Experimental acute pancreatitis in the rat. The quantification of pancreatic necrosis after the retrograde ductal injection of sodium taurocholate]

Acute haemorrhagic pancreatitis was induced in rats by injecting 5% sodium taurocholate into the common biliopancreatic duct. The condition was associated with an increase in the serum amylase levels as well as progressive pancreatic necrosis resulting in 100% mortality before 36 hours. This experimental model was documented by quantifying nine different parameters of pancreatic necrosis and giving more information about the induced lesion. The extent of pancreatic necrosis was evaluated at different intervals, 5.77% at 12 hours, 14.9% at 24 hours, and the rats died before 36 hours of pancreatitis induction with an average percentual necrosis of 29.9%. This model seems suitable for more pathogenic as well as therapeutic studies on acute pancreatitis in the rat.     

大鼠ERCP术后胰腺炎模型的建立及意义

目的建立内镜逆行胰胆管造影(ERCP)术后胰腺炎大鼠模型．并与牛黄胆酸所诱发胰腺炎模型进行对照．为研究药物预防ERCP术后胰腺炎提供实验和理论依据。方法16只SD大鼠随机分为3组，实验组(6只)：以恒定压力(50mmHg)胰胆管注射30％泛影葡胺持续2min：对照组(6只)：按0．1m1／100g．0．2ml／min速度用微量推射泵在胰胆管内注入5％牛磺胆酸；假手术组(4只)：打开腹腔翻动胰腺后关腹。24h后开腹取胰腺组织作病理学检查，并检测血淀粉酶。结果24h后实验组及对照组胰腺与假手术组比较不论在大体病理，还是组织学病理的变化上均有显著差异，实验组和对照组血清淀粉酶也显著高于假手术组，而实验组和对照组差异不显著。结论恒定压力下胰胆管注射泛影葡胺建立的大鼠胰腺炎模型模拟了人ERCP术后胰腺炎过程，而且与牛黄胆酸所诱导的胰腺炎模型有类似的病理和淀粉酶变化，为研究预防ERCP术后胰腺炎的发生打下了基础。     

Pancreatic and bile duct obstruction exacerbates rat caerulein-induced pancreatitis: a new experimental model of acute hemorrhagic pancreatitis

Background Pancreatic duct obstruction induces edematous but not hemorrhagic pancreatitis even when combined with maximal secretory stimulation. The aim of the present study was to test the hypothesis that pancreatic and bile duct obstruction exacerbates edematous pancreatitis induced by supramaximal secretory stimulation by caerulein. Methods In in vivo studies using rats, biliopancreatic duct ligation was combined with supramaximal stimulation of caerulein, and pancreatic histology, serum amylase level, pancreatic edema, and intrapancreatic trypsin activation were evaluated. In in vitro studies, the pancreatic acini were isolated from the rats with biliopancreatic duct ligation, and amylase secretion, intracellular trypsin activation, and acinar cell fragility were evaluated. Results Biliopancreatic duct ligation exacerbated caerulein-induced pancreatitis from edematous to hemorrhagic only when the obstruction preceded caerulein administration. The amylase secretion from the acini was inhibited, and intracellular trypsin activation and the acinar cell fragility on the supramaximal stimulation with cholecystokinin in vitro were enhanced by the preceding in vivo biliopancreatic duct obstruction. Conclusions Preceding biliopancreatic duct obstruction exacerbates caerulein-induced pancreatitis. Enhancement of intracellular trypsin activation is possibly involved in this mechanism.     

