Blue native electrophoresis for isolation of membrane protein complexes in enzymatically active form

A discontinuous electrophoretic system for the isolation of membrane proteins from acrylamide gels has been developed using equipment for sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Coomassie dyes were introduced to induce a charge shift on the proteins and aminocaproic acid served to improve solubilization of membrane proteins. Solubilized mitochondria or extracts of heart muscle tissue, lymphoblasts, yeast, and bacteria were applied to the gels. From cells containing mitochondria, all the multiprotein complexes of the oxidative phosphorylation system were separated within one gel. The complexes were resolved into the individual polypeptides by second-dimension Tricine-SDS-PAGE or extracted without SDS for functional studies. The recovery of all respiratory chain complexes was almost quantitative. The percentage recovery of functional activity depended on the respective protein complex studied and was zero for some complexes, but almost quantitative for others. The system is especially useful for small scale purposes, e.g., separation of radioactively labeled membrane proteins, N-terminal protein sequencing, preparation of proteins for immunization, and diagnostic studies of inborn neuromuscular diseases.

Dietary fibers: V. Binding of bile salts, phospholipids and cholesterol from mixed micelles by bile acid sequestrants and dietary fibers

Mixed micelles were prepared containing combinations of either taurocholate or taurochenodeoxycholate, monoolein, oleic acid, dioleylphosphatidylcholine (lecithin) and cholesterol. These were incubated with commercial bile-acid-sequestering resins, cholestyramine and DEAE-Sephadex, or various dietary fibers and fiber components including wheat bran, cellulose, alfalfa, lignin and 2 viscosity grades of guar gum. Binding was determined as the difference between the radioactivity of each micellar component added and that recovered in the centrifugal supernatant after incubation. In general, the extent of bile salt sequestration was characteristic and reproducible for each bile salt, and was largely unaffected by the presence of one or more additional components of the micellar mixture, including the other bile salt. Cholestyramine bound 81-92% of the bile salts and 86-99% of the phospholipid and cholesterol present in micelles. DEAE-Sephadex sequestered only 49% of the taurocholate and 84% of the taurochenodeoxycholate, but completely removed all of the phospholipid and cholesterol from micelles containing either bile salt. Among the dietary fibers, guar gum of either viscosity bound between 20-38% of each micellar component, whereas lignin, alfalfa, wheat bran and cellulose were progressively less effective in sequestration of individual components of mixed micelles. The extent of sequestration of micellar components by these resins and fibers is reasonably correlated with the effects of these same materials on lymphatic absorption of lipids and to their suggested hypocholesteremic properties.

Coexistence of simple and mixed bile salt-lecithin micelles: an NMR self-diffusion study

The aggregation behavior of bile salt and lecithin in aqueous solutions at 20 degrees C was studied from bile salt, lecithin, and aggregate self-diffusion coefficients obtained by means of a Fourier-transform NMR pulsed-gradient spin-echo technique. The results strongly support the coexistence of simple bile salt micelles and mixed bile salt-lecithin micelles under physiologic conditions.

Severity of pancreatitis-associated gut barrier dysfunction is reduced following treatment with the PAF inhibitor lexipafant

The aim of the present study was to investigate the potential effect of treatment with a platelet-activating factor (PAF) antagonist, lexipafant (BB-882), on gut endothelial and epithelial barrier dysfunction and leukocyte recruitment in rats with acute pancreatitis. Severe acute pancreatitis was induced by the intraductal administration of 5% sodium taurodeoxycholate and pancreatitis-associated gut barrier dysfunction was characterized by increased exudation of radiolabelled albumin into the interstitium and alterations in bidirectional (over both the endothelial and epithelial barrier components) permeability of the intestine at the early stage of bile salt-induced acute pancreatitis. Levels of interleukin 1beta and 6, ileal and colonic myeloperoxidase (MPO) content, clearance of radiolabelled albumin from blood to the gut lumen or gut lumen to blood, and leakage of radiolabelled albumin to the ileum or colon were measured 3 and 12h after induction of acute pancreatitis. Treatment with lexipafant 30 min and 6h after pancreatitis reduced severity of pancreatitis-associated intestinal dysfunction, associated with a diminish in systemic concentrations of IL-1 and local leukocyte recruitment. The findings imply that PAF plays a critical role in the development of pancreatitis-associated gut barrier dysfunction and that PAF antagonist in some forms may represent potential candidates for future therapeutic intervention.

