Experimental acute pancreatitis in rats after chronic and chronic plus acute ethanol administration in combination with a pancreatic juice edema

The influence of long-term (26 weeks) and long-term plus acute ethanol administration on the development of acute pancreatitis was studied in rats. While both these treatments alone did not induce pancreatitis in any rat, extrapancreatic fat necrosis and histologic lesions of the pancreas were found in the majority of animal 24 hours after additional establishing of a pancreatic juice edema by an obstruction/hypersecretion mechanism. Severity and frequency of findings were significantly increased by additional short-term ischemia (25 min) of the pancreas. In control rats without ethanol ingestion, the edema receded without any lesions, and after additional ischemia significantly fewer rats exhibited signs of acute pancreatitis when compared to the ethanol-treated groups. An experimental model of acute alcoholic pancreatitis is presented with ethanol ingestion, temporary ductal obstruction and stimulation of secretion being essential constituents, which may be of clinical relevance, too.     

Does somatostatin analogue prevent experimental acute pancreatitis?

Because somatostatin is a potent inhibitor of pancreatic secretion, we hypothesized that pretreatment with somatostatin analogue octreotide (SMS 201-995) might prevent cerulein-induced edematous pancreatitis. We studied 18 rats prepared with jugular vein catheters. The following agents were administered intravenously to groups of four rats for 6 hours: 1 mL/h (control) crystalloid solution; 1-microgram/kg bolus then 1 microgram/kg per hour of octreotide; and 5 micrograms/kg per hour of cerulein; also, in a fourth group of six rats, octreotide and cerulein were administered simultaneously. At the end of experiments, blood was drawn for plasma amylase determinations; rats were killed and pancreata were examined. Supramaximal cerulein administration to conscious rats induced hyperamylasemia and edematous pancreatitis, confirming previous observations; in both groups of rats receiving cerulein, there was prominent interstitial edema, acinar vacuolization, and mild-to-moderate acute inflammation. While octreotide pretreatment of rats with cerulein-induced acute pancreatitis was associated with a lesser increase of wet pancreas weight and plasma amylase concentration, there was little overall benefit of octreotide pretreatment in this form of experimental acute pancreatitis.     

Effects of timing of diatrizoate (water-soluble contrast medium) administration on pancreatic microcirculatory derangement in cerulein pancreatitis in rats

OBJECTIVE: We investigated whether the timing of administration of contrast medium after onset of acute pancreatitis is critical in determining the magnitude of microcirculatory derangement. METHODS: An acute pancreatitis model in male Sprague-Dawley rats (225-275 g) was established by continuous infusion of cerulein (15 mg/kg per hour). The mean arterial pressure was monitored continuously by means of a femoral artery catheter. Diatrizoate (Hypaque-76), a water-soluble contrast medium, was delivered through a femoral vein catheter at doses corresponding to those given to humans, either 1, 2, or 3 hours after pancreatitis induction. In vivo microscopy and laser-Doppler flowmetry were used to investigate microcirculatory derangement. The water contents of the pancreas and lung, the malondialdehyde levels of the pancreas, and the trypsinogen activation peptide levels in the serum were measured at the end of the experiment (8 hours after infusion of cerulein). RESULTS: Early administration of contrast medium (1 hour after pancreatitis induction) resulted in significantly greater changes in microcirculation and mean arterial pressure than did late administration (2 or 3 hours after pancreatitis induction). Rats given contrast medium 1 hour after induction also had highest pancreas and lung water contents, the highest pancreas malondialdehyde levels, and the highest serum trypsinogen activation peptide levels. CONCLUSION: These results show that a water soluble contrast medium that is often used for computed tomographic imaging of the pancreas can adversely affect the pancreatic microcirculatory parameters, such as tissue perfusion and leukocyte sticking, and hemodynamics in a cerulein-induced model of acute pancreatitis. Early administration seems to cause more severe derangement of the pancreatic microcirculation.     

