Evidence for a role of free radicals by synthesized scavenger, 2-octadecylascorbic acid,in cerulein-induced mouse acute pancreatitis

To define the role of free radicals and of lipid peroxide involvement during the progress of cerulein-induced acute pancreatitis in mice, we evaluated the effect of a novel free radical scavenger, 2-octadecylascorbic acid (CV-3611), on pancreatic edema formation, and the levels of serum enzymes (amylase, lipase) and of lipid peroxide in pancreatic tissue. Mice were divided into three groups: control group, intraperitoneal injection of saline only; pancreatitis group, cerulein 50 g/kg injected intraperitoneally six times at 1-hr intervals; treatment group, CV-3611 10 mg/kg subcutaneously just after intraperitoneal cerulein injection. After the cerulein injection, the degree of pancreatic edema formation, serum amylase and lipase levels, and the amount of lipid peroxide in pancreatic tissue increased significantly during the observation period of 12 hr. Treatment with CV-3611 resulted in significant reduction in pancreatic edema formation at 3.5 hr (P<0.05) and 9 hr (P<0.05), serum amylase and lipase levels at 3.5 hr (P<0.05) and 12 hr (P<0.05), and lipid peroxide levels at 3.5 hr (P<0.05), 6 hr (P<0.05) and 12 hr (P<0.05). These results indicate that a novel free radical scavenger, CV-3611, has a strong therapeutic effect during the development of acute pancreatitis and suggest that oxygenderived free radicals play an important role in the pathogenesis of acute pancreatitis.     

Protective effects of endothelin-1 on acute pancreatitis in rats

Endothelin-1, a 21-residue peptide isolated from vascular endothelial cells, has a broad spectrum of actions. To clarify the involvement of endothelin-1 in acute pancreatitis, we examined the effects of endothelin-1 and its receptor antagonist BQ-123 on cerulein-induced pancreatitis in rats. Rats were infused intravenously with heparin-saline (control), endothelin-1 (100 pmol/kg/hr), cerulein (5 µg/kg/hr), or cerulein plus endothelin-1 for 3.5 hr. In another experiment, cerulein or cerulein plus BQ-123 (3 mg/kg/hr) was infused. Infusion of cerulein caused hyperamylasemia and pancreatic edema. Endothelin-1, when infused with cerulein, decreased the extent of pancreatic edema with a significant increase in the pancreatic dry- to wet-weight ratio. Histological changes induced by cerulein were markedly attenuated when endothelin-1 was given with cerulein. In contrast, endothelin-receptor blockade with BQ-123 further augmented pancreatic edema caused by cerulein. The extent of inflammatory cell infiltration was greater when BQ-123 was given with cerulein. Endothelin-1 or BQ-123 had no influence on hyperamylasemia. This study suggests that endothelin-1 has protective effects on experimental acute pancreatitis.Supported by a grant from the Ministry of Education, Japan (No. B-04454330).     

Oxidative stress: an important phenomenon with pathogenetic significance in the progression of acute pancreatitis

^a Division of Gastroenterology and Intensive Care Unit, Department of Medicine, Veterans General Hospital, Taipei, and School of Medicine, National Yang-Ming University, Taiwan, ^b Department of Biochemistry, College of Medicine, National Taiwan University, Taiwan

Correspondence to: Prof. F-J Lu, Department of Biochemistry, College of Medicine, National Taiwan University, No. 1, Jen-Ai Road, Taipei, Taiwan, Republic of China.

