α-Lipoic acid protects against cholecystokinin-induced acute pancreatitis in rats

AIM:α-Lipoic acid (ALA) has been used as an antioxidant. The aim of this study was to investigate the effect of α-lipoic acid on cholecystokinin (CCK)-octapeptide induced acute pancreatitis in rats. METHODS: ALA at 1 mg/kg was intra-peritoneally injected, followed by 75 μg/kg CCK-octapeptide injected thrice subcutaneously after 1, 3, and 5 h. This whole procedure was repeated for 5 d. We checked the pancreatic weight/body weight ratio, the secretion of pro-inflammatory cytokines and the levels of lipase, amylase of serum. Repeated CCK octapeptide treatment resulted in typical laboratory and morphological changes of experimentally induced pancreatitis. RESULTS: ALA significantly decreased the pancreatic weight/body weight ratio and serum amylase and lipase in CCK octapeptide-induced acute pancreatitis. However, the secretion of IL-1β, IL-6, and TNF-α were comparable in CCK octapeptide-induced acute pancreatitis. CONCLUSION: ALA may have a protective effect against CCK octapeptide-induced acute pancreatitis.     

Tetrandrine inhibits activation of rat hepatic stellate cells in vitro via transforming growth factor-β signaling

AIM: To investigate the effect of various concentrations of tetrandrine on activation of quiescent rat hepatic stellate cells (HSCs) and transforming growth factor-β(TGF-β) signaling in vitro. METHODS: HSCs were isolated from rats by in situ perfusion of liver and 18% Nycodenz gradient centrifugation, and primarily cultured on uncoated plastic plates for 24 h with DMEM containing 20% fetal bovine serum (FBS/ DMEM) before the culture medium was substituted with 2% FBS/DMEM for another 24 h. Then, the HSCs were cultured in 2% FBS/DMEM with tetrandrine (0.25, 0.5, 1, 2 mg/L, respectively). Cell morphological features were observed under an inverted microscope, smooth muscle-α-actin (α-SMA) was detected by immunocytochemistry and image analysis system, laminin (LN) and type Ⅲ procollagen (PCⅢ) in supernatants were determined by radioimmunoassay. TGF-β1 mRNA, Smad 7 mRNA and Smad 7 protein were analyzed with RT-PCR and Western blotting, respectively. RESULTS: Tetrandrine at the concentrations of 0.25-2 mg/L prevented morphological transformation of HSC from the quiescent state to the activated one, while α-SMA, LN and PCⅢ expressions were inhibited. As estimated by gray values, the expression of α-SMA in tetrandrine groups (0.25, 0.5, 1, 2 mg/L) was reduced from 21.3% to 42.2% (control: 0.67, tetrandrine groups: 0.82, 0.85, 0.96, or 0.96, respectively, which were statistically different from the control, P<0.01), and the difference was more significant in tetrandrine at 1 and 2 mg/L. The content of LN in supernatants was significantly decreased in tetrandrine groups to 58.5%, 69.1%, 65.8% or 60.0% that of the control respectively, and that of PCⅢ to 84.6%, 81.5%, 75.7% or 80.7% respectively (P<0.05 vs control), with no significant difference among tetrandrine groups. RT-PCR showed that TGF-β1 mRNA expression was reduced by tetrandrine treatments from 56.56% to 87.90% in comparison with the control, while Smad 7 mRNA was increased 1.4-4.8 times. The TGF-β1 mRNA and Smad 7 mRNA expression was in a significant negative correlation (r= -0.755, P<0.01), and both were significantly correlated with α-SMA protein expression (r= -0.938, P<0.01; r = 0.938,P<0.01, respectively). The up-regulation of Smad 7 protein by tetrandrine (1 mg/L) was confirmed by Western blotting as well. CONCLUSION: Tetrandrine has a direct inhibiting effect on the activation of rat HSCs in culture. It up-regulates the expression of Smad 7 which in turn blocks TGF-β1 expression and signaling.     