Pancreatic microcirculation in acute pancreatitis of dogs

Pancreatic microcirculation in acute pancreatitis and the effect of dopamine and pancreatic protease inhibitor were investigated in 35 mongrel dogs. Acute pancreatitis was induced by the injection of autologous bile added trypsin into pancreatic duct. In acute pancreatitis dogs femoral artery pressure and pulse pressure gradually decreased and pancreatic microflow in basal state temporarily increased immediately after bile injection, however, thereafter continuously decreased during the experiments. Portal flow severely decreased just after onset of acute pancreatitis. By administration of dopamine femoral artery pressure was maintained during the first 90 minutes of experiments, however, thereafter decreased until the end of experiments. Pancreatic microflow, 56.1 +/- 15.3 ml/min/100g in basal level was shown 66.1 +/- 13.7 and 60.3 +/- 10.3 ml/min/100g at 1 and 2 hours, respectively, after bile injection, which were significantly high values as compared with those of non dopamine administration. However those values decreased at 5 hours of both experiments. Portal flow whose basal level was 237 +/- 67 ml/min was maintained during the first 1 hour however it decreased to 139 +/- 25 ml/min at 5 hours. By administration of pancreatic protease inhibitor femoral artery pressure and pulse pressure, temporarily decreased immediately after bile injection, however, they were maintained thereafter. Pancreatic microflow, 57.1 +/- 18.3 ml/min/100g in basal level, was maintained during the first 2 hours, however significantly decreased to 27.6 +/- 9.7 ml/min/100g at 5 hours. Portal flow significantly increased to 442 +/- 115 ml/min at 2 hours, however, thereafter decreased 219 +/- 93 ml/min at 5 hours.(ABSTRACT TRUNCATED AT 250 WORDS)     

Secretion of beta-lactam antibiotics in pure human pancreatic juice

The secretion of cephalothin and cefoxitin in stimulated pure pancreatic juice was studied in 13 persons after intravenous administration of antibiotics. Of all these studied, three had acute relapsing pancreatitis, five chronic pancreatitis, and five were control subjects. Antibiotic levels were measured in paired pure pancreatic juice and serum samples at fixed time intervals after administration. Cephalothin was detected in very low levels (1 to 1.8 micrograms/ml) in the pure pancreatic juice of four of the six persons studied (3 micrograms/ml). Although therapeutic levels were not obtained in stimulated pure pancreatic juice with either antibiotic, additional studies evaluating antibiotic levels in unstimulated pure pancreatic juice and in pancreatic tissue would be helpful in assessing the role of antibiotic therapy in the treatment of pancreatitis.     

Frequency and time course of pancreatic and extrapancreatic bacterial infection in experimental acute pancreatitis in rats

BACKGROUND: Infectious complications in severe pancreatitis are the main factors determining clinical course and outcome. The taurocholate model for acute necrotizing pancreatitis was evaluated for frequency and time course of pancreatic and extrapancreatic bacterial infection. METHODS: Sixty-five male Wistar rats were divided into 5 groups of 13 animals each. Specimens for bacteriologic examination were taken, and pancreatitis was induced by intraductal infusion of 3% taurocholate under sterile conditions. Animals were killed 8, 16, 24, or 32 hours thereafter, and bacteriologic examination was performed. A control group of animals with intraductal infusion of 0.9% saline solution were killed after 32 hours. RESULTS: There was no significant pancreatic infection in the control group and in the 8-hour group (1 of 13 rats). Sixteen and 24 hours after induction of pancreatitis, infection and inflammation of the pancreas were found in 77% (10 of 13 rats), and after 32 hours pancreatic infection occurred in 69% (9 of 13 rats). Extrapancreatic bacterial infection after 16 hours occurred in the liver (62%), spleen (62%), and mesenteric lymph nodes (46%). Bacteria infecting the pancreas reflected the bacterial spectrum of the large bowel and terminal ileum before induction of pancreatitis (Escherichia coli [77%], Proteus [43%], Enterococcus [37%], and Staphylococcus [23%]). CONCLUSIONS: Pancreatic infection is an early and frequent finding in the taurocholate model of acute necrotizing pancreatitis. Infection occurs between 8 and 16 hours after induction of pancreatitis. The source of infecting bacteria seems to be the large bowel or the terminal ileum. We present a useful model of severe pancreatitis in which to study bacterial translocation, the further route of spread, and therapeutic approaches.     