Accepted for publication 19 January 1998

Background—Reactive oxygen species and related oxidative damage have been implicated in the initiation of acute pancreatitis. Changes in these parameters during disease progression merit further investigation.
Aims—To evaluate changes and the clinical relevance of superoxide radicals, endogenous antioxidants, and lipid peroxidation during the course of acute pancreatitis.
Patients and methods—Superoxide radicals (measured as lucigenin amplified chemiluminescence), ascorbic acid, dehydroascorbic acid, α tocopherol, and lipid peroxidation (measured as thiobarbiturate reactive substances) were analysed in blood samples from 56 healthy subjects, 30 patients with mild acute pancreatitis, and 23 patients with severe acute pancreatitis. The association with grades of disease severity was analysed. Measurements were repeated one and two weeks after onset of pancreatitis.
Results—In the blood from patients with acute pancreatitis, there were increased levels of the superoxide radical as well as lipid peroxides. There was notable depletion of ascorbic acid and an increased fraction of dehydroascorbic acid. Changes in α tocopherol were not great except in one case with poor prognosis. Differences between severe and mild acute pancreatitis were significant (p<0.01). Variable but significant correlations with disease severity scores were found for most of these markers. The normalisation of these indexes postdated clinical recovery one or two weeks after onset of disease.
Conclusions—Heightened oxidative stress appears early in the course of acute pancreatitis and lasts longer than the clinical manifestations. The dependence of disease severity on the imbalance between oxidants and natural defences suggests that oxidative stress may have a pivotal role in the progression of pancreatitis and may provide a target for treatment.
(GUT 1998;:850-855)

Keywords: acute pancreatitis;  free radicals;  superoxides;  antioxidants;  lipid peroxidation

     

Protective effect of antithrombin III in acute experimental pancreatitis in rats

In the present study we investigated the therapeutic action of antithrombin III (AT III) in taurocholate-induced experimental pancreatitis with high lethality in rats. High-dose AT III treatment greatly improved the survival rate not only when given as pretreatment but also when given 2 hr after induction. No favorable effect on survival rate was observed on administration after 5 hr. Both intravascular and intraperitoneal AT III administration locally restored decreased AT III levels in the peritoneal cavity and increased plasma AT III to supranormal levels. The primary pancreatic insult seemed to be unaffected by the treatment, because neither the rise in plasma lipase nor the development of ascites or the extension of the pancreatic necrosis were diminished. Because heparin pretreatment of the rats was also effective, the mechanism of the beneficial action was probably mediated by inhibition of the proteases of the coagulation cascade, thereby preventing intravascular coagulation in the pancreas and distant organs and subsequent systemic complications. The high efficacy of AT III treatment in this experimental model may stimulate clinical studies evaluating the efficacy of AT III treatment in an early stage of acute pancreatitis.     

奥曲肽与丹参多酚酸盐合用对急性胰腺炎大鼠氧自由基影响的研究

[目的]探讨奥曲肽与丹参多酚酸盐合用对急性胰腺炎(AP)大鼠氧自由基的影响.[方法]SD大鼠75只,随机分为5组,每组15只.通过胰胆管逆行性注射牛磺胆酸钠制成AP大鼠模型.分别观察各实验组血清超氧化歧化酶(SOD)、丙二醛(MDA)的变化.[结果]①AP组与假手术组相比,血清SOD水平明显降低(P＜0.05),血清MDA水平明显升高(P＜0.05).②奥曲肽治疗组、丹参多酚酸盐治疗组及奥曲肽、丹参多酚酸盐合用组与AP组相比,血清SOD水平明显升高(P＜0.05),血清MDA水平明显降低(P＜0.05).③奥曲肽、丹参多酚酸盐合用组与奥曲肽、丹参多酚酸盐单用组相比,血清SOD水平明显升高(P＜0.05),血清MDA水平明显降低(P＜0.05).[结论]奥曲肽、丹参多酚酸盐通过升高SOD(保护性因素)、降低MDA(损伤性因素),对AP有明显治疗作用,且奥曲肽、丹参多酚酸盐合用效果更显著.     