Therapeutic proteasome inhibition in experimental acute pancreatitis

AIM: To establish the therapeutic potential of proteasome inhibition, we examined the therapeutic effects of MG132 (Z-Leu-Leu-Leu-aldehyde) in an experimental model of acute pancreatitis.METHODS: Pancreatitis was induced in rats by two hourly intraperitoneal (ip) injections of cholecystokinin octapeptide (CCK; 2 x 100 μg/kg) and the proteasome inhibitor MG132 (10 mg/kg ip) was administered 30 min after the second CCK injection. Animals were sacrificed 4 h after the first injection of CCK.RESULTS: Administering the proteasome inhibitor MG132 (at a dose of 10 mg/kg, ip) 90 min after the onset of pancreatic inflammation induced the expression of cell-protective 72 kDa heat shock protein (HSP72) and decreased DNA-binding of nuclear factor-kB (NF-kB). Furthermore MG132 treatment resulted in milder inflammatory response and cellular damage, as revealed by improved laboratory and histological parameters of pancreatitis and associated oxidative stress.CONCLUSION: Our findings suggest that proteasome inhibition might be beneficial not only for the prevention, but also for the therapy of acute pancreatitis.     

Pioglitazone, a specific ligand of peroxisome proliferator-activated receptor-gamma, protects pancreas against acute cerulein-induced pancreatitis

ABM: To determine the effect of pioglitazone, a specific peroxisome proliferator-activated receptor-γ(PPARγ) ligand, on the development of acute pancreatitis (AP) and on the expression of heat shock protein 70 (HSP70) in the pancreas. METHODS: AP was induced in rats by subcutaneous infusion of cerulein for 5 h. Pancreatic blood flow was measured by laser Doppler flowmetry. Plasma lipase activity, interleukin-1β (IL-1β) and IL-10 were determined, Pancreatic weight and histology were evaluated and pancreatic DNA synthesis and blood flow as well as pancreatic mRNA for IL-1β and HSP70 were assessed in rats treated with pioglitazone alone or in combination with cerulein. RESULTS: Pioglitazone administered (10-100 mg/kg i.g.) 30 min before cerulein, attenuated dose-dependently the pancreatic tissue damage in cerulein-induced pancreatitis (CIP) as demonstrated by the improvement of pancreatic histology, reduction in plasma lipase activity, plasma concentration of pro-inflammatory IL-1β and its gene expression in the pancreas and attenuation of the pancreatitis-evoked fall in pancreatic blood flow. CIP increased pancreatic HSP70 mRNA and protein expression in the pancreas and this effect was enhanced by pioglitazone treatment. CONCLUSION: Pioglitazone attenuates CIP and the beneficial effect of this pioglitazone is multifactorial probably due to its anti-inflammatory activities, to the suppression of IL-1β and to the over-expression of HSP70. PPARγ ligands could represent a new therapeutic option in the treatment of AP.     

Taraxacum officinale protects against cholecystokinin-induced acute pancreatitis in rats

AIM: Taraxacum officinale (TO) has been frequently used as a remedy for inflammatory diseases. The aim of this study was to investigate the effect of TO on cholecystokinin (CCK)-octapeptide-induced acute pancreatitis in rats.METHODS: TO at 10 mg/kg was orally administered, followed by 75 μg/kg CCK octapeptide injected subcutaneously three times after 1, 3 and 5 h. This whole procedure was repeated for 5 d. We determined the pancreatic weight/body weight ratio, the levels of pancreatic HSP60 and HSP72, and the secretion of pro-inflammatory cytokines. Repeated CCK octapeptide treatment resulted in typical laboratory and morphological changes of experimentally-induced pancreatitis.RESULTS: TO significantly decreased the pancreatic weight/body weight ratio in CCK octapeptide-induced acute pancreatitis. TO also increased the pancreatic levels of HSP60 and HSP72. Additionally, the secretion of IL-6 and TNF-α decreased in the animals treated with TO.CONCLUSION: TO may have a protective effect against CCK octapeptide-induced acute pancreatitis.     

Taraxacum offlcinale protects against cholecystokinin-induced acute pancreatitis in rats

AIM: Taraxacum officinale (TO) has been frequently used as a remedy for inflammatory diseases. The aim of this study was to investigate the effect of TO on cholecystokinin (CCK)-octapeptide-induced acute pancreatitis in rats. METHODS: TO at 10 mg/kg was orally administered, followed by 75 μg/kg CCK octapeptide injected subcutaneously three times after 1, 3 and 5 h. This whole procedure was repeated for 5 d. We determined the pancreatic weight/body weight ratio, the levels of pancreatic HSP60 and HSP72, and the secretion of pro-inflammatory cytokines. Repeated CCK octapeptide treatment resulted in typical laboratory and morphological changes of experimentally-induced pancreatitis. RESULTS: TO significantly decreased the pancreatic weight/body weight ratio in CCK octapeptide-induced acute pancreatitis. TO also increased the pancreatic levels of HSP60 and HSP72. Additionally, the secretion of IL-6 and TNF-α decreased in the animals treated with TO. CONCLUSION: TO may have a protective effect against CCK octapeptide-induced acute pancreatitis.     

