression and neutrophil accumulation. There were evident adhesion molecules expression and neutrophil accumulation in AP and AP/PAF compared with sham (P < 0.05). AP/GAB had a lower level of adhesion molecules, neutrophils, and water content versus AP and AP/PAF (P < 0.05). Histology showed a trend toward improvement in AP/GAB, but did not reach statistical significance.

CONCLUSION: PAF can induce the expression of adhesion molecules that mediate neutrophil accumulation. The PAF antagonist reduces the expression of adhesion molecules and the severity of inflammation when given immediately after the induction of mild AP in mice. These results suggest that PAF antagonism may be useful in the treatment of mild pancreatitis after its clinical onset.