N-乙酰半胱氨酸预防重症急性胰腺炎的实验研究

背景：还原型谷胱甘肽（GSH）是细胞内最重要的非酶类抗氧化剂,各种急性胰腺炎（AP）动物模型均存在腺泡细胞GSH耗竭。目的：探讨N-乙酰半胱氨酸（NAC）对重症急性胰腺炎（SAP）的预防作用及其可能机制。方法：54只健康雄性Wistar大鼠随机分为3组,正常对照组予假手术,AP模型组和NAC预处理组胰胆管逆行注射牛磺胆酸钠以模拟人类SAP,NAC预处理组于造模前30min腹腔注射NAC。分别于术后3h、6h、12h检测血清Ca^2＋、丙二醛（MDA）和胰腺组织GSH,透射电子显微镜（TEM）观察胰腺组织超微结构。结果：术后3h、6h至12h,各组血清Ca^＋浓度、胰腺组织GSH含量逐渐降低,血清MDA水平逐渐升高。NAC预处理组各时点血清Ca^2＋浓度、胰腺组织GSH含量均显著高于AP模型组（P〈0．05）,血清MDA水平显著低于AP模型组（P〈0．05）。TEM观察显示AP模型组腺泡细胞胞质内可见大量空泡,酶原颗粒分泌、排出明显减少;NAC预处理组空泡体积较小,酶原颗粒排出增加。结论：NAC可在SAP早期恢复腺泡细胞的GSH含量,通过抗氧化作用减轻腺泡细胞的氧化损伤,维持细胞内钙平衡,改善酶原颗粒的转运和排泌,从而对SAP的发展产生预防作用。     

N-乙酰半胱氨酸对重症急性胰腺炎大鼠肝损伤的保护作用

目的:探讨N-乙酰半胱氨酸(N-acetylcysteine,NAC)对重症急性胰腺炎(severe acute pan-creatitis,SAP)大鼠肝损伤的保护作用及作用机制.方法:Wistar大鼠42只随机分为3组,SAP组(SAP,n=18),采用逆行十二指肠胰胆管注射50 g/L牛黄胆酸钠溶液制备SAP模型;SAP+NAC组(SAP+NAC,n=18),建模前2 h给予NAC 300 mg/kg体质量预处理;假手术组(SO,n=6).建模成功后3、6和12 h,分别取下腔静脉血液、胰腺和肝脏组织.光镜下观察胰腺和肝脏组织病理改变,全自动生化分析仪检测各时段血液ALT和AST水平,逆转录-聚合酶链反应(RT-PCR)检测肝脏组织中TNF-αmRNA表达,SP免疫组化法检测肝脏组织中NF-κB活化.结果:SO组血液ALT、AST以及肝胰组织病理无显著性变化.SAP组各时间点肝胰病理改变较SO组严重.术后3、6和12 h时间点ALT及AST均较SO组显著升高(186.67±27.28,321.17±56.14,492.50±69.77 vs 36.83±7.02;255.50±44.15,343.17±43.70,425.33±58.37 vs 41.67±5.35,P<0.05或0.01);TNF-αmRNA表达均显著高于SO组(0.37±0.03,0.77±0.04,0.54±0.04 vs 0.24±0.03,P<0.05或0.01):NF-κB活性术后3、6 h均显著高于SO组(51.95±4.76.24.67±4.93 vs 9.33±2.05,P<0.05或0.01),12 h与SO组相比差异无显著性意义.SAP+NAC组各时间点肝胰组织病理改变均较SAP组减轻,术后3-12 h血液ALT及AST水平(143.67±16.62,203.33±25.41,301.17±26.82;136.33±26.27,221.50±38.31,310.50±38.17)均显著低于SAP组(P<0.05或0.01);各时间点肝脏TNF-αmRNA表达(0.25±0.03,0.50±0.05,0.43±0.03)显著低于SAP组(P<0.05或0.01);术后3-6 h NF-κB活性(37.60±6.37,12.88±2.66)均较SAP组显著降低(P<0.05).结论:NF-κB活化与TNF-αmRNA表达上调参与了SAP大鼠肝损伤过程,NAC 300 mg/kg预处理能够有效减轻SAP大鼠肝损伤,其作用机制可能与抑制NF-κB活化进而下调炎性细胞因子TNF-αmRNA表达水平相关.     