Tetrandrine inhibits activation of rat hepatic stellate cells in vitro via transforming growth factor-β signaling

AIM: To investigate the effect of various concentrations of tetrandrine on activation of quiescent rat hepatic stellate cells (HSCs) and transforming growth factor-β (TGF-β) signaling in vitro. METHODS: HSCs were isolated from rats by in situ perfusion of liver and 18% Nycodenz gradient centrifugugation, and primarily cultured on uncoated plastic plates for 24 h with DMEM containing 20% fetal bovine serum (FBS/DMEM) before the culture medium was substituted with 2% FBS/DMEM for another 24 h. Then, the HSCs were cultured in 2% FBS/DMEM with tetrandrine (0.25, 0.5, 1,2 mg/L, respectively). Cell morphological features were observed under an inverted microscope, smooth muscle-α-actin (α-SMA) was detected by immunocytochemistry and image analysis system, laminin (LN) and type Ⅲ procollagen (PCⅢ) in supernatants were determined by radioimmunoassay. TGF-β1 mRNA, Smad 7 mRNA and Smad 7 protein were analyzed with RT-PCR and Western blotting, respectively. RESULTS: Tetrandrine at the concentrations of 0.25-2 mg/L prevented morphological transformation of HSC from the quiescent state to the activated one, while α-SMA, LN and PCⅢ expressions were inhibited. As estimated by gray values, the expression of α-SMA in tetrandrine groups (0.25, 0.5, 1, 2 mg/L) was reduced from 21.3% to 42.2% (control: 0.67, tetrandrine groups: 0.82, 0.85, 0.96, or 0.96, respectively, which were statistically different from the control, P&lt;0.01), and the difference was more significant in tetrandrine at 1 and 2 mg/L. The content of LN in supernatants was significantly decreased in tetrandrine groups to 58.5%, 69.1%, 65.8% or 60.0% that of the control respectively, and that of PCII] to 84.6%, 81.5%, 75.7% or 80.7% respectively (P&lt;0.05 vs control), with no significant difference among tetrandrine groups. RTPCR showed that TGF-β1 mRNA expression was reduced by tetrandrine treatments from 56.56% to 87.90% in comparison with the control, while Smad 7 mRNA was increased 1.4-4.8 times. The TGF-β1 mRNA and Smad 7 mRNA expression was in a significant negative correlation (r = -0.755, P&lt;0.01), and both were significantly correlated with α-SMA protein expression (r = -0.938, P&lt;0.01; r = 0.938, P&lt;0.01, respectively). The up-regulation of Smad 7 protein by tetrandrine (1 mg/L) was confirmed by Western blotting as well. CONCLUSION: Tetrandrine has a direct inhibiting effect on the activation of rat HSCs in culture. It up-regulates the expression of Smad 7 which in turn blocks TGF-β1 expression and signaling.     

Inhibition of small-intestinal sugar absorption mediated by sodium orthovanadate Na3VO4 in rats and its mechanisms

AIM: To investigate the inhibitory effects of sodium orthovanadate on small-intestinal glucose and maltose absorption in rats and its mechanism.METHODS: Normal Wistar rats were lavaged with sodium orthovanadate (16 mg/kg, 4 mg/kg and 1 mg/kg) for 6 d.Blood glucose values were measured after fasting and 0.5, 1, 1.5 and 2 h after glucose and maltose feeding with oxidation-enzyme method, α-glucosidase was abstracted from the upper small intestine, and its activity was examined.mRNA expression of α-glucosidase and glucose-transporter 2 (GLUT2) in epithelial cells of the small intestine was observed by in situ hybridization.RESULTS: Sodium orthovanadate could delay the increase of plasma glucose concentration after glucose and maltose loading, area under curve (AUC) in these groups was lower than that in control group. Sodium orthovanadate at dosages of 10 μmol/L, 100 μmol/L and 1000 μmol/L could suppress the activity of α-glucosidase in the small intestine of normal rats, with an inhibition rate of 68.18%, 87.22% and 91.91%,respectively. Sodium orthovanadate reduced mRNA expression of α-glucosidase and GLUT2 in epithelial cells of small intestine.CONCLUSION: Sodium orthovanadate can reduce and delay the absorption of glucose and maltose. The mechanism may be that it can inhibit the activity and mRNA expression of α-glucosidase, as well as mRNA expression of GLUT2 in small intestine.     

