Oxidative stress in acute pancreatitis.

The present work critically reviews the evidence for an involvement of free radicals in the pathophysiology of acute pancreatitis and the potential of treatment with antioxidants and scavenger substances. Data originating from clinical trials, experimental pancreatitis studies and in vitro investigations are included. Enhanced free radical activities and increased concentrations of lipid peroxides in plasma and tissue have been found in both patients and experimental animals with acute pancreatitis. The individual contribution of possible sources of free radicals (e.g., invading inflammatory cells, xanthine oxidase, cytochromes P450, nitric oxide synthase) is not yet clear, however. Since prophylactic administration of antioxidants diminished, in particular, pancreatic edema formation, free radicals seem to play an important role in the genesis of edema in acute pancreatitis. An involvement of free radicals in the pathogenesis of pancreatic necrosis could not yet be proven. Thus, no antioxidant treatment has proven useful for therapy of fulminant pancreatitis in animals to date. However, in severe acute pancreatitis characterized by death occurring after 12-18 hours, the seleno-organic compound Ebselen, which has a glutathione peroxidase-like activity, and the membrane permeable ascorbic acid derivative CV-3611 have been demonstrated to be effective. To date, controlled clinical studies have failed to demonstrate the therapeutic efficacy of antioxidant selenium or glutathione precursor supplementation. Therefore, further controlled clinical trials are needed to determine whether supplements of antioxidants can alter the clinical course of acute pancreatitis. Since the nitric oxide radical may even protect the pancreas, a purely negative discussion of the role of free radicals on the pancreas is not justified. The actual role of free radicals in acute pancreatitis, i.e. serving the body's defense against infection, being an epiphenomenon of the inflammatory process without pathophysiological relevance, or having true pathogenic significance, is not yet clear. Lipid peroxidation may perhaps not be the cause but rather the sequel of pancreatic inflammation and may likely reflect the severity of the systemic inflammatory response rather than that of pancreatic parenchyma damage. In vitro, exposure of isolated pancreatic acinar cells to oxidative stress caused rapid cell damage and death. Such knowledge from cellular studies might help to plan therapeutical trials to evaluate potentially effective therapies in the experimental animal, as well as in patients suffering from pancreatitis. Thus, to further clarify the role of oxidative stress in acute pancreatitis, an integrated approach is needed, including investigations at various biological levels, from isolated cells or even organelles to laboratory animals and, finally, clinical studies in man.

[The effect of chelidonium- and turmeric root extract on upper abdominal pain due to functional disorders of the biliary system. Results from a placebo-controlled double-blind study]. / Die Wirkung von Schöllkraut- und Curcumawurzelstock-Extrakt auf Oberbauchbeschwerden infolge funktioneller Störungen des ableitenden Gallensystems. Ergebnisse einer plazebokontrollierten Doppelblindstudie.

BACKGROUND: Right upper abdominal pain may often be caused by biliary dyskinesia. Choleretica and cholekinetica are widely used for medical treatment of complaints due to biliary dyskinesia despite of a lack of randomized clinical trials which may prove their efficacy and potency. PATIENTS AND METHODS: The present prospective multicenter pilot study analyzes the effects of Cholagogum F Nattermann (dried extracts from Schöllkraut and Curcuma) in comparison with placebo in patients with dumpy or colicky abdominal pain in the right upper quadrant due to biliary dyskinesia. Cholagogum was given in 39 patients and placebo in 37 patients for 3 weeks, respectively. RESULTS: The reduction of dumpy and colicky pain was more rapid during the first treatment week in patients who received Cholagogum F when compared to those who received placebo. The reduction of other complaints (feeling of being filled up, food intolerance, nausea, vomiting, meteorism) (secondary variables) was similar in patients who received Cholagogum F versus placebo during the whole treatment period. The were no side-effects in patients who received Cholagogum. CONCLUSIONS: The study presents the first solid indication that extracts from Schöllkraut/Curcuma (Cholagogum F Nattermann) which have widely been used in daily practice for many decades have beneficial effects on pain due to biliary dyskinesia.

-Cardiomyopathy as the cause of death in genetic hemochromatosis-. / Kardiomyopathie als Todesursache bei genetischer Hämochromatose.

Hemochromatosis is an autosomal-recessive disease which causes iron-overload of various organs including liver, pancreas and heart. This report analyzes the course of hemochromatosis in two patients (a 28-year-old man and a 57-year-old woman) in whom hemochromatosis was detected because of severe cardiomyopathy. Initial symptoms were edema, anasarca and dyspnea. Further examinations showed pleural effusion, decreased left-ventricular-function, skin pigmentation, diabetes mellitus and liver cirrhosis. Although phlebotomy treatment and iron-chelation therapy with deferoxamine initially resulted in some improvement, both patients died from cardiomyopathy three months after diagnosis. The reports of these two cases underline that hemochromatosis-associated cardiomyopathy is often irreversible if severe congestive heart failure is present. In cardiac decompensation heart transplantation has to be considered as early as possible.