急性胰腺炎大鼠TNF-α mRNA、IL-10 mRNA表达和胰腺细胞凋亡的研究

目的 探讨大鼠急性胰腺炎早期胰腺组织中TNF－αmRNA、IL－10mRNA的表达和细胞凋亡的变化规律。方法 以牛磺胆酸钠诱导20只大鼠急性水肿性胰腺炎（AEP）模型,20只急性坏死性胰腺炎（ANP）模型,另取10只正常大鼠作为对照。术后12h各处死10只大鼠,检测血清和胰腺组织中的TNF－α和IL－10水平,分析两者在胰腺组织中的mRNA较录水平,检测胰腺细胞的凋亡率。结果 正常、AEP和ANP组的细胞凋亡率分别为2．98％、17．29％和8．39％。制模后TNF－αm和IL－10增强ANP大鼠TNF－α表达增强。结论 急性胰腺炎大鼠胰腺组织中的TNF－α和IL－10的表达与其在血清和胰腺中的浓度成正比,胰腺本身可能就是产生细胞因子的主要器官。胰腺细胞凋亡率与疾病的严重程度呈负相关,凋亡是对胰腺损伤的良好反应。     

Calcitonin gene-related peptide partially mediates nociception in acute experimental pancreatitis

BACKGROUND: The mechanism by which pancreatitis causes pain is unknown. The neuropeptide calcitonin gene-related peptide (CGRP) is released after sensory nerve activation and promotes nociceptive signaling in models of visceral pain. We hypothesized that acute pancreatitis leads to the activation of pancreatic sensory neurons that release CGRP in the dorsal horn of the spinal cord. This signal is ultimately transmitted to the brain, and pain is sensed. METHODS: To induce pancreatitis, rats were injected with l-arginine (500 mg/kg) intraperitoneally or saline (control). Pancreatitis was confirmed by measuring serum amylase and evaluating pancreatic histology. Activation of nociceptive pathways was evaluated by counting Fos-like immunoreactive nuclei (FLI) in the dorsal horn of the spinal cord at T3-L1. Some animals received the CGRP antagonist CGRP(8-37) (50 microg intrathecally) 2 hours before perfusion. Animals were compared using a 2-tailed t test. RESULTS: l-Arginine treatment induced acute necrotizing pancreatitis in the rat at 24 hours. l-Arginine (24 hours) increased FLI in the dorsal horn of the spinal cord, with a peak effect at L1. Intrathecal administration of CGRP(8-37) significantly decreased the number of FLI nuclei in the dorsal horn of the spinal cord in T11-L1. CONCLUSIONS: Nociception in the l-arginine model of acute pancreatitis is partially mediated by the release of CGRP in the dorsal horn of the spinal cord. Antagonism of CGRP or its receptors may be useful in treating pain from acute pancreatitis.     

Use of ribonuclease in multimodal treatment of acute pancreatitis

The method of intraductal administration of ribonuclease as a therapeutic measure was developed on an experimental model of acute pancreatitis in albino rats. Morphological and biochemical examination showed that intraductal administration of ribonuclease in a dose of 0.5 mg produces a positive therapeutic effect, which allowed the method to be applied in complex treatment of 33 patients with various forms of acute pancreatitis. Administration of ribonuclease into the pancreatic duct relieved the attack of pain and reduced the level of lipo- and proteolytic enzymes in blood. No complications were encountered in endoscopic cannulation of the main pancreatic duct and subsequent administration of ribonuclease.     