Pancreatitis in pregnancy：etiology,diagnosis, treatment,and outcomes

BACKGROUND: Acute pancreatitis in pregnancy is a rare and dangerous disease. This study aimed to examine the etiology, treatment, and outcomes of pancreatitis in pregnancy.
METHOD: A total of 25 pregnant patients diagnosed with pancreatitis during the period of 1994 and 2014 was analyzed retrospectively.
RESULTS: The pregnant patients were diagnosed with pancre-atitis during a period of 21 years. Most (60%) of the patients were diagnosed with pancreatitis in the third trimester. The mean age of the patients at presentation was 25.7 years, with a mean gestational age of 24.4 weeks. Abdominal pain occurred in most patients and vomiting in one patient was associated hyperemesis gravidarum. The common cause of the disease was gallstone-related (56%), followed by alcohol-related (16%), post-ERCP (4%), hereditary (4%) and undetermined condi-tions (20%). The level of triglycerides was minimally high in three patients. ERCP and wire-guided sphincterotomy were performed in 6 (43%) of 14 patients with gallstone-related pancreatitis and elevated liver enzymes with no complications. Most (84%) of the patients underwent a full-term, vaginal delivery. There was no difference in either maternal or fetal outcomes after ERCP.
CONCLUSIONS: Acute pancreatitis is rare in pregnancy, oc-curring most commonly in the third trimester, and gallstones are the most common cause. When laparoscopic cholecystec-tomy is not feasible and a common bile duct stone is highly suspected on imaging, endoscopic sphincterotomy or stenting may help to prevent recurrence and postpone cholecystectomy until after delivery.     

Down-regulation of transforming growth factor β1/activin receptor-like kinase 1 pathway gene expression by herbal compound 861 is related to deactivation of LX-2 cells

AIM: To investigate the effect of herbal compound 861(Cpd861) on the transforming growth factor-131 (TGFβ1)/activin receptor-like kinase 1 (ALK1, type I receptor)signaling-pathway-related gene expression in the LX-2 cell line, and the inhibitory mechanism of Cpd861 on the activation of LX-2 cells.METHODS: LX-2 cells were treated with TGFβ1(5 ng/mL) Cpd861 (0.1 mg/mL), TGFβ1 (5 ng/mL) plus Cpd861 (5 ng/mL) for 24 h to investigate the effect of Cpd861 on the TGFβ1/ALK1 pathway. Real-time PCR was performed to examine the expression of α-SMA (α-smooth muscle actin), ALK1, Id1 (inhibitor of differentiation 1). Western blotting was carried out to measure the levels of α-SMA and phosphorylated Smadl,and immunocytochemical analysis for the expression of α-SMA.RESULTS: In LX-2 cells, TGFβ1/ALK1-pathway-related gene expression could be stimulated by TGFβ1, which led to excessive activation of the cells. Cpd861 decreased the activation of LX-2 cells by reducing the expression of α-SMA mRNA and protein expression. This effect was related to inhibition of the above TGFβ1/ALK1-pathwayrelated expression of genes such as Id1 and ALK1, and phosphorylation of Smad1 in LX-2 cells, even with TGFβ1 co-treatment for 24 h.CONCLUSION: Cpd861 can restrain the activation of LX-2 cells by inhibiting the TGFβ1/ALK1/Smad1 pathway.     