Effects of C1-esterase inhibitor in three models of acute pancreatitis.

The present studies were done to evaluate the therapeutic potential of C1-esterase inhibitor in three different models of acute pancreatitis: (1) Edematous pancreatitis with acinar cell necrosis was induced by 7-h ip injections of 50 micrograms/kg cerulein in mice; (2) Hemorrhagic pancreatitis was induced by feeding a choline-deficient, ethionine-supplemented (CDE) diet in mice; and (3) Hemorrhagic pancreatitis was induced by retrograde infusion of 0.6 mL 5% sodium-taurocholate into the pancreatic duct in rats. C1-esterase inhibitor was given at 100 mg/kg iv before the onset of pancreatitis and at certain intervals thereafter. The severity of pancreatitis was assessed at various times after its onset by determination of serum amylase, by grading of histological alterations, and by determination of survival (survival determined only in models of hemorrhagic pancreatitis). In some of the models, C1-esterase inhibitor slightly ameliorated the degree of histological alterations; the increase in serum amylase was reduced by C1-esterase inhibitor only in CDE diet-induced pancreatitis. In all three models, C1-esterase inhibitor, however, failed to cause major beneficial effects and also failed to improve survival in taurocholate- and diet-induced pancreatitis. Additional studies in 12 patients with acute pancreatitis showed that C1-esterase inhibitor activity was markedly increased in serum of all patients during the first 9 d of the disease, suggesting that C1-esterase inhibitor behaves like an acute phase protein. Taken together the results from the animal and the human studies, C1-esterase inhibitor appears to only have a limited potential for treatment of acute pancreatitis.

Acute experimental hemorrhagic-necrotizing pancreatitis induced by feeding a choline-deficient, ethionine-supplemented diet. Methodology and standards.

The present work evaluates the methodology and standards of acute hemorrhagic-necrotizing pancreatitis induced by feeding a choline-deficient, ethionine-supplemented (CDE) diet to mice. The diet model appears to be a good approximation of severe necrotizing human pancreatitis. Both the gross and histological appearance of the pancreatic and peripancreatic inflammation as well as the clinical and biochemical course of diet-induced pancreatitis resemble human disease. By limiting the period of feeding the diet, one can control the mortality at any desired level between 0 and 100%. Ascites, acidosis, hypoxia and hypovolemia occur in this model as well as in human pancreatitis. The time course of the morphological and biochemical alterations have extensively been studied and are, thus, well defined in this model. Despite the differences in pathogenesis of pancreatitis induced in this model versus human disease, the experimental pancreatitis and clinical pancreatitis share several pathophysiologic features. Therefore, the model is suitable to study pathophysiologic aspects of this disease. The diet model is particularly well suitable to study the potential for new therapeutic substances. The small size of the animals used, however, is a limitation for the evaluation of surgical procedures and of new diagnostic tools. Several pitfalls and problems have to be considered in order to obtain valuable data. The amount of injury produced by the CDE diet depends critically on sex, age and weight of the mice. Special care has to be taken to guarantee that the intake of the CDE diet is identical between different experimental groups. Therefore, each set of experiments needs to include a separate control group of mice which receive the CDE diet without any other special treatment. The potential benefit of an experimental therapy can be assessed by measuring survival, various biochemical and histological features, and alterations in hematocrit, pH and blood gases.

Effects of antioxidants and free radical scavengers in three different models of acute pancreatitis.

The present studies were done to evaluate the therapeutic potential of several antioxidants and free radical scavengers in three different models of acute pancreatitis. (a) Edematous pancreatitis with acinar cells necrosis was induced by seven hourly intraperitoneal injections of 50 micrograms of caerulein per kg in mice. (b) Hemorrhagic pancreatitis was induced by feeding a choline-deficient, ethionine-supplemented (CDE) diet in mice. (c) Hemorrhagic pancreatitis was induced by retrograde infusion of 0.6 ml of 5% sodium taurocholate into the pancreatic duct in rats. The following antioxidants and free radical scavengers were given at various doses intravenously, subcutaneously, or intraperitoneally before the onset of pancreatitis: Ebselen [2-phenyl-1,2-benzisoselenazol-3(2H)-one], superoxide dismutase, catalase, deferoxamine (Desferal), dimethyl sulfoxide, or allopurinol. The severity of pancreatitis was assessed at various times after its onset by determination of serum amylase and pancreatic weight (edema), by grading of histological alterations, and by determination of survival (survival determined in models of hemorrhagic pancreatitis). In general, free radical scavengers and antioxidants ameliorated edema and inflammation to a greater degree than necrosis and the increase in serum amylase. Superoxide dismutase (as did Ebselen in previous studies) exerted beneficial effects on survival in diet-induced pancreatitis in the absence of marked effects on pancreatic necrosis, suggesting that these beneficial effects are due to amelioration of extrapancreatic complications that often contribute to mortality in acute pancreatitis. None of the antioxidants had major beneficial effects in taurocholate-induced hemorrhagic pancreatitis. Thus, formation of free radicals may be important for progression and outcome in diet-induced and, to a lesser degree, in caerulein-induced pancreatitis but not at all in taurocholate-induced pancreatitis. Different models of pancreatitis may, therefore, involve different degrees and mechanisms of free radical formation. Despite the amelioration of edema and the beneficial effects on mortality seen for some antioxidants in some of the models, antioxidants and free radical scavengers appear to have only a limited potential for treatment of acute pancreatitis.