不同剂量坎地沙坦治疗大鼠急性胰腺炎的实验研究

目的：探讨选择性血管紧张素Ⅱ受体亚型AT1拮抗剂坎地沙坦不同剂量对大鼠急性胰腺炎（AP）的影响。方法：72只雄性SD大鼠随机分为正常对照组、AP组、AP＋低剂量坎地沙坦组（2 mg/kg）、AP＋高剂量坎地沙坦组（10 mg/kg）。腹腔注射20%L-精氨酸溶液建立AP动物模型;坎地沙坦用大鼠灌胃针灌注。各组大鼠分别在造模后12 h、24 h、48 h分批次等数量（6只/组/批）心脏取血处死。取胰腺组织观察胰腺病理变化并评分（按Rongione标准）,胰腺/体质量比,检测大鼠血清脂肪酶、TNF-α、IL-10的变化。结果：AP组胰腺炎症评分,胰腺/体质量比,血清脂肪酶、TNF-αI、L-10较对照组明显升高（P〈0.01）。其中胰腺/体质量比于造模后12 h已有明显升高,于48 h达到高峰;而血清脂肪酶和胰腺TNF-αI、L-10于造模后12 h达到高峰,此后有所下降,但仍然保持较高水平。坎地沙坦干预的实验组胰腺炎症评分,胰腺/体质量比,血清脂肪酶、TNF-α以及胰腺TNF-α较AP组降低（P〈0.05）,但低剂量坎地沙坦组与高剂量组间无显著差异（P〉0.05）。本实验中,应用坎地沙坦对AP大鼠血清及胰腺IL-10均无显著影响（P〉0.05）。结论：应用AT1受体拮抗剂坎地沙坦可以明显减轻L-精氨酸诱导大鼠急性胰腺炎的炎症及损伤。     

Possible role of cholecystokinin in the development of acute pancreatitis in rats

The aim of this study was to elucidate whether cholecystokinin (CCK) had a role in the occurrence and/or in the development of experimental acute pancreatitis in rats, and furthermore to find the possibility for the treatment of acute pancreatitis with a CCK antagonist, proglumide. The administration of CCK-8 significantly increased serum levels of amylase, lipase and pancreatic wet weight. The administration of proglumide significantly reduced the blood levels of trypsin, pancreatic wet weight, water content and improved survival rate. These findings were supported by microscopic examination. The results of this study demonstrate that CCK has an important role in the development of acute pancreatitis and that proglumide might have prophylactic and therapeutic effects in acute pancreatitis.     

肝素联合胰岛素治疗高甘油三酯血症相关急性重症胰腺炎1例

目的：报道一例静脉联合肝素治疗高甘油三酯血症相关急性重症胰腺炎的病例,并复习相关文献。内容：一例急性重症胰腺炎（急性生理和慢性健康评分Ⅱ20分。Ranson评分6分）的孕妇患者来我院就诊。留取静脉血标本时发现明显脂血,总甘油三酯85．07mmol／L,诊断考虑高甘油三酯血症相关急性重症胰腺炎。在治疗过程中除常规的水化,抗感染和抑制胰酶分泌治疗外,通过静脉肝素联合胰岛素泵入,于24小时后将甘油三酯降至15．80mmol／L,并于72小时后将甘油三酯降低至3．68mmol／L,从而控制了病情的进展。本文对有关文献进行了综述。结论：肝素联合胰岛素静脉泵入治疗可以在短时间内有效降低高甘油三酯血症相关急性重症胰腺炎患者的血清甘油三酯水平,有可能成为一种在该类患者中替代血浆置换的治疗手段。     

Acute hemorrhagic pancreatitis in the dog. 5. The effect of antidiuretic hormone on pancreatic exocrine secretion

Acute hemorrhagic pancreatitis was created in dogs using the closed duodenal loop technique. After 18 hours, a a constant rate of pancreatic exocrine secretion was stimulated with secretin. A direct relationship was observed between the percentage inhibition of secretin-stimulated pancreatic exocrine flow and the dose of antidiuretic hormone administered to dogs with acute hemorrhagic pancreatitis. The acute hemorrhagic pancreatitis reduced the sensitivity of the exocrine pancreas to secretin and antidiuretic hormone.     

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.     

The relative safety of MRI contrast agent in acute necrotizing pancreatitis.