Oxygen radical formation does not have an impact in the treatment of severe acute experimental pancreatitis using free cellular hemoglobin

AIM: Microcirculatory dysfunction and free oxygen radicals are important factors in the pathogenesis of severe acute pancreatitis. Additional oxygen delivery might enhance lipid peroxidation but may also improve pancreatic microcirculation. This study assesses the effect of free cellular bovine hemoglobin on the formation of oxygen radicals and microcirculation in a rodent model of severe acute pancreatitis. METHODS: Fifteen minutes after induction of acute pancreatitis Wistar rats received either 0.8 mL bovine hemoglobin (HBOC-200), hydroxyethyl starch (HES) or 2.4 mL of normal saline to ensure normovolemic substitution. After 6 h of examination the pancreas was excised and rapidly processed for indirect measurement of lipid peroxidation products malondialdehyde (MDA) and reduced glutathione (GSH) in pancreatic tissue. RESULTS: The single application of HBOC-200 improved pancreatic microcirculation and reduced histopathological tissue damage significantly. Tissue concentration of MDA did not differ between the groups. Also no differences in GSH levels were detected. CONCLUSION: Though the single application of HBOC-200 and HES improve pancreatic microcirculation, no differences in lipid peroxidation products were detected. The beneficial effect of additional oxygen supply (HBOC-200) does not lead to enhanced lipid peroxidation.     

Traditional Chinese medicine "Qing Yi Tang" alleviates oxygen free radical injury in acute necrotizing pancreatitis

AIM To observe the changes in oxygen free radical (OFR) and the curative effect of traditional Chinese medicine "Qing Yi Tang" in acute necrotizing pancreatitis (ANP).METHODS After induction of ANP by injection of sodium taurocholate into pancreatic duct, 16 dogs were randomly divided into control group and Chinese medicine group. Serum amylase, SOD and MDA were determined on postoperative day 1, 2, 4 and 7. The animals were sacrificed on day 7. SOD and MDA in organs were determined, and pathological changes in pancreas were observed.RESULTS As compared with control group, the serum level of amylase (734U/L vs 2783U/L) and MDA (7.8nmol/ml vs 14.8nmol/ml) in Chinese medicine group were decreased on day 7 (P＜0.05), while SOD increased significantly (281nU/ml vs 55nU/ml, P＜0.01), and similar changes occurred in MDA and SOD in organs, especially in the pancreas; the pathological changes in the pancreas were alleviated as well.CONCLUSION "Qing Yi Tang" is effective in clearing OFRs and alleviating pathological changes in ANP.     

An ultrastructural study to investigate the effect of allopurinol on cerulein-induced damage to pancreatic acinar cells in rat

Summary Conclusion Subcellular organelles and membranes were the structures most protected by allopurinol, indirectly demonstrating their role of main and early target of oxygen-derived free radicals in the pathogenesis of acute pancreatitis. Background The present work evaluates the ultrastructural changes during cerulein-induced acute pancreatitis in rat with and without treatment with allopurinol. Methods and Results Supramaximal doses of cerulein, injected intraperitoneally (50 μg/kg) twice, at 1-h interval, caused severe subcellular alterations, including zymogen distribution, pathological vacuoles, and damage to organelles and membranes. Cotreatment (40 mg/kg ip twice with 1-h interval;n=10 rats) and, most of all, pretreatment (40 mg/kg ip allopurinol, 1 h; 20 mg/kg ip allopurinol+50 μg/kg ip cerulein, 30 min; 40 mg/kg ip allopurinol, 30 min; 50 μg/kg ip cerulein;n=10 rats) with allopurinol showed significant morphological improvement.     

Protective effect of YHI and HHII against experimental acute pancreatitis in rabbits