N-乙酰半胱氨酸对大鼠重症急性胰腺炎肝损伤的抑制作用

目的:探讨N-乙酰半胱氨酸(N-acetylcysteine,NAC)对大鼠重症急性胰腺炎(SAP)肝损伤的抑制作用机制.方法:54只SD大鼠随机分为假手术组(SO组)、胰腺炎组(SAP组)及NAC干预组(NAC组).各组18只.以4%牛磺胆酸钠溶液逆行注入胰胆管制作SAP模型.NAC组于造模后1 h行股静脉注入NAC(200 mg/kg).分别于3 h、6h、12 h时间点随机剖杀大鼠.采用SP免疫组织化学法检测肝组织NF-κB活性;利用逆转录-聚合酶链反应(RT-PCR)法检测肝组织iNOSmRNA表达;胰、肝组织行病理切片观察,同时行血清淀粉酶、肝功能(AST、ALT)检测.结果:SO组肝组织可见散在肝细胞NF-κB活化和iNOS mRNA低表达,SAP组NF-κB活化和iNOS mRNA高表达:NAC对肝组织NF-κB活性有抑制作用,降低iNOS mRNA表达,与SAP组比较差异显著(3 h:0.32±0.05 vs 0.46±0.04.6 h:0.56±0.07 vs 0.97±0.18,12 h:0.87±0.14 vs 1.13±0.11,均P<0.05),并可降低血清淀粉酶、AST、ALT水平.结论:肝组织NF-κB活化及iNOS mRNA过度表达可能是SAP肝损伤发生的原因之一,NAC可抑制肝NF-κB活性及iNOS mRNA的表达,对SAP肝损伤具有一定的抑制作用.     

抗氧化剂对急性坏死性胰腺炎大鼠一氧化氮、丙二醛的影响

目的　探讨抗氧化剂N_乙酰半胱氨酸 (NAC)对急性坏死性胰腺炎 (ANP)大鼠胰腺组织一氧化氮 (NO)及丙二醛(MDA)的影响。方法　雄性SD大鼠 114只 ,随机分成正常对照组 (C组 ,n =3 0 )、急性胰腺炎组 (A组 ,n =42 )和NAC干预组 (N组 ,n= 42 )。A组分 2次腹腔内注射 8%L_精氨酸 (L_Arg) 1 2mg/g诱导ANP ;C组同法腹腔内注射等量生理盐水 ;N组先提前 1小时 (h)腹腔内注射 0 5mol/L的NAC 0 0 5mg/g ,然后同A组方法诱导ANP。在首次注射L_Arg后于 6h、12h、2 4h、3 6h、48h、72h分批处死大鼠 ,观察大鼠胰腺组织NO和MDA水平及胰腺病理变化。结果　N组各时点NO和MDA水平均较A组明显降低 (均P <0 0 1或P<0 0 5) ,N组 12h、2 4h、3 6h、48h、72h的胰腺病理改变较A组的明显减轻 (均P <0 0 1或P <0 0 5)。结论　NAC可降低胰腺组织NO、MAD水平 ,减轻了实验性ANP大鼠的胰腺损害 ,对胰腺组织有保护作用     

N-乙酰半胱氨酸对肝脏保护作用的研究进展

<正>N-乙酰半胱氨酸(NAC)最早在治疗扑热息病中毒时就已经显示出其对肝脏具有保护作用。近年来,随着研究的不断深入,人们发现NAC对多种肝脏疾病均具有一定的改善作用。其作为细胞内还原性谷胱甘肽(GSH)的前体,具有抗氧化、抗凋亡、抑制炎性介质释放、调节细胞代谢等作用^[1,2]。根据这个独特作用优势,NAC在肝脏相关疾病的治疗中越来越受到关注。本文通过查阅文献,将NAC治疗多种肝病的保护作用进行收集整理,现综述如下。     

N-乙酰半胱氨酸在肝病治疗中的应用

N—乙酰半胱氨酸(N—acetylcysteine，NAC)是细胞内还原性谷胱甘肽的前体。主要作为一种粘液溶解剂应用于临床上冶疗呼吸系统疾病，迄今已30多年。NAC除具有粘液溶剂作用外，在还原性谷胱甘肽降低和氧化应激时以及帕金森氏病等方面也被研究和利用。由于NAC对肝脏的保护作用，其静脉和口服制剂广泛用于醋氨酚(对乙酰氨基酚)中毒所致的肝脏损害。     

依达拉奉对大鼠重症急性胰腺炎的保护作用

目的:探讨依达拉奉对L-精氨酸诱导的重症急性胰腺炎(SAP)大鼠的治疗作用及机制.方法:将60只大鼠随机分为三组( n = 20). 采用大鼠腹腔内分次注射大剂量L-精氨酸(2.5g/k g×2, 间隔1 h)的方法制备SAP大鼠模型, 治疗组大鼠腹腔内注射依达拉奉注射液3 mg/kg, bid×3 d. 72 h后比较三组大鼠胰腺组织病理变化、腹水性状及量、血清淀粉酶(AMY)、TNF-α、IL-6水平和胰腺组织丙二醛(MDA)、超氧化物歧化酶(SOD)、还原型谷胱甘肽(GSH)含量及预后.结果:72 h后, 与对照组相比, SAP组出现典型的SAP病理形态改变, 腹水量较多(5.16±1.52vs 0.50±0.10, P<0.01), 且大鼠血清AMY、TNF-α、I L-6及胰腺组织M DA均显著升高(8967.5±298.4 vs 720.1±119.7; 103.98±10.56 vs 41.59±3.79; 548.57±10.45 vs 198.34±2.10; 35.6±3.8 vs 7.9±2.2, 均P<0.01), 胰腺组织抗氧化物质GSH、SOD明显降低(7.2±0.6 vs 17.1±2.1; 7300±1800 vs 28400±2700,均P<0.01); 与SAP组相比, 治疗组胰腺组织病理损害减轻, 腹水量减少(4.05±1.22 vs 5.16±1.52, P<0.05), 且组织病理评分较低( P<0.05),血清AMY、TNF-α、IL-6及胰腺组织MDA明显降低(7809.5±158.3 vs 8967.5±298.4; 79.80±14.23 vs 103.98±10.56; 467±6.64 vs 548.57±10.45; 29.1±2.6 vs 35.6±3.8, 均P<0.05), 胰腺组织GSH、SOD升高(8.7±1.3 vs 7.2±0.6;114 000±27 000 vs 7300±1800, 均P<0.05).结论:依达拉奉能清除氧自由基、提高胰腺组织抗氧化物质SOD和GSH含量, 降低促炎细胞因子水平, 可减轻胰腺组织的病理损害,并且有可能降低死亡率.     