Effects of the seleno-organic substance Ebselen in two different models of acute pancreatitis.

This study evaluated the effects of the seleno-organic substance Ebselen [2-phenyl-1,2-benzisoselenazol-3(2H)-one] in two models of acute hemorrhagic and acute edematous pancreatitis. Ebselen is known to catalyze glutathione peroxidase-like reactions and to inhibit lipid peroxidation. Hemorrhagic pancreatitis was induced by feeding a choline-deficient, ethionine-supplemented (CDE) diet to mice for 66 h. Edematous pancreatitis was induced by 7-h subcutaneous injections of 50 micrograms/kg of cerulein in mice. Ebselen was given from the beginning of the CDE diet either as a subcutaneous injection of 100 mg/kg at 6-h intervals or was mixed in with the CDE diet to yield a daily dose of 100 mg/kg of Ebselen. In further experiments, Ebselen was given at various time intervals after the beginning of the CDE diet as subcutaneous injections of 100 mg/kg at 6-h intervals. In the cerulein model, Ebselen was given 5 min prior to each cerulein injection at doses from 10-500 mg/kg. Prophylactic administration of Ebselen given orally or subcutaneously significantly improved survival from 38.5% in the control group of saline-injected CDE-fed mice to 61.9 and 65.0%, respectively. Ebselen also reduced increases in serum amylase and pancreatic weight in the diet model. Therapeutic administration of Ebselen significantly increased survival only when injections were started 20 h after the beginning of the CDE diet (64%), but not when started after 40 h (44%). Similarly, increases in serum amylase and pancreatic weight due to the CDE diet were significantly reduced by Ebselen only when injections were started after 20 h but not when started after 40 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Pancreatic exocrine secretion in acute experimental pancreatitis.

Little is known about exocrine pancreatic secretory function in patients with acute pancreatitis, in particular during the early phase of the disease. Therefore, this study evaluates basal and stimulated pancreatic secretion in vivo and in vitro in four different models of acute pancreatitis which reflect its clinical spectrum of severity: (a) edematous pancreatitis induced in the rat by seven IP injections of 50 micrograms/kg cerulein at hourly intervals; (b) edematous pancreatitis with cellular necrosis induced in the mouse by seven IP injections of 50 micrograms/kg cerulein at hourly intervals; (c) hemorrhagic pancreatitis induced in the mouse by feeding an ethionine-supplemented, choline-deficient diet for 66 hours; and (d) hemorrhagic pancreatitis induced in the rat by retrograde infusion of 0.6 mL 5% sodium taurocholate into the pancreatic duct. Secretory studies were performed in vivo and in vitro at various times after onset of pancreatitis. The results show that the exocrine pancreas gradually became resistant to cholecystokinin stimulation after the onset of acute pancreatitis in all four animal models. Cholecystokinin-stimulated secretion was almost abolished in vivo and in vitro at the time of maximal histological damage. In vivo basal secretion was also reduced. In vitro there was an increase in basal release of amylase from isolated acini that was not caused by an increase in luminal secretion but by enzyme release from damaged cells. The time course of improvement of secretory function after acute experimental pancreatitis depended on the severity of the pancreatitis. Recovery of secretory capacity took longer after severe necrotizing pancreatitis than after edematous pancreatitis. However, the ultimate resolution of secretory function was remarkable, in particular after severe hemorrhagic pancreatitis. In all four models, secretory capacity became indistinguishable from normal before the morphological alterations had completely resolved. The present experimental data suggest that pancreatic secretion, and particularly pancreatic secretory response to cholecystokinin, may also be reduced in patients early after the onset of acute pancreatitis.

Therapeutic regimens in acute experimental hemorrhagic pancreatitis. Effects of hydration, oxygenation, peritoneal lavage, and a potent protease inhibitor.