Clinical value of rapid urine trypsinogen-2 test strip, urinary trypsinogen activation peptide, and serum and urinary activation peptide of carboxypeptidase B in acute pancreatitis

AIM: To assess the usefulness of urinary trypsinogen-2 test strip, urinary trypsinogen activation peptide (TAP), and serum and urine concentrations of the activation peptide of carboxypeptidase B (CAPAP) in the diagnosis of acute pancreatitis. METHODS: Patients with acute abdominal pain and hospitalized within 24 h after the onset of symptoms were prospectively studied. Urinary trypsinogen-2 was considered positive when a clear blue line was observed (detection limit 50 μg/L). Urinary TAP was measured using a quantitative solid-phase ELISA, and serum and urinary CAPAP by a radioimmunoassay method. RESULTS: Acute abdominal pain was due to acute pancreatitis in 50 patients and turned out to be extrapancreatic in origin in 22 patients. Patients with acute pancreatitis showed significantly higher median levels of serum and urinary CAPAP levels, as well as amylase and lipase than extrapancreatic controls. Median TAP levels were similar in both groups. The urinary trypsinogen-2 test strip was positive in 68% of patients with acute pancreatitis and 13.6% in extrapancreatic controls (P<0.01). Urinary CAPAP was the most reliable test for the diagnosis of acute pancreatitis (sensitivity 66.7%, specificity 95.5%, positive and negative predictive values 96.6% and 56.7%, respectively), with a 14.6 positive likelihood ratio for a cut-off value of 2.32 nmol/L. CONCLUSION: In patients with acute abdominal pain, hospitalized within 24 h of symptom onset, CAPAP in serum and urine was a reliable diagnostic marker of acute pancreatitis. Urinary trypsinogen-2 test strip showed a clinical value similar to amylase and lipase. Urinary TAP was not a useful screening test for the diagnosis of acute pancreatitis.     

Pituitary adenylate cyclase activating-peptide and its receptor antagonists in development of acute pancreatitis in rats

AIM: Pituitary adenylate cyclase activating-peptide (PACAP) is a late member of the secretin/glucagon/vasoactive intestinal peptide (VIP) family of brain-gut peptides. It is unknown whether PACAP takes part in the development of acute pancreatitis and whether PACAP or its antagonists can be used to suppress the progression of acute pancreatitis. We investigated the actions of PACAP and its receptor antagonists in acute pancreatitis on rats. METHODS: Acute pancreatitis was induced in rats with caerulein or 3.5% sodium taurocholate. The rats were continuously infused with 5-30 μg/kg PACAP via jugular vein within the first 90 min, while 10-100 μg/kg PACAP6-27 and (4-CI-D-Phe6, Leu17) VIP (PACAP receptor antagonists) were intravenously infused for 1 h. Biochemical and histopathological assessments were made at 4 h after infusion. Pancreatic and duodenal PACAP concentrations were determined by enzyme-linked immunosorbent assay (ELISA). Chinese ink-perfused pancreas was fixed, sectioned and cleared for counting the functional capillary density. RESULTS: PACAP augmented caerulein-induced pancreatitis and failed to ameliorate sodium taurocholate-induced pancreatitis. ELISA revealed that relative concentrations of PACAP in pancreas and duodenum were significantly increased in both sodium taurocholate- and caerulein-induced pancreatitis compared with those in normal controls. Unexpectedly, PACAP6-27 and (4-CI-D-Phe6, Leu17) VIP could induce mild acute pancreatitis and aggravate caerulein-induced pancreatitis with characteristic manifestations of acute hemorrhagic/necrotizing pancreatitis. Functional capillary density of pancreas was interpreted in the context of pancreatic edema, and calibrated functional capillary density (calibrated FCD), which combined measurement of functional capillary density with dry weight/wet weight ratio, was introduced. Hyperemia or congestion, rather than ischemia, characterized pancreatic microcirculatory changes in acute pancreatitis. CONCLUSION: PACAP may take part in the pathogenesis of acute pancreatitis in rats. The two PACAP receptor antagonsits might act as partial agonists. Calibrated functional capillary density can reflect pancreatic microcirculatory changes in acute pancreatitis.     

Inhibition of small-intestinal sugar absorption mediated by sodium orthovanadate Na_3VO_4 in rats and its mechanisms