Beneficial effect of octreotide treatment in acute pancreatitis in rats

Summary Conclusions Octreotide treatment contributes to the regulation of tumor necrosis factor (TNF) production in sodium taurocholate-induced acute necrotizing pancreatitis in rats. Owing to its complex effect, octreotide can partially ameliorate the deleterious consequences of acute necrotizing pancreatitis. Elevated TNF and interleukin-6 (IL-6) levels in the peritoneal fluid may be considered a consequence of the activation of peritoneal macrophages. Background The effects of octreotide on exocrine pancreatic function have been investigated in numerous studies, but little attention has been paid to its influence on cytokine production in acute pancreatitis. Methods Acute pancreatitis was induced by the retrograde injection of taurocholic acid into the pancreatic duct in male Wistar rats. Serum amylase activity, wet pancreatic weight/body weight (pw/bw) ratio, and TNF and IL-6 levels were measured. Four μg/kg of octreotide was administered subcutaneously at the time of induction of pancreatitis and 24 or 48 h later. Rats were sacrificed 6, 24, 48, or 72 h after the operation. Results The serum amylase level and pancreatic weight to body weight ratio were decreased significantly in the octreotide-treated group. The serum TNF level was decreased significantly in the octreotide-treated group as compared with the control group at 6, 24, and 48 h (0.6±1.5, 2.0±3.3, and 0 vs. 50±15.5, 37.5 ±18.4, and 13.1±12.5 U/mL, respectively). The ascites TNF level was decreased to 0 in the octreotide-treated group and was elevated in the control group at 72 h (28.0±49.0 U/mL). IL-6 production in ascites was extremely high in both groups at 6 h (80,000±43, 817 pg/mL and 58, 500±33 335 pg/mL), but the difference was not significant.     

Somatostatin in the treatment of established and severe acute pancreatitis in the rat]

The effects of somatostatin (SS) on the treatment of acute pancreatitis were studied in rats. Acute pancreatitis was established by injecting 5% sodium taurocholate in the biliopancreatic duct. Previously, pancreatic necrosis was determined in this experimental model at several intervals without treatment. Treatment was started according different groups: at 12, 16 and 20 hours after induction of acute pancreatitis (IV bolus of 4 ug/kg body weight followed by a 24h continuous infusion of 4 ug/kg body wt/hour). When somatostatin was initiated at 12 or 16h a decrease in serum amylase and lactodehydrogenase was observed, as well as in pancreatic necrosis resulting in 0% mortality after 24h of treatment. When somatostatin was started at 20h there was no changes in the lethal outcome of the disease.     

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.     

血必净对大鼠重症急性胰腺炎的治疗作用

目的:探讨血必净对大鼠重症胰腺炎(severe acute pancreatitis,SAP)的治疗作用.方法:经十二指肠乳头逆行胆胰管注射3.5％牛磺胆酸钠建立SAP模型,给予血必净治疗,观察血清中淀粉酶含量、白介素-6(interleukin-6,IL-6)、丙二醛(malondialdehyde,MDA)、超氧化...     

Role of Ghrelin and Leptin in Predicting the Severity of Acute Pancreatitis

Ghrelin and leptin are the hormones that influence endocrine and exocrine functions of the pancreas and regulate feeding behaviors and energy metabolism. The aim of this study was to investigate the levels of ghrelin and leptin in pancreatitis of different severities and the relation of these hormones with blood glucose level and proinflammatory cytokines. The study was performed on 90 Wistar Albino rats. Three experimental groups composed of 30 rats were established: control group, 0.9% NaCl solution was injected intraperitoneally (i.p); acute edematous pancreatitis (AEP) group, 1 μg/100 g cerulein was injected i.p. five times, at 1-hr intervals; and acute necrotizing pancreatitis (ANP) group, 500 mg/100 g l-arginine was injected i.p. Ten animals in each group were sacrificed under anesthesia 12, 24 and 48 hr after the last injection. After blood withdrawal, the pancreas was totally excised. The levels of blood sugar, lipase, serum tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), ghrelin, and leptin were investigated and histopathologic examination was performed. Following pancreatitis induction, serum ghrelin levels increased at 24 hr and reached the peak level at 48 hr. Its level in the AEP group was higher than in the ANP group. Serum leptin levels in the AEP and ANP groups increased after 12 hr and stayed at high levels until 48 hr compared with the control group. Similarly to ghrelin and leptin, blood glucose levels increased in both pancreatitis groups, but the increase was more prominent in the ANP group, with levels >200 mg/ml at 48 hr. The levels of TNF-α and IL-1β in the AEP and ANP groups reached the peak level at 24 hr and then decreased to a level close to that of the control group at 48 hr. We conclude that serum leptin and ghrelin levels increase in the first 48 hr of AEP and ANP. As the serum ghrelin levels in ANP are higher than in AEP, it can be used as a marker to show the severity of pancreatitis. While TNF-α and IL-1β can be used as a prognostic factor in the first 24 hr, ghrelin and leptin can be used subsequently.     