AIM: To observe the protective effect of combined i.v. administraction of Yuanhu injection (YHI) and Huoxuehuayu injection-I (HHI-I) against acute pancreatitis (AP) in rabbits.METHODS: Sever acute pancreatitis (SAP) was induced by retrograde infusion of artificial bile juice into biliary-pancreatic duct, and treated with YHI and HHI-I intravenously. The protective effect was judged by the survival time and rate, serum amylase, serum interleukin-6, pancreatic microcirculation and pathological alteration.RESULTS: Combined use of YHI and HHI-I could markedly increase the rabbits’ 5-d survival rate after AP (83.3% in the treatment group and 33.3% in control). The serum amylase value (x^- ± s) decreased to 1596.6 U/L ± 760.50 U/L in the 5th day from the high level (6320.83 U/L ± 2614.12 U/L) in the 1st day after AP in the treatment group, while in the control group the amylase activity in the 5th day was 2095.0 U/L ± 1081.87 U/L, being significantly different from that before AP (837.17 U/L ± 189.12 U/L). YHI and HHI-I also obviously improved the pancreatic microcirculation and lowered the serum interleukin-6 level, one of the indices of severe pancreatitis. Pathological examination indicated all the changes typical for AP in YHI and HHI-I treatment group were milder than those in the control.CONCLUSION: YHI and HHI-I used in combination might have protective effect against acute pancreatitis in rabbits.     

Protective effect of YHI and HHI-I against experimental acute pancreatitis in rabbits

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超氧化物歧化酶对链脲佐菌素诱发糖尿病自由基代谢的影响

给链脲佐菌素诱导的糖尿病模型大鼠以超氧化物歧化酶（ＳＯＤ），观察其自由基代谢改变，结果表明，ＳＯＤ对改善糖尿病模型大鼠自由基代谢异常有作用。     

Effect of resveratrol on pancreatic oxygen free radicals in rats with severe acute pancreatitis

AIM:To investigate the therapeutic effects of resveratrol(RESV) as a free radical scavenger on experimental se-vere acute pancreatitis (SAP).METHODS:Seventy-two male Sprague-Dawley ratswere divided randomly into sham operation group,SAPgroup,and resveratrol-treated group.Pancreatitis wasinduced by intraductal administration of 0.1 mL/kg 4%sodium taurocholate.RESV was given intravenouslyat a dose of 20 mg/kg body weight.All animals werekilled at 3,6,12 h after induction of the model.Serumamylase,pancreatic superoxide dismutase (SOD),malondialdehyde (MDA),and myeloperoxidase (MPO)were determined.Pathologic changes of the pancreaswere observed under optical microscope.RESULTS:The serum amylase,pancreatic MPO andthe score of pathologic damage increased after theinduction of pancreatitis,early (3,6 h)SAP sampleswere characterized by decreased pancreatic SODand increased pancreatic MDA.Resveratrol exhibiteda protective effect against lipid peroxidation in cellmembrane caused by oxygen free radicals in theearly stage of SAP.This attenuation of the redox stateimpairment reduced cellular oxidative damage,asreflected by lower serum amylase,less severe pancreaticlesions,normal pancreatic MDA levels,as well asdiminished neutrophil infiltration in pancreas.CONCLUSION:RESV may exert its therapeutic effecton SAP by lowering pancreatic oxidative free radicals andreducing pancreatic tissue infiltration of neutrophils.     

丹参对重症急性胰腺炎早期多器官组织脂质过氧化的影响

[目的]研究丹参对重症急性胰腺炎(SAP)早期多器官组织脂质过氧化的影响及其作用机制.[方法]将30只大鼠随机分为3组,即正常组、模型组和丹参治疗组.采用逆行胰管注射法建立大鼠SAP模型,观察胰、心、肝、肺、肾组织的超氧化物歧化酶(SOD)、丙二醛(MDA)和组织学变化及丹参注射液对其的影响.[结果]模型组的多器官组织MDA增加、SOD活性降低,以胰、心、肝、肾为主;丹参注射液可升高胰、心、肝、肾等组织的SOD活性,降低胰、肝、肾组织的MDA水平.[结论]SAP早期存在着多器官组织脂质过氧化,相应组织中SOD活性的降低是其原因之一.丹参可提高SAP多器官组织SOD活性而减轻组织脂质过氧化,以胰、肝、肾为主.     