AIM:To investigate the inhibitory effects of sodiumorthovanadate on small-intestinal glucose and maltoseabsorption in rats and its mechanism.METHODS:Normal Wistar rats were tavaged with sodiumorthovanadate (16 mg/kg,4 mg/kg and 1 mg/kg) for 6 d.Blood glucose values were measured after fasting and0.5,1,1.5 and 2 h after glucose and maltose feeding withoxidation-enzyme method.α-glucosidase was abstractedfrom the upper small intestine,and its activity was examined.mRNA expression of α-glucosidase and glucose-transporter2 (GLUT2) in epithelial cells of the small intestine wasobserved by in situ hybridization.RESULTS:Sodium orthovanadate could delay the increaseof plasma glucose concentration after glucose and maltoseloading,area under curve (AUC) in these groups was lowerthan that in control group.Sodium orthovanadate at dosagesof 10 μmol/L,100 μmol/L and 1000 μmol/L could suppressthe activity of α-glucosidase in the small intestine of normalrats,with an inhibition rate of 68.18%,87.22% and 91.91%,respectively.Sodium orthovanadate reduced mRNA expressionof α-glucosidase and GLUT2 in epithelial cells of smallintestine.CONCLUSION:Sodium orthovanadate can reduce and delaythe absorption of glucose and maltose.The mechanismmay be that it can inhibit the activity and mRNA expressionof α-glucosidase,as well as mRNA expression of GLUT2 insmall intestine.     

Effect of carvedilol on attenuating the acute myocardial infarction-induced myocardial fibrosis in rats

Carvedilol,nonselective β-adrenoreceptor antagonist,was showed protective effects against acute myocardial infarction(AMI)-induced myocardial injury,however,the mechanisms underlying the antifibrosis effect of carvedilol has not been well known.The aim of the present study was to investigate the potential mechanism for the anti-fibrosis effect of carvedilol against AMI-induced myocardial fibrosis in rats.Methods Male SD rats were randomized into the sham group,LAD surgery-AMI model group,AMI plus low dose of carvedilol treatment group(1 mg /kg per day,CAR-L),AMI plus medium dose of carvedilol treatment group(5 mg /kg per day,CAR-M) and AMI plus high dose of carvedilol treatment group(10 mg /kg per day,CAR-H).The passage 3 neonatal SD rat cardiac fibroblasts were used for hypoxia /normoxia(2 h /4 h) treatment in the presence of carvedilol(0,1,2 and 4 μM).Results Cardiac remodeling and impaired heart function were observed after 14-week LAD surgery treatment,however,and the cardiac remodeling and decreased ejection fraction(EF%) and fractional shortening(FS%) were efficiently rescued in the CAR-M and CAR-H groups.The up-regulated expressions of Col1a1,Col3a1 and α-SMA at mRNA and protein levels were significantly reduced in the CAR-M and CAR-H groups.The in vitro study showed that Col1a1,Col3a1 and αSMA expressions at both mRNA and protein levels were down-regulated by carvedilol in rat cardiac fibroblasts in a dose-dependent manner.Smad3 inhibitors,SIS-3 and naringenin,could efficiently decrease Col1a1,Col3a1 and α-SMA expressions in rat cardiac fibroblasts.Smad3 was shown significantly inactivated in carvedilol-treated rat cardiac fibroblasts.Conclusion Carvedilol negatively regulates Smad3 signal pathway and inhibits extracellular matrix related Col1a1,Col3a1 and α-SMA expressions,contributing to the anti-fibrosis effect of carvedilol against AMI-induced myocardial fibrosis in rats.     

Ischemic preconditioning inhibits development of edematous cerulein-induced pancreatitis： Involvement of cyclooxygenases and heat shock protein 70

AIM: To determine whether ischemic preconditioning (IP) affects the development of edematous cerulein-induced pancreatitis and to assess the role of cyclooxygenase-1 (COX-1), COX-2, and heat shock protein 70 (HSP 70) in this process, METHODS: In male Wistar rats, IP was performed by clamping of celiac artery (twice for 5 min at 5-min intervals). Thirty minutes after IP or sham operation, acute pancreatitis was induced by cerulein. Activity of COX-1 or COX-2 was inhibited by resveratrol or rofecoxib, respectively (10 mg/kg). RESULTS: IP significantly reduced pancreatic damage in cerulein-induced pancreatitis as demonstrated by the improvement of pancreas histology, reduction in serum lipase and poly-C ribonuclease activity, and serum concentration of pro-inflammatory interleukin (IL)-lp. Also, IP attenuated the pancreatitis-evoked fall in pancreatic blood flow and pancreatic DNA synthesis. Serum level of anti-inflammatory IL-10 was not affected by IP. Cerulein-induced pancreatitis and IP increased the content of HSP 70 in the pancreas. Maximal increase in HSP 70 was observed when IP was combined with cerulein-induced pancreatitis. Inhibition of COXs, especially COX-2, reduced the protective effect of IP in edematous pancreatitis. CONCLUSION: Our results indicate that IP reduces pancreatic damage in cerulein-induced pancreatitis and this effect, at least in part, depends on the activity of COXs and pancreatic production of HSP 70.     