Biliopancreatic fistula with portal vein thrombosis caused by a pancreatic pseudocyst

We encountered a very rare case of biliopancreatic fistula with portal vein thrombosis caused by pancreatic pseudocyst. A 57-year-old man was referred to our hospital because of abdominal pain, obstructive jaundice, and portal vein thrombosis due to acute pancreatitis. Computed tomography showed a 7-cm-diameter pseudocyst around the superior mesenteric vein extending towards the pancreatic head, dilatation of the intrahepatic bile duct, and portal vein thrombosis. Endoscopic retrograde pancreatography revealed a main pancreatic duct with a pseudocyst communicating with the common bile duct. After pancreatic sphincterotomy, a 7-F tube stent was endoscopically placed into the pseudocyst. However, a 6-F nasobiliary tube could not be inserted into the bile duct because the fistula had a tight stenosis. Subsequently, the patient’s abdominal pain improved, the pancreatic cyst disappeared, and the serum amylase level normalized. Two months after the endoscopic retrograde cholangiopancreatography, percutaneous transhepatic biliary drainage was required because the patient’s jaundice became aggravated. Two weeks after the choledochojejunostomy, the patient left the hospital in good condition. A follow-up computed tomography showed cavernous transformation of the portal vein and no pancreatic pseudocyst. The patient remains asymptomatic for 2 years and 7 months after surgery. Biliary drainage may be necessary for biliopancreatic fistula with obstructive jaundice in addition to pancreatic cyst drainage. Biliopancreatic fistula can be treated by endoscopic procedure in some cases; however, surgical treatment should be required in cases that are impossible to insert a biliary stent because of hard stricture.     

Early prediction of intestinal mucosal barrier function impairment by elevated serum procalcitonin in rats with severe acute pancreatitis

ObjectivesThe aim of this study was to evaluate serum procalcitonin (PCT) levels as a prognostic indicator of intestinal barrier function impairment in rats with severe acute pancreatitis (SAP).MethodsThirty-six male Sprague Dawley rats were randomly grouped into SAP group (injected sodium taurocholate via biliopancreatic duct), Gln group (gavaged with glutamine after modeling), and control group. Blood, pancreatic, and terminal ileum tissues were obtained from the rats after 6 h of modeling. Serum amylase (Amy) levels were determined using an automatic biochemical detector, while endotoxin (ET), diamine oxidase (DAO), and PCT levels were measured by ELISA test. The pathology of pancreatic and small intestine tissues were observed. PCT protein expression in intestinal tissues were detected by immunohistochemistry and western blot.ResultPancreatic and intestinal injuries in Gln group were significantly lower than SAP group. Serum amylase, DAO, and PCT levels in SAP and Gln groups differed greatly and were significantly higher than control group. Immuno-histochemistry and western blot results showed that PCT protein expression levels in small intestine tissues of SAP group were higher than Gln group and control group. Serum PCT levels had a significant correlation with serum endotoxin, DAO levels and intestinal mucosal injury scores.ConclusionPCT expression in serum and intestinal tissues in SAP rats increased significantly in the early stages of SAP, and was closely related to the onset and degree of intestinal barrier function impairment. Thus, our results showed that measuring serum PCT can be used to predict intestinal mucosal barrier function impairment in SAP rats.     