OBJECTIVE: To validate the safety of gadolinium-diethylenetriamine pentaacetic acid (GD-DTPA) by measuring its effect on pancreatic capillary perfusion and acinar injury in acute pancreatitis. BACKGROUND: Contrast-enhanced computed tomography (CECT) is proposed as a gold standard for early evaluation of acute necrotizing pancreatitis. However, iodinated contrast media used for CECT have been shown in these circumstances to reduce pancreatic capillary flow and increase necrosis and mortality. Recent reports suggest that post-GD MRI provides images comparable to CECT in the assessment of severe acute pancreatitis. METHODS: Necrotizing pancreatitis was induced in 14 Wistar rats by intraductal glycodeoxycholic acid (10 mM/L) and intravenous caerulein (5 microg/kg/h) over 6 hours. Intravital microscopic quantitation of pancreatic capillary blood flow was performed using fluorescein isothiocyanate-labeled erythrocytes after induction of pancreatitis and 30 and 60 minutes after an intravenous bolus of either Ringer's solution or GD-DTPA (0.2 mL/kg). RESULTS: The two study groups were comparable with regard to mean arterial pressure, heart rate, arterial blood gases, hematocrit, amylase, lipase, and trypsinogen activation peptide production throughout the experiment. GD-DTPA did not reduce capillary flow (1.93 +/- 0.05 nL/capillary/min) compared to animals infused with Ringer's solution (1.90 +/- 0.06 nL/capillary/min). CONCLUSIONS: Intravenous injection of GD-DTPA does not further impair pancreatic microcirculation or increase acinar injury in acute necrotizing pancreatitis. Because of this advantage over CT contrast medium, further development of MRI as a staging tool in acute pancreatitis seems desirable.     

Effect of short-term-ischemia and reperfusion on the rat pancreas]

In order to examine the toxic effects on the pancreas of oxygen free radicals which are generated at reperfusion after ischemia, a short term-ischemia/reperfusion model was prepared in rats. Both the anterior mesenteric artery and the celiac artery were ligated and then released to restore blood flow. In a group where the anterior mesenteric and the celiac arteries were ligated for 60 minutes, the serum levels of amylase and lipase rose 7 and 6 times, respectively, 7 hours after reperfusion. In a group ligated for 30 minutes, both levels remained unchanged. Histologically, vacuolization of the pancreatic acinar cells was observed, only in a group rats ischemic for 7 hours. In rats ligated for 60 minutes with a continuous venous infusion of superoxide dismutase (SOD) (3600 U/Kg/hour), the secretion of amylase and lipase decreased to 25 percent of that in the non-injected group. These results confirm that the oxygen free radicals, which are generated by the short term-ischemia/reperfusion method, injure the pancreas. This may lead to pancreatitis with hyperamylasemia and hyperlipasemia. Pretreatment with an active oxygen scavenger, SOD, markedly reduces the rise in serum amylase and lipase levels. This suggests that active oxygen free radicals are involved in the pathogenesis of acute pancreatitis.     

大承气汤对急性重型胰腺炎大鼠血中可溶性粘附分子CD11a/CD1 8表达的影响

目的：进一步认识大承气汤对急性胰腺炎的治疗机理。方法：采用胰管内逆行注入牛磺胆酸钠方法造成大鼠急性重型胰腺炎模型,造模后用大承气汤、生理盐水进行治疗,观察造模治疗后12h、14h动物血清中CD11a/CD18、淀粉酶及胰腺组织中TNF含量的变化和胰腺组织病理学的改变。结果：应用大承气汤治疗组的大鼠血中的可溶性CD11a/CD18表达胰腺组织中的TNF含量、胰腺组织病理损害程度、胰酶血症的水平均较生理盐水治疗组明显下降或减轻。结论：认为大承气汤治疗急性重型胰腺炎的机理可能不仅在于其能促进胰酶的排出,还与其减少粘附分子CD11a/CD18的表达,减少胰腺组织中PMNs的浸润程度,进而减轻了胰腺组织损伤有关。     

Effect of platelet-activating factor antagonists (BN-52021, WEB-2170, and BB-882) on bacterial translocation in acute pancreatitis