Microemulsion electrokinetic chromatography of corticosteroids

The separation of neutral hydrophobic corticosteroids (cortisone, cortisone acetate, hydrocortisone, hydrocortisone acetate, prednisolone and prednisolone acetate) by microemulsion electrokinetic chromatography (MEEKC) was studied. In the preparation of microemulsion, heptane was the solvent, n-butanol the co-surfactant and, as anionic surfactants, sodium dodecyl sulfate (SDS) or taurodeoxycholic acid sodium salt (STDC) were employed. Using an acidic running buffer, (phosphate pH 2.5) a strong suppression of the electroosmotic flow (EOF) was observed; this resulted in a fast anodic migration of the analytes partitioned into the negatively charged microemulsion droplets. Under these conditions, STDC showed better separation of corticosteroids than the conventional SDS; however, the use of a single anionic surfactant did not provide the required selectivity. The addition of the neutral surfactant polyoxyethylene glycol octadecyl ether (Brij 76) significantly altered the migration of each analytes allowing a better tuning of separation; however, in order to obtain adequate resolution between couples of adjacent critical peaks, the addition of neutral cyclodextrins (CDs) was found to be essential. This apparently complex system (CD-MEEKC), was optimized by studying the effect of the most important parameters affecting separation: STDC concentration, Brij 76 concentration, nature and concentration of cyclodextrins. Following a rational step-by-step approach, the optimised conditions providing the complete separation of the analytes were found to be: 4.0% STDC, 2.5% Brij 76, 6.6% n-butanol, 1.36% heptane and 85.54% of a solution 5 mM beta-CD in 50 mM phosphate buffer (pH 2.5). The optimized system was preliminary applied to the detection of corticosteroids related substances at impurity level and it could be considered a useful orthogonal alternative to HPLC methods.

In vitro cellular interaction and absorption of dispersed cubic particles

A precursor type oily liquid formulation comprising monoolein, Pluronic F-127 and ethanol has been prepared as a carrier for lipophilic drugs. When dispersed in water, the liquid precursor formulation produces sub-micron (200-500 nm) sized lipid particles, named 'nanocubicles'. The interaction between nanocubicles and Caco-2 cell was studied, and the absorption of nanocubicles by cells was observed by various microscopic techniques. Lipid droplets were observed in cytosol after incubation with nanocubicles with time. The degree of pyrene absorption encapsulated in nanocubicles was dependent on particle size and incubation time. The amount of pyrene absorbed by Caco-2 cells was ca. 20% of total at 37 degrees C after an 8-h incubation. When nanocubicles with a bigger average particle size (ca. 600 nm) were applied, the uptake rate was reduced to 10% under identical experimental conditions. The nanocubicles were easily solubilized by bile salts to produce mixed micelles. As bile salt concentration increased, pyrene absorption into the jejunum of rat everted sac in vitro increased.

Influence of hormonal stimulation by caerulein on acute experimental pancreatitis in the rat

The influence of hormonal stimulation by caerulein administration on acute experimental pancreatitis was investigated in the rat. An experimental model of moderate acute pancreatitis was selected after injecting buffer solution containing sodium taurodeoxycholate and various concentrations of trypsin into the bile-pancreatic duct. During acute experimental pancreatitis caerulein administration increased the mortality rate, the incidence of ascites and the activity of amylase in ascites. Caerulein rendered the pancreatitis more severe also as judged from blind macroscopic evaluation. Amylase and insulin levels in serum and plasma were elevated 6 and 25 h after induction of pancreatitis irrespective of caerulein administration. In pancreatitic rats caerulein decreased the activities of digestive enzymes in pancreatic tissue. The results show that hormonal stimulation by the cholecystokinin-pancreozymin analogue caerulein during acute experimental pancreatitis is harmful.