In this study we evaluated the effects of hydration, oxygenation, peritoneal lavage, and the protease inhibitor gabexate mesilate in acute hemorrhagic pancreatitis induced by feeding mice a choline-deficient, ethionine-supplemented diet. Different groups of mice were kept at various concentrations of O2 (21%, 35%, and 45% O2), or were treated by either s.c. injections or i.p. injections of electrolyte solution at various doses (0, 4, 6, or 8 ml/day). Further groups were treated either with i.p. lavage, lavage with 1.5 mg/ml of gabexate, or i.p. injections of 100 mg/kg of gabexate without lavage. The potential benefits of the various regimens were assessed by measuring survival, various biochemical and histologic features, and alterations in hematocrit, pH, and blood gases. Increasing O2 concentrations reversed hypoxemia and acidosis, but had no effect on biochemical or morphologic alterations and did not improve survival. However, hydration by s.c. fluid markedly improved survival and normalized the hematocrit without having major effects on biochemical or morphologic alterations. Intraperitoneal fluid did not improve survival. Gabexate injections without lavage had a slight effect on survival and serum amylase concentration and very little effect on histology. Lavage without gabexate had a greater effect on survival, serum amylase, and histology. Addition of gabexate to the lavage fluid increased the beneficial effect of lavage. Increases in amylase and activated trypsin in ascites were markedly reduced by lavage and even more so by lavage with addition of gabexate. We conclude that sufficient hydration appears to be an important factor in supportive care for severe acute pancreatitis, whereas oxygenation without sufficient hydration has no major benefit. Peritoneal lavage with gabexate showed the greatest benefit of the various regimens for acute severe pancreatitis and is worthy of clinical trials.

Intracellular vacuoles in experimental acute pancreatitis in rats and mice are an acidified compartment.

The appearance of vacuoles inside acinar cells characterizes an early stage of development in different models of acute pancreatitis and, possibly, also in human disease. The vacuoles have been shown to contain both digestive and lysosomal enzymes. This abnormal admixture may have important implications for the pathogenesis of pancreatitis because the lysosomal enzyme cathepsin B can activate trypsinogen and may, by this way, trigger pancreatic autodigestion. For the activation process of trypsinogen by cathepsin B, however, an acidic pH is required. This study, therefore, looked for evidence of vacuole acidification in two different models of acute pancreatitis. Edematous pancreatitis was induced in rats by hyperstimulation with cerulein and hemorrhagic pancreatitis was induced in mice by feeding a choline-deficient, ethionine-supplemented diet. Pancreatic acinar cells were isolated at different times after induction of pancreatitis and incubated with 50 microM of acridine orange to identify acidic intracellular compartments. As shown in previous work, zymogen granules are the main acidic compartment of normal acinar cells; they remained acidic throughout the course of pancreatitis in both models. Vacuoles became increasingly more frequent in both models as pancreatitis progressed. Throughout development of pancreatitis, vacuoles accumulated acridine orange indicating an acidic interior. Addition of a protonophore (10 microM monensin or 5 microM carbonyl cyanide m-chlorophenylhydrazone [CCCP] or a weak base (5 mM NH4Cl) completely and rapidly abolished acridine orange fluorescence inside both zymogen granules and vacuoles providing further evidence for an acidic interior. The acidification of vacuoles seen in two different models of pancreatitis may be an important requirement for activation of trypsinogen by cathepsin B and thus for the development of acute pancreatitis.

Beneficial effects of cholecystokinin-receptor blockade and inhibition of proteolytic enzyme activity in experimental acute hemorrhagic pancreatitis in mice. Evidence for cholecystokinin as a major factor in the development of acute pancreatitis.

The effects of the cholecystokinin (CCK)-receptor antagonist proglumide, the protease inhibitor gabexate, and the hormones secretin and cholecystokinin-octapeptide (CCK-8) were studied in a model of acute hemorrhagic pancreatitis induced by feeding mice a choline-deficient, ethionine-supplemented (CDE) diet. Injections of gabexate and proglumide from initiation of CDE diet (before induction of pancreatitis) increased survival from 37% (diet alone) to 85 and 75%, respectively, and also ameliorated histological alterations and increases in serum amylase concentration and pancreatic activated trypsin. Secretin had no major beneficial effect. When proglumide or gabexate were given after induction of pancreatitis, proglumide still increased survival to 75%, whereas gabexate no longer did. Injection of nontoxic doses of CCK-8 before proglumide or gabexate injections completely abolished all beneficial effects and also increased the severity of pancreatitis due to CDE diet alone. Blockade of CCK receptors and early inhibition of protease activity may be beneficial in severe acute pancreatitis. Cholecystokinin appears to play a contributory role in the development of pancreatitis.