TNF-α acutely upregulates amylin expression in murine pancreatic beta cells

Aims/hypothesis  

Amylin, a secretory protein mainly produced by pancreatic beta cells, is elevated in the circulation of patients with diseases related to acute and chronic inflammation, including acute pancreatitis, pancreas graft rejection, obesity and insulin resistance. TNF-α is involved in these disorders. We investigated the effect of TNF-α on amylin levels and the underlying mechanisms, using murine pancreatic beta cell line MIN6 and pancreatic islets.     

抗氧化剂对大鼠重症急性胰腺炎胰腺腺泡细胞凋亡的影响

目的探讨四氢化吡咯二硫代氨基甲酸酯（PDTC）对重症急性胰腺炎（SAP）胰腺腺泡细胞凋亡的影响。方法SD大鼠72只，随机分为：假手术组（sham operation，SO）、SAP组和PDTC组。SAP模型采用5％牛磺胆酸钠1ml/kg胰胆管逆行穿刺注射建立，PDTC组在造模前1h给予腹腔注射PDTC（1130mg/kg），术后分4个时段（1、3、6、12h）分批进行腹主动脉采血后处死，取胰腺组织作病理切片与液氮冻存。胰腺腺泡细胞的凋亡检测应用TUNEL法、电镜以及免疫组化法检测胰腺组织Caspase-3的表达；核因子（NF）-κB活化的检测应用免疫组化法。同时观察各组血清淀粉酶、脂肪酶水平及胰腺组织病理学评分。结果SAP组各时间点血清淀粉酶及脂肪酶水平及胰腺组织病理组织学评分较SO组显著增高（P〈0．05）。PDTC治疗组血清淀粉酶、脂肪酶水平较SAP组明显降低；胰腺组织病理组织学评分明显改善。PDTC治疗后3、6、12h胰腺组织Caspase-3的表达显著高于SAP组（P〈0．01），而在1h无统计学差异；各时间点胰腺腺泡细胞凋广指数显著高于SAP组（P〈0．01）；NF—κB的活化显著低于SAP组（P〈0．01）。结论SAP时，PDTC可能通过抑制NF—κB的活化，从而抑制NF—κB介导胰腺细胞的抗凋亡效应，减少胰腺腺泡细胞坏死。     

Melatonin ameliorates acute necrotizing pancreatitis by the regulation of cytosolic Ca2+ homeostasis

ObjectivesThis study aims to investigate the relationship between the protective effects of melatonin in pancreas and the expression of sarco/endoplasmic reticulum Ca²⁺-ATPase (SERCA) and Na⁺/Ca²⁺ exchanger (NCX) in rats with acute necrotizing pancreatitis (ANP), to verify whether melatonin ameliorates ANP by alleviating calcium overload.MethodsNinety-six male Sprague-Dawley rats were randomly divided into four groups (sham operation group, ANP group, melatonin treatment group, melatonin contrast group). ANP was induced by the retrograde injection of 4% taurocholate (1 ml/kg body weight) into the biliopancreatic duct. Melatonin (50 mg/kg body weight) was administered 30 min before the induction of ANP in the melatonin treatment group. Rats in each group were euthanized at 1, 4, and 8 h after ANP induction. Pancreatic tissues were removed to measure SERCA and NCX levels and cytosolic calcium ion (Ca²⁺) concentration ([Ca²⁺]_i).ResultsAt each time point, SERCA and NCX levels in the melatonin treatment group were significantly higher than that in the ANP group, and lower than that in the sham group and the melatonin contrast group. These levels did not differ between the 4- and 8-h time points in the ANP group. [Ca²⁺]_i in pancreatic acinar cells was higher in the melatonin treatment group than in the sham group and the melatonin contrast group, but lower than in the ANP group, at each time point.ConclusionMelatonin can reduce pancreatic damage via the up-regulation of SERCA and NCX expression, which can alleviate calcium overload in pancreatic acinar cells.     