Effect of a platelet-activating factor antagonist on pancreatitis-associated gut barrier dysfunction in rats

Platelet-activating factor (PAF) may play a critical and primary role in the pathogenesis of acute pancreatitis and pancreatitis-associated distant organ injury. The present study evaluated the effect of a PAF antagonist, lexipafant (an (S)-4-methyl-2[methyl-imidazo[4,5-c]pyridin-1-ylmethyl)-benzene sulphonyl]-amino]pentanoic acid ethyl ester, BB-882; British Biotech Ltd.), on the potential prevention of gut barrier dysfunction, by measuring gut origin sepsis, bidirectional permeability of the intestinal barrier, and pancreatic capillary endothelial barrier integrity, in acute pancreatitis induced by intraductal infusion of 5% sodium taurodeoxycholate. Pancreatic endothelial permeability significantly increased in animals with acute pancreatitis, whereas pretreatment with lexipafant had a preventive effect (p < 0.05 vs. pancreatitis with saline). Similarly, alterations noted in hematocrit and plasma levels of lipase and calcium were counteracted by the PAF antagonist. It also prevented the increase in albumin leakage from blood to the mucosal interstitium and from blood to the intestinal lumen in acute pancreatitis. Albumin passage from the gut lumen to blood in animals with pancreatitis pretreated with saline increased from 3 h and on, and lexipafant prevented alterations in mucosal epithelial permeability. Bacterial translocation was commonly seen in pancreatitis, whereas only a few positive cultures were observed in pancreatitis animals given lexipafant. Microthrombosis in intestinal villi seemed less frequent after lexipafant pretreatment. We conclude that (a) PAF may play a role in the pathogenesis of pancreatitis-associated intestinal dysfunction, (b) PAF may be involved in the development of distant organ dysfunction by triggering endothelial barrier dysfunction, and (c) PAF antagonists may provide potential agents for preventing pancreatitis-associated gut barrier dysfunction.

High-resolution proton magnetic resonance study of porcine colipase and its interactions with taurodeoxycholate

A high-resolution 270-MHz proton NMR study of procine colipase I has been performed, and the resonances in the aromatic region of the spectrum have been assigned to amino acid residues by pH titration and decoupling experiments. The apparent pKa values of the three tyrosines were calculated to be 10.2, 10.3, and 11.8 with one of the tyrosines having properties of a "buried" residue. A tentative assignment to the amino acid residues in the primary seuqence of colipase will be discussed. The effects of taurodeoxycholate (TDC) and a positively charged deoxycholate derivative on the aromatic region of the colipase NMR spectrum indicate that all tyrosines and one histidine are affected by the bile-salt binding, suggesting that the TDC molecules bind near these residues to a hydrophobic region on colipase. Measurements and calculations on the line width of the C(18) methyl group resonance suggest that the line-width increase of this resonance upon interaction of TDC with colipase to a large extent can be explained as due to the slower tumbling of the TDC molecules bound to colipase.

DSC studies of Fusarium solani pisi cutinase: consequences for stability in the presence of surfactants

The application of cutinase from Fusarium solani pisi as a fat-stain removing ingredient in laundry washing is hampered by its lack of stability in the presence of anionic surfactants. We postulate that the stability of cutinase towards anionics can be improved by mutations increasing its temperature stability. Thermal unfolding as measured with DSC, appears to be irreversible, though the thermograms are more symmetric than predicted by a simple irreversible model. In the presence of taurodeoxycholate (TDOC), the unfolding temperature is lower and the unfolding is reversible. We conclude that an early reversible unfolding intermediate exists in which a number of additional hydrophobic patches are exposed to the solvent, or preferentially are covered with TDOC. Improvement of the stability of cutinase with respect to both surfactants and thermal denaturation, should thus be directed toward the prevention of exposure of hydrophobic patches in the early intermediate.