Lexipafant fails to improve survival in severe necrotizing pancreatitis in rats

Summary Conclusions. Lexipafant administration fails to improve survival or lessen the disease severity in two experimental models of severe acute pancreatitis. Background. The potent platelet activating factor antagonist Lexipafant has been shown to attenuate the biochemical and histologic changes associated with some animal models of acute pancreatitis, suggesting an important role for this cytokine in its pathogenesis. However, a survival advantage following Lexipafant administration has not been demonstrated. This study evaluates the effect of this platelet activating antagonist on survival in rat models of necrotizing and fulminant hemorrhagic pancreatitis. Methods. Sprague-Dawley rats underwent induction of either acute necrotizing (n=40) or hemorrhagic pancreatitis (n=36) with a time- and pressure-controlled bile duct infusion of 10 mM glycodeoxycholic acid (GDOC) or enterokinase 15 U/mL, in combination with supramaximal cerulein stimulation (5 μg/kg/h). Immediately after pancreatitis induction, rats were randomly divided into three groups and received Lexipafant (1 mg or 10 mg) or saline as a continuous intravenous infusion over 9 h. Twenty-four-hour survival rates were determined and severity of pancreatitis was assessed by pancreatic histology scores. Results. The survival rates for GDOC treated rats were 55% (saline), 50% (1 mg Lexipafant) and 50% (10 mg Lexipafant). As expected, all rats induced with enterokinase and treated with saline died with hemorrhagic pancreatitis within 24 h. The same was true of those treated with high- and low-dose Lexipafant, and there was no difference in survival time. Histology scores did not differ between Lexipafant-treated and control rats in either GDOC or enterokinase rats.     

Randomized controlled trial of pancreatic stenting to prevent pancreatitis after endoscopic retrograde cholangiopancreatography

AIM:To determine the effectiveness of pancreatic duct(PD) stent placement for the prevention of pancreatitis after endoscopic retrograde cholangiopancreatography(ERCP) in high risk patients.METHODS:Authors conducted a single-blind,randomized controlled trial to evaluate the effectiveness of a pancreatic spontaneous dislodgement stent against post-ERCP pancreatitis,including rates of spontaneous dislodgement and complications.Authors defined high risk patients as having any of the following:sphincter of Oddi dysfunction,difficult cannulation,prior history of post-ERCP pancreatitis,pre-cut sphincterotomy,pancreatic ductal biopsy,pancreatic sphincterotomy,intraductal ultrasonography,or a procedure time of more than 30 min.Patients were randomized to a stent group(n = 60) or to a non-stent group(n = 60).An abdominal radiograph was obtained daily to assessspontaneous stent dislodgement.Post-ERCP pancreatitis was diagnosed according to consensus criteria.RESULTS:The mean age(± standard deviation) was 67.4 ± 13.8 years and the male:female ratio was 68:52.In the stent group,the mean age was 66 ± 13 years and the male:female ratio was 33:27,and in the non-stent group,the mean age was 68 ± 14 years and the male:female ratio was 35:25.There were no significant differences between groups with respect to age,gender,final diagnosis,or type of endoscopic intervention.The frequency of post-ERCP pancreatitis in PD stent and non-stent groups was 1.7%(1/60) and 13.3%(8/60),respectively.The severity of pancreatitis was mild in all cases.The frequency of post-ERCP pancreatitis in the stent group was significantly lower than in the non-stent group(P = 0.032,Fisher's exact test).The rate of hyperamylasemia were 30%(18/60) and 38.3%(23 of 60) in the stent and non-stent groups,respectively(P = 0.05,χ2 test).The placement of a PD stent was successful in all 60 patients.The rate of spontaneous dislodgement by the third day was 96.7%(58/60),and the median(range) time to dislodgement was 2.1(2-3) d.The rates of stent migration,hemorrhage,perforation,infection(cholangitis or cholecystitis) or other complicationss were 0%(0/60),0%(0/60),0%(0/60),0%(0/60),0%(0/60),respectively,in the stent group.Univariate analysis revealed no significant differences in high risk factors between the two groups.The pancreatic spontaneous dislodgement stent safely prevented post-ERCP pancreatitis in high risk patients.CONCLUSION:Pancreatic stent placement is a safe and effective technique to prevent post-ERCP pancreatitis.Therefore authors recommend pancreatic stent placement after ERCP in high risk patients.     