大黄对急性坏死性胰腺炎大鼠炎性介质表达的影响

目的 观察中药生大黄空肠灌注对急性坏死性胰腺炎(ANP)大鼠胰腺组织炎性介质表达的影响.方法 SD大鼠33只,按完全随机法分为对照组、ANP组及生大黄治疗组,每组11只.胰胆管逆行注射3％牛磺胆酸钠溶液方法制备ANP模型,同时做空肠造瘘.生大黄组于造模后空肠灌入1 g/ml生大黄煎液1ml/kg体重.造模36 h后处死大鼠.取血测定淀粉酶活性;取部分胰腺组织常规病理检查;取部分胰腺组织抽提总mRNA,采用实时PCR方法测定胰腺组织IL-6、IL-8、TNF-α mRNA表达.结果 造模后大鼠血淀粉酶活性明显升高,胰腺组织大片坏死、出血,大量炎细胞浸润,符合ANP改变.对照组胰腺组织IL-6、IL-8、TNF-αt mRNA表达量分别为0.29±0.13、0.35±0.15、1.09±0.32;ANP组分别为2.23 ±0.49、2.26±0.51、5.24±0.59,均较对照组显著增加(P值均＜0.05);生大黄组分别为0.97±0.30、1.02±0.34、2.59±0.36,均较ANP组显著减少,但仍显著高于对照组(P值均＜0.05).结论 生大黄空肠灌注治疗ANP大鼠可减少胰腺组织IL-6、IL-8、TNF-α mRNA的表达,从而减轻胰腺的病理损伤.     

Sensitivity of antiproteases, complement factors and C-reactive protein in detecting pancreatic necrosis. Results of a prospective clinical study

Summary Thirty-five patients with acute pancreatitis underwent serum monitoring of α-1-protease inhibitor, α-2-macroglobulin, complement factors C3+C4, and C-reactive protein (CRP). Edematous interstitial pancreatitis was shown to be present in 13 patients by contrast-enhanced computed tomography (CT) and laparotomy (n=3). Necrotizing pancreatitis was confirmed by laparotomy (n=21) and contrast-enhanced CT. There were significant differences between the serum values of all measured parameters in the two morphologically defined pancreatitis groups. The best discriminating factors were CRP and α-2-macroglobulin, showing 95% and 85% overall detection rates for pancreatic necrosis, respectively.     

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.     

褪黑素、维生素C在重症急性胰腺炎脂质过氧化反应中的作用

目的观察褪黑素(MLT)、维生素C(VitC)在实验性急性坏死性胰腺炎(ANP)时对脂质过氧化反应的影响。方法100只Wistar大鼠随机分为正常对照组(正常组)、ANP 生理盐水组(ANP组)、ANP MLT组(MLT组)、ANP VitC组(VitC组)、ANP MLT VitC组(联合组)。采用胰胆管末端穿刺逆行注入3%牛磺胆酸钠(1ml/kg体重)制备ANP模型。MLT组于制模后即刻皮下注射MLT50mg/kg体重,VitC组肌内注射VitC1g/kg体重。联合组则合并应用。术后6h和24h处死大鼠,取血检测血清淀粉酶(AMY)、血清丙二醛(MDA)和超氧化物歧化酶(SOD)活性。胰腺病变程度按病理学评分,电镜观察超微结构。结果MLT组、VitC组和联合组在各时间点的AMY及MDA含量较ANP组显著降低(P<0.01),各时间点的SOD活性较ANP组显著升高(P<0.01)。MLT组、VitC组和联合组各时间点的胰腺炎症、腺泡坏死程度及出血均较ANP组明显减轻,病理分值明显低于ANP组(P<0.01或P<0.05)。结论自由基所引发的脂质过氧化反应损伤是SAP发病过程中的重要因素之一,MLT及VitC可有效地减轻SAP时脂质过氧化反应损伤,明显减轻SAP时胰腺的病理改变,两者联合使用效果更佳。