Nitration of the tyrosine residues of porcine pancreatic colipase with tetranitromethane, and properties of the nitrated derivatives

The nitration of the long form (N-terminal valine) of porcine pancreatic colipase with tetranitromethane was investigated under a variety of conditions. Fractionation of the nitrated monomers on DE-cellulose led to well-defined derivatives containing one, two and three nitrotyrosines per mol. Automated Edman degradation of the nitrated peptides, especially that of the staphylococcal proteinase peptide (49-64) showed that Tyr-54 was nitrated very fast under all conditions. This residue was the only one to be nitrated in water. Partial nitration of Tyr-59 was induced by bile salt micelles, while both Tyr-59 and Tyr-58 reacted extensively in the presence of lysophosphatidylcholine micelles (in which tetranitromethane is concentrated 150-fold compared to water) or of a liquid tetranitromethane-water interface. The strong negative Cotton effect at 410 nm which has already been observed using unfractionated preparations of nitrated colipase (Behnke W.D. (1982) Biochim. Biophys. Acta 708, 118-123) is linked with the nitration of Tyr-59 and it is markedly reduced by taurodeoxycholate micelles, suggesting a conformational change induced by the micelles in the tyrosine region. Moreover, the pKa of the nitrotyrosine residues in nitrated colipase is the same as that of free nitrotyrosine (pKa = 6.8) and it is shifted to 7.6 in the presence of taurodeoxycholate micelles. Micelles protected colipase against polymerization during nitration. These data suggest that Tyr-58 and Tyr-59 are part of the interface recognition site of colipase. The participation of Tyr-55 in binding is not excluded. The upwards nitrotyrosine pKa shift in the colipase micelle complex may explain why nitrated colipase can reactivate lipase in a triacylglycerol-taurodeoxycholate system at pH 7.5.

Phenytoin-lipid conjugates: chemical, plasma esterase-mediated, and pancreatic lipase-mediated hydrolysis in vitro

Phenytoin-lipid conjugates obtained by covalent binding of hydroxymethylphenytoin to diacylglycerides and to 3-acyloxy-2-acyl-oxymethylpropionic acids formed dispersions with a particle size of 10-200 microns when briefly sonicated in a sodium taurodeoxycholate-containing ethanol-water mixture. In contrast to the corresponding bis-deacyl derivatives, the lipids were not significantly hydrolyzed in aqueous buffers and in plasma. Incubation with pancreatic lipase yielded primarily the bis-deacyl compounds, which are comparable to monoglycerides, and subsequently liberated phenytoin. The glyceride-derived prodrugs were better substrates for the enzyme than the 3-acyloxy-2-acyloxymethyl-propionic acid derivatives. It is concluded that the phenytoin lipid conjugates are hydrolyzed by pancreatic lipase in a similar manner as natural triglycerides.

Fatty acid transfer in taurodeoxycholate mixed micelles

Dietary triacylglycerol is acted upon by lipolytic enzymes in the stomach and the proximal small intestine, releasing fatty acids and monoacylglycerol as the ultimate products. These digestive products are solubilized by bile released from the gall bladder, resulting in the formation of two product phases-vesicles and micelles-depending upon the concentration of bile in the small intestine. Absorption of lipid is thought to occur from these two phases. We have previously examined the rate and mechanism of long-chain fatty acid transfer between unilamellar vesicles [Kleinfeld, A. M., & Storch, J. (1993) Biochemistry 32, 2053-2061]. In order to begin to assess the relative contributions of micellar vs vesicular phases in the absorption of dietary lipid, a simple model system was designed to investigate the transfer of fatty acid and monoacylglycerol between micelles. A fluorescence self-quenching assay was used to monitor the transfer of fluorescent anthroyloxy-labeled lipids from donor micelles to acceptor micelles. The mechanism of fatty acid transfer was found to be a combination of diffusional and collisional processes, with the latter dominating at high micelle concentrations. The rate of diffusional transfer of fatty acid and monoacylglycerol analogues was approximately 30-fold greater from micelles than vesicles. Intermicellar and intervesicular rates of transfer were 3-fold greater for fatty acids as compared with monoacylglycerol. The results suggest that uptake of the products of intestinal lipase hydrolysis is more efficient from micellar than vesicular phases. Nevertheless, fatty acid and monoacylglycerol transfer from unilamellar vesicles could account, in part, for the relatively efficient uptake of dietary lipid observed in conditions of intestinal bile salt insufficiency.