Bacterial translocation is an important source of pancreas infection in acute pancreatitis. The effect of platelet-activating factor (PAF) in the pathogenesis of acute pancreatitis has been proved in various studies. The aim of this study was to determine whether potent PAF antagonists influence bacterial translocation in acute pancreatitis. Acute pancreatitis was induced in 62 Wistar rats by injection of 2.5% sodium taurocholate into the biliopancreatic duct. The rats treated with PAF factor antagonists received intravenous injection of WEB-2170 (10 mg/kg), lexipafant (5 mg/kg), and BN-52021 (5 mg/kg) 30 minutes before induction of acute pancreatitis. Six hours after induction of acute pancreatitis, bacteriologic cultures and histologic scoring of tissues were performed. There was a statistically significant reduction in bacterial translocation to the mesenteric lymph nodes and liver but not to the pancreas of the rats treated with PAF antagonists. No significant increase in the intestinal bacterial population of any group was found. There were no statistical differences between the pancreatic histologic scores of the groups. PAF antagonists reduced bacterial translocation to distant sites other than the pancreas, preventing the bacterial dissemination that occurs in the early phase of acute pancreatitis and may have beneficial effects on the evolution of this disease.     

Macrophage ablation attenuates adenoviral vector-induced pancreatitis

BACKGROUND: The objective of these studies is to determine the effects of macrophage ablation on the course of acute viral pancreatitis. Macrophages secrete proinflammatory cytokines triggering local pancreatic and systemic inflammation in the acute phase of virus-induced pancreatitis. We hypothesized that ablation of macrophages should attenuate the host inflammatory response in a mouse model of adenovirus-induced pancreatitis. METHODS: Liposome-encapsulated dichloromethylene-diphosphonate, a macrophage-depleting agent, was used before direct pancreatic injection of a recombinant adenovirus expressing a marker gene in C57Bl/6 and IL-6 knockout (KO) mice. RESULTS: C57Bl/6 mice depleted of macrophages had diminished pancreatic inflammation in the first 24 hours after vector administration. IL-6 KO mice depleted of macrophages had more severe inflammation than similarly treated C57Bl/6 mice. C57Bl/6 mice depleted of macrophages, and IL-6 KO mice had prolonged transgene expression and diminished cytotoxic T lymphocyte responses to adenoviral vector. Mortality was highest in IL-6 KO mice depleted of macrophages. Depletion of macrophages also prevented detectable serum IL-6, IL-10, or IL-12 levels in C57Bl/6 mice. CONCLUSIONS: The data suggest that macrophages play a role in the acute inflammatory response to viral vector-induced pancreatitis and that IL-6 may be protective. Understanding of the mechanisms that initiate the host immune cascade will allow more effective use of adenoviral vector-based pancreatic gene delivery.     

Pancreatic tissue perfusion in experimental acute pancreatitis.

OBJECTIVE: To investigate pancreatic tissue perfusion and oxygenation in severe and mild experimental acute pancreatitis in pigs. DESIGN: Randomised controlled experiment. SETTING: Animal laboratory, Finland. ANIMALS: 24 domestic pigs weighing 21-27 kg. INTERVENTIONS: 24 pigs were randomised into severe acute pancreatitis, mild acute pancreatitis and control groups (n = 8 in each). The pancreatic duct of eight anaesthetised and mechanically ventilated pigs was cannulated and taurocholic acid was infused into the pancreatic duct to induce severe acute pancreatitis. Eight animals received intraductally infused saline and developed mild acute pancreatitis. Eight pigs had their ducts cannulated alone, and served as controls. MAIN OUTCOME MEASURES: Pancreatic tissue oxygenation, laser Doppler red cell flux, central haemodynamics. RESULTS: Intraductally infused taurocholic acid rapidly induced macroscopically and histologically proven severe necrotising acute pancreatitis. Histological changes characterising mild acute pancreatitis were seen in animals after intraductal saline infusion. Pancreatic tissue oxygen tension decreased in the severe group and increased in the mild group during the six-hour study period. Laser Doppler red cell flux decreased in the severe group. Central haemodynamics, arterial blood gases, and acid base balances were stable throughout the study period in all groups. CONCLUSION: The present model of severe acute pancreatitis significantly impairs pancreatic oxygenation in the early phase. In mild acute pancreatitis, pancreatic oxygenation increases.