Effects of the superoxide radical scavenger superoxide dismutase,and of the hydroxyl radical scavenger mannitol,on reperfusion injury in isolated rabbit hearts

Summary Hydroxyl radical formation, secondary to superoxide radical generation, has been advocated as the actual mechanism of oxygen radical-mediated damage in biological systems. The present study was designed to compare the efficacy of administration of the hydroxyl radical scavenger mannitol vs. that of the superoxide radical scavenger superoxide dismutase (SOD) in reducing myocardial reperfusion injury, and to test whether combined treatment with both agents would confer better tissue protection compared with either intervention alone. Rabbit hearts perfused within a ³¹P nuclear magnetic resonance (³¹P-NMR) spectrometer were subjected to 30 minutes of total global ischemia at 37°C. At reflow, 12 hearts in each group received either (a) a bolus of standard perfusion buffer, followed by 45 minutes of reperfusion (controls); (b) the superoxide radical scavenger recombinant human SOD (h-SOD, as a 60,000 U bolus followed by a 100 U/ml infusion for 15 minutes); (c) the hydroxyl radical scavenger mannitol (50 mM bolus followed by 15 minutes of 50 mM infusion); or (d) a combination of both agents. All treated hearts were switched to standard buffer for the remaining 30 minutes of reperfusion. Treatment with h-SOD alone was associated with a significant improvement in the recovery of cardiac contractility and coronary flow, as well as of ATP content, compared to control hearts. In contrast, mannitol treatment resulted in a small, nonsignificant improvement in these parameters. The addition of mannitol to h-SOD did not result in further significant improvement of contractility and ATP recovery compared to h-SOD alone. These data demonstrate that under our experimental conditions significant protection against reperfusion injury can be achieved by the administration of h-SOD alone, without the need for additional hydroxyl radical scavenger therapy with mannitol. These results do not exclude that significant tissue protection may be achieved by different doses of mannitol or by other agents. However, they suggest that under definite experimental conditions prevention of hydroxyl radical formation, rather than attempts to minimize hydroxyl radical toxicity, might be a more efficient method to prevent oxygen radical-mediated reperfusion injury in isolated hearts.     

Protective effect of exogenous transferrin against hyperoxia: A study on premature rabbits

We hypothesized that an increase in plasma iron binding capacity would decrease the generation of oxygen radicals and of lipid peroxides. To test this hypothesis, we studied whether supplementation of transferrin (TF) in premature rabbits would modify the degree of hyperoxic lung injury. Animals, delivered prematurely at 29 days of gestation (term 31 days), were randomized and given either 0.5 g/kg of albumin (Alb) (n = 116) or 0.5 g/kg of iron-free TF (n = 132) intravenously within 2 hours after birth. Another group was randomized to receive saline (n = 15), or either 0.35 g/kg (n = 12) or 0.70 g/kg of iron-free TF (n = 8). After exposure to a 100% oxygen environment for 2 or 4 days, the animals were killed, and plasma and bronchoalveolar lavage (BAL) fluid was recovered. Infusion of TF caused a dose-dependent increase in the concentration of TF and an increase in the unsaturated iron-binding capacity. Administration of TF at birth increased the gradient of TF between serum and alveolar epithelial lining fluid on day 4, suggesting decreased alveolar-capillary permeability. BAL fluid and plasma from TF-supplemented animals contained less lipid peroxidation products and more inhibitor of lipid peroxidation than BAL fluid or plasma from Alb-treated animals. In TF-treated animals, the recovery of protein in BAL fluid (TF group, 1.26 ± 0.07 mg; Alb group, 1.78 ± 0.10 mg; P = 0.02) and the water content of the extravascular lung tissue (TF group, 78.5 ± 1.4%; Alb group, 83.2 ± 1.3%; P = 0.05) were lower than in Alb-treated animals. We propose that supplementation of iron-free TF decreases iron-catalyzed redox reactions and may decrease hyperoxic lung injury in the premature. Pediatr. Pulmonol. 1997; 24:429–437. © 1997 Wiley-Liss, Inc.     

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...     