Assay of ganglioside GM2-N-acetyl-beta-D-galactosaminidase activity in human fibroblasts employing the natural activator protein--diagnosis of variant forms of GM2 gangliosidosis

The physiological activator protein for the degradation of ganglioside GM2 by hexosaminidase A has been employed to assess the capability of cultured human fibroblast extracts to catalyze this ganglioside. This method permits a more reliable diagnosis of the different variants of GM2 gangliosidoses than the methods hitherto used. These either rely on artificial substrates or, when natural substrates are used, on detergents. Our method avoids a number of possible sources of error introduced by the unphysiological detergents, such as alteration of the isoenzymes' substrate specificity or inactivation of the enzymes. The range of application of the new method is discussed.

Taurodeoxycholic acid and valine reverse obesity-associated augmented alloimmune responses and prolong allograft survival

Obesity initiates a chronic inflammatory network linked to perioperative complications and increased acute rejection rates in organ transplantation. Bariatric surgery is the most effective treatment of obesity recommended for morbidly obese transplant recipients. Here, we delineated the effects of obesity and bariatric surgery on alloimmunity and transplant outcomes in diet-induced obese (DIO) mice. Allograft survival was significantly shorter in DIO-mice. When performing sleeve gastrectomies (SGx) prior to transplantation, we found attenuated T cell-derived alloimmune responses resulting in prolonged allograft survival. Administering taurodeoxycholic acid (TDCA) and valine, metabolites depleted in DIO-mice and restored through SGx, prolonged graft survival in DIO-mice comparable with SGx an dampened Th1 and Th17 alloimmune responses while Treg frequencies and CD4+ T cell-derived IL-10 production were augmented. Moreover, in recipient animals treated with TDCA/valine, levels of donor-specific antibodies had been reduced. Mechanistically, TDCA/valine restrained inflammatory M1-macrophage polarization through TGR5 that compromised cAMP signaling and inhibited macrophage-derived T cell activation. Consistently, administering a TGR5 agonist to DIO-mice prolonged allograft survival. Overall, we provide novel insights into obesity-induced inflammation and its impact on alloimmunity. Furthermore, we introduce TDCA/valine as a noninvasive alternative treatment for obese transplant patients.

Initiation of acute pancreatitis by heparan sulphate in the rat

OBJECTIVE

The initiating events in the onset of pancreatitis are poorly understood. Possible candidates may be endogenous ligands, acting on receptors within ductal, acinar or stellate cells, which have previously been shown to cause a systemic inflammatory response syndrome. The aim of this study was to investigate whether acute pancreatitis could be induced by heparan sulphate (HS)infused into the pancreatic ducts in the rat.

MATERIAL AND METHODS

Retrograde biliary-pancreatic infusion of heparan sulphate of different structures, taurodeoxycholate (TDC) or phosphate buffered saline (PBS) was performed. Local pancreatic inflammation was evaluated after 6 h by means of morphological evaluation, neutrophil and macrophage infiltration and levels of plasma amylase. Systemic inflammation was evaluated by measuring plasma IL-6, MCP-1 and CINC-1 concentrations.