Favorable response to subcutaneous administration of infliximab in rats with experimental colitis

AIM: To investigate the influence of infliximab (Remicade) on experimental colitis produced by 2,4,6,trinitrobenzene sulfonic acid (TNBS) in rats. METHODS: Thirty-six Wistar rats were allocated into four groups (three groups of six animals each and a fourth of 12 animals). Six more healthy animals served as normal controls (Group 5). Group 1: colitis was induced by intracolonic installation of 25 mg of TNBS dissolved in 0.25 mL of 50% ethanol and infliximab was subcutaneously administered at a dose of 5 mg/kg BW; Group 2: colitis was induced and infliximab was subcutaneously administered at a dose of 10 mg/kg BW; Group 3: colitis was induced and infliximab was subcutaneously administered at a dose of 15 mg/kg BW; Group 4: colitis was induced without treatment with infliximab. Infliximab was administered on d 2-6. On the 7~(th) d, all animals were killed. The colon was fixed in 10% buffered formalin and examined by light microscopy for the presence and activity of colitis and the extent of tissue damage. Tumor necrosis factor-alpha (TNF-α) and malondialdehyde (MDA) were also measured. RESULTS: Significant differences concerning the presence of reparable lesions and the extent of bowel mucosa without active inflammation in all groups of animals treated with infliximab compared with controls were found. Significant reduction of the tissue levels of TNF-α in all groups of treated animals as compared with the untreated ones was found (0.47±0.44, 1.09±0.86, 0.43±0.31 vs 18.73±10.53 respectively). Significant reduction in the tissue levels of MDA was noticed in group 1 as compared to group 4, as well as between groups 2 and 4. CONCLUSION: Subcutaneous administration of infliximab reduces the inflammatory activity as well as tissue TNF-α and MDA levels in chemical colitis in rats. Infliximab at a dose of 5 mg/kg BW achieves better histological results and produces higher reduction of the levels of TNF-α than at a dose of 10 mg/kg BW. Infliximab at a dose of 5 mg/kg BW produces higher reduction of tissue MDA levels than at a dose of 15 mg/ kg BW.     

Effect of melatonin on the severity of L-arginine-induced experimental acute pancreatitis in rats

AIM: To determine the effect of melatonin pre- and post-treatment on the severity of L-arginine (L-Arg) -induced experimental pancreatitis in rats. METHODS: Male Wistar rats (25) were divided into five groups. Those in group A received two injections of 3.2 g/kg body weight L-Arg i.p. at an interval of 1 h. In group MA, the rats were treated with 50 mg/kg body weight melatonin i.p. 30 min prior to L-Arg administration. In group AM, the rats received the same dose of melatonin 1 h after L-Arg was given. In group M, a single dose of melatonin was administered as described previously. In group C the control animals received physiological saline injections i.p. All rats were exsanguinated 24 h after the second L-Arg injection. RESULTS: L-Arg administration caused severe necrotizing pancreatitis confirmed by the significant elevations in the serum amylase level, the pancreatic weight/body weight ratio (pw/bw), the pancreatic IL-6 content and the myeloperoxidase activity, relative to the control values. Elevation of the serum amylase level was significantly reduced in rats given melatonin following L-Arg compared to rats injected with L-Arg only. The activities of the pancreatic antioxidant enzymes (Cu/Zn-superoxide dismutase (Cu/Zn-SOD) and catalase (CAT)) were significantly increased 24 h after pancreatitis induction. Mela- tonin given in advance of L-Arg significantly reduced the pancreatic CAT activity relative to that in the rats treated with L-Arg alone. In the liver, L-Arg significantly increased the lipid peroxidation level, and the glutathione peroxi-dase and Cu/Zn-SOD activities, whereas the Mn-SOD activity was reduced as compared to the control rats. Melatonin pre-treatment prevented these changes. CONCLUSION: Melatonin is an antioxidant that is able to counteract some of the L-Arg-induced changes during acute pancreatitis, and may therefore be helpful in the supportive therapy of patients with acute necrotizing pancreatitis.