Evidence for a role of mitogen-activated protein kinases in the treatment of experimental acute pancreatitis

Acute pancreatitis(AP) is an inflammatory disease characterized by acute inflammation and necrosis of the pancreatic parenchyma. AP is often associated with organ failure, sepsis, and high mortality. The pathogenesis of AP is still not well understood. In recent years several papers have highlighted the cellular and molecular events of acute pancreatitis. Pancreatitis is initiated by activation of digestive enzymes within the acinar cells that are involved in autodigestion of the gland, followed by a massive infiltration of neutrophils and macrophages and release of inflammatory mediators, responsible for the local and systemic inflammatory response. The hallmark of AP is parenchymal cell necrosis that represents the cause of the high morbidity and mortality, so that new potential therapeutic approaches are indispensable for the treatment of patients at high risk of complications. However, not all factors that determine the onset and course of the disease have been explained. Aim of this article is to review the role of mitogen-activated protein kinases in pathogenesis of acute pancreatitis.     

清下化瘀方对急性胰腺炎胃肠道及免疫功能的保护作用

[目的]：评价清下化瘀方配合常规西药治疗对急性胰腺炎的胃肠道及免疫功能的保护作用.[方法]将65例急性胰腺炎患者分为治疗组32例、对照组33例.其中,对照组给予西药常规治疗,治疗组在西药常规治疗的基础上加服清下化瘀方.2组均治疗7d后,通过观察临床症状积分的缓解程度以及监测血淀粉酶、CRP、补体C3/C4,并给予APACHEⅡ积分评分评价其功能.[结果]治疗后2组患者的中医症状积分较治疗前均有明显下降,2组治疗前后胃肠道症状比较差异有统计学意义（P＜0.05或P＜0.01）.2组比较,血清CRP、血清补体C3、血淀粉酶差异均有统计学意义：治疗前2组血淀粉酶（AMY）明显高于正常值,治疗后2组AMY明显下降,治疗组恢复至正常值.2组治疗后血淀粉酶差值比较有统计学意义;治疗后2组CRP比较差异有统计学意义（P＜0.01）;2组治疗前C3、C4均有所上升,且2组比较差异无统计学意义;治疗后C3、C4恢复至正常水平,其中2组C3比较差异有统计学意义（P＜0.05）.2组治疗前评分值均接近重症急性胰腺炎的评分标准（APACHEⅡ评分≥8分）,经治疗后2组均有明显下降.[结论]清下化瘀方结合西药常规治疗急性胰腺炎,对其胃肠道及免疫功能有良好的保护作用.     

生长抑素联合生长激素治疗对重症急性胰腺炎大鼠脑损伤的保护作用

目的 观察重症急性胰腺炎(SAP)时脑损伤与血清内皮素(ET)-l／一氧化氮(NO)比值的关系以及生长抑素和生长激素的保护作用。方法 80只大鼠经胰胆管逆行注射3．5％牛磺胆酸钠2．5n11／kg建立SAP模型，然后分成4组：重症胰腺炎组(SAP组)，生长抑素组(S组，每天静脉注射42μg／1kg，共2d)，生长激素组(G组，每天皮下注射O．5μg／kg，共2d)和联合治疗组，每组20只。另取20只不造模大鼠为正常对照组。观察各组治疗前后脑水肿、血脯屏障、脑细胞凋亡变化以及与血清ET-1／N0的相关性,结果SAP大鼠血清ET-1／NO显著升高，与脑水肿、血脑屏障损伤程度及脑细胞凋亡呈正相关。生长激素和生长抑素可降低血清ET-1／N0水平，减轻脑组织水肿，减少脑细胞凋亡，改善血脑屏障通透性。同时观察到SAP大鼠脑电图呈慢波改变，治疗后好转。结论生长激素和生长抑素可降低SAP大鼠血清ET-1／NO比值，改善脑水肿和血脑屏障通透性，减少脑细胞凋亡，对SAP时的脑损伤有保护作用。