RESULTS

Heparan sulphate induced a local inflammatory response visualized as a rapid infiltration of neutrophils and macrophages into the pancreas. Heparan sulphate induced inflammation and oedema without causing damage to acinar cells, as measured by morphological changes and plasma amylase concentrations. Furthermore, an increase in serum concentrations of CINC-1 and IL-6 was seen. The positive control (TDC) had increased levels of all variables analysed and the negative control (heparan sulphate administered intraperitoneally) was without effects.

CONCLUSIONS

Our findings suggest a receptor-mediated innate immune response of the pancreatic cells induced by heparan sulphate. This finding may be helpful in elucidating some of the mechanisms involved during the initiation of pancreatitis, as well as in the search for a potential future therapeutic application.

Role of enteral nutrition supplemented with ebselen and EHEC in pancreatitis-associated multiple organ dysfunction in rats

OBJECTIVES

To investigate potential effects of ebselen and ethylhydroxyethyl cellulose (EHEC) on the acute phase responses and the severity of multiple organ dysfunction associated with acute pancreatitis.

METHODS

Acute pancreatitis was induced by intraductal infusion of 5% sodium taurodeoxycholate. The increase of total protein content in the BALF was used as an indication for acute lung injury, plasma amylase for pancreatic damage, plasma bilirubin for acute liver dysfunction, and plasma creatinine for acute kidney dysfunction. Levels of interleukin (IL)-6, macrophage inflammatory protein (MIP)-2 in the BALF were determined by ELISA.

RESULTS

There was a dose-related tendency for ebselen or EHEC alone to prevent organ dysfunction and reduce elevated plasma levels of IL-6 and ICAM-1 expression on circulating leukocytes 12 h after AP induction. The combination of ebselen and EHEC significantly prevented pancreatitis-induced multiple organ injury, IL-6 production and ICAM-1 expression in rats and exhibited better effects than either monocompound alone.

CONCLUSION

The combination of ebselen and EHEC may be a new potential for treatment of acute severe pancreatitis.

Potential effects of PKC or protease inhibitors on acute pancreatitis-induced tissue injury in rats

BACKGROUND

Acute pancreatitis (AP) is still one of the severe diseases, that cause the development of multiple organ dysfunction with a high mortality. Effective therapies for AP are still limited, mainly due to unclear mechanisms by which AP initiates both pancreatic and extrapancreatic organ injury.

METHODS

Protease inhibitors (aprotinin, pefabloc, trypsin inhibitor) and PKC inhibitors (polymyxin B, staurosporine) were administrated 30 min before induction of AP in rats. To investigate the pancreatic, systemic and lung inflammatory response and injury, plasma IL-6 and IL-10, pancreatic and pulmonary myeloperoxidase (MPO) levels, pancreatic protease activity and phospholipase A(2) (PLA(2)) activity in ascites were measured 3 and 6 h after AP induction.

RESULTS

Pretreatment with protease inhibitors significantly prevented from AP-increased plasma levels of IL-10, pancreatic and pulmonary levels of MPO, pancreatic protease activity and the catalytic activity of PLA(2) in ascites. PKC inhibitors significantly reduced pancreatic and pulmonary levels of MPO and pancreatic protease activity.

CONCLUSION

Inhibition of proteases in AP may be helpful in ameliorating the inflammatory reaction in both pancreatic and extrapancreatic tissues, where neutrophil involvement may be regulated by PKC and proteases.

Analysis of ecdysteroids by micellar electrokinetic chromatography with on-line preconcentration

In order to enhance the UV detection sensitivity, an application study of an on-line preconcentration technique for micellar electrokinetic chromatographic (MEKC) was carried out. The simultaneous determination of four test ecdysteroids, 20-hydroxyecdysone, ajugasterone C, polypodine B and ponasterone A has been investigated by using the normal stacking mode in MEKC with UV detection. The effects of anionic surfactant composition and concentration, the applied voltage, the pH buffer, the kind and the amount of organic solvent and the injection time on the analyte resolution were evaluated. The optimised conditions for the separation involved the use of a 50 mM borate as the running buffer containing 50 mM of a mixture of sodium dodecyl sulphate (SDS) and sodium cholate (SC) in the ratio of 1:1 together with a concentration of 10% (v/v) of 2-PrOH at pH 9.0. Hydrodynamic injection of 12 s at 50 mbar and separation voltage of 20 kV at temperature of 20 degrees C were employed. These conditions allowed a repeatability separation within 21 min. Concentration detection limit for the neutral analytes studied improve about an order of magnitude. The method was also applied to the determination of ecdysteroids in a real sample.

Protein kinase C modulates the pulmonary inflammatory response in acute pancreatitis

The present study aims at evaluating the role of protein kinase C (PKC) in the development of acute lung injury, production of inflammatory mediators and expression of adhesion molecules on leukocytes after induction of acute pancreatitis (AP). AP was induced by the intraductal infusion of 5% sodium taurodeoxycholate in the rat. The animals had the PKC inhibitor polymyxin B administered intraperitoneally 30min prior to induction of AP. Levels of protein content, protease activity, cytokines and chemokines in bronchoalveolar lavage fluid (BALF) were assessed 1 and 6h after AP induction. Adhesion molecule expression on leukocytes were measured by flowcytometry. Pretreatment with polymyxin B prevented against acute pancreatitis-induced lung injury and the otherwise occurring increases in TNF-alpha, IL-1beta, MCP-1 and IL-10, as well as against the decreases in IL-2, IFNgamma and TIMP-1, decreased protease activity and down-regulation of CD31, CD54 and CD62L on recruited neutrophils and macrophages in BALF. The results indicate that the leukocyte response in acute pancreatitis vary depending on leukocyte subpopulation. It seems that activation of the PKC signalling pathway may play an important role in pancreatitis-associated lung injury.

Effects of high dose octreotide on retrograde bile salt-induced pancreatitis in rats

The effects of somatostatin and octreotide (a long acting somatostatin analogue) in acute pancreatitis are inconclusive. This study examined the prophylactic and therapeutic effects of different doses of octreotide on retrograde sodium taurodeoxycholate-induced acute necrotizing pancreatitis in rats. The rats were divided into 4 groups receiving subcutaneous injection of saline, octreotide 10 microg/kg, 20 microg/kg at 0, 8 and 16 h and octreotide 20 microg/kg at 5, 13 and 21 h, separately. The serum levels of amylase and lipase, pancreatic histopathology, mortality and hemodynamics were examined. Octreotide significantly reduced serum levels of amylase and lipase at 12 h and the degree of pancreatic edema, necrosis and hemorrhage at 18-24 h as compared to the control group. Prophylactic octreotide 10 microg/kg significantly decreased the 24-h mortality from 100% to 44.4% (p < 0.05). The 24-h mortality further reduced to 12.5% and 10% with prophylactic and therapeutic octreotide 20 microg/kg, respectively. The decrease of mean arterial pressure at 12 h was significantly lower in octreotide groups than in the control group. We conclude that octreotide improves pancreatic histopathology and survival in acute necrotizing pancreatitis in rats.

The resorption of FITC-dextran 10,000 from the peritoneum in different modifications of bile-induced acute pancreatitis and in bacterial peritonitis

The resorption from the peritoneum of fluorescein-isothiocyanate-conjugated (FITC) dextran with a mol wt of 10,000 was studied after 6, 15, and 24 h in rats with (1) only laparotomy (LC), (2) bacterial peritonitis (BP), (3) bile-induced acute pancreatitis (AP), (4) acute pancreatitis induced with contaminated bile (AIP), and (5) cerulein administration during acute pancreatitis (CAP). Animals in the AIP and CAP groups had a significantly higher mortality rate at 24 h and higher hematocrit at 6 h, indicating severe disease in these animals. At 6 and 15 h, all groups displayed similar peritoneal resorption. After 24 h, all groups with active inflammation showed significantly higher resorption than laparotomy controls. We conclude that peritoneal resorption as defined is independent of the severity and mode of induction of acute experimental pancreatitis and that it is the same as in bacterial peritonitis.