N-乙酰半胱氨酸在减轻大鼠重症急性胰腺炎肠损伤中的作用

目的:观察N-乙酰半胱氨酸(N-acetylcysteine,N A C)对重症急性胰腺炎(severe acute pancreatitis,SAP)大鼠血浆肿瘤坏死因子(tumor necrosis factor α,TNF-α)、白细胞介素1(interleukin-1β,IL-1β)、IL-10及小肠组织细胞间黏附分子1(intercellular cell adhesionmolecule-1,ICAM1)表达的影响,并探讨其对大鼠SAP相关肠损伤保护作用的机制.方法:72只Wistar大鼠随机分为假手术组(SO组)、SAP组及NAC干预组(NAC组).每组再分为6、12、24 h共3个时相点,每个时相点各8只大鼠.通过胰胆管逆行注射5%牛磺胆酸钠制作大鼠SAP模型,SO组用同样方法经胰胆管逆行注射生理盐水,NAC组大鼠在制作SAP模型前1 h经腹腔注射NAC,SO组及SAP组在术前1 h经腹腔注射同NAC等体积的生理盐水.动物分别于术后6、12、24 h麻醉后取材,检测血浆淀粉酶(plasma amylase,AMY)、内毒素、D-乳酸,二胺氧化酶(diamine oxidase,DAO)、TNF-α、IL-1β及IL-10含量,观察小肠组织病理学变化并进行评分,实时荧光定量PCR(Real-time PCR)检测小肠组织ICAM1mRNA的表达,Western blot法检测小肠组织ICAM1蛋白变化.结果:NAC组各时相点大鼠AMY、TNF-α及IL-β水平均较SAP组各对应时相点降低,IL-10水平则明显增高,内毒素、DAO和D-乳酸在12和24 h时也明显降低;SO组大鼠小肠组织无明显病理学改变,NAC组大鼠小肠病理改变较SAP组明显改善,小肠组织病理学评分在12及24 h亦明显降低.NAC组大鼠小肠组织中ICAM1 mRNA(6 h:1.13±0.28 vs 2.37±0.63;12 h:1.27±0.34 vs 2.94±0.82;24 h:1.19±0.26 vs 2.68±0.95,均P<0.05)及蛋白(6 h:0.74±0.11 vs 1.04±0.25;12 h:0.88±0.17 vs1.25±0.33;24 h:0.75±0.13 vs 1.18±0.22,均P<0.05)的表达与SAP组相应时相点比较均明显减弱.结论:NAC可以减轻SAP大鼠肠损伤,其机制除其可以抑制TNF-α、IL-1β并促进IL-10的释放外,还可能与其对小肠组织ICAM1表达的调节作用有关.     

N-乙酰半胱氨酸对大鼠肺缺血再灌注损伤的保护作用

目的探讨N-乙酰半胱氨酸(NAC)对大鼠在体肺缺血再灌注(I/R)损伤的保护作用。方法建立大鼠在体肺缺血再灌注模型,将30只SD大鼠随机分成假手术对照组,缺血再灌注组(I/R组)和N-乙酰半胱氨酸组(NAC组),NAC组缺血前1 h给予腹腔注射N-乙酰半胱氨酸200 mg/kg。再灌注2 h后摘取左肺,分别对各组进行以下检测:肺湿/干比(W/D)、超氧化物歧化酶(SOD)活力、髓过氧化物酶(MPO)活性、丙二醛(MDA)含量并进行病理学检查及肺组织损伤定量评价(IQA)。结果I/R组肺W/D和IQA显著高于假手术组(P0.01),NAC组上述指标明显降低(P0.01)。病理学结果显示三组动物肺组织结构基本正常,假手术组无充血;与NAC组比较,I/R组肺组织充血明显、白细胞浸润更严重及肺间质高度淤血水肿。I/R组MDA含量和MPO活性较假手术组明显升高(P0.01),SOD活性显著下降(P0.01)。NAC能明显减少MDA含量和降低MPO活性,提高SOD活性(P0.01)。结论N-乙酰半胱氨酸对肺缺血再灌注损伤具有保护作用,可能与其抗氧化作用和抑制中性粒细胞激活有关。     

N-乙酰半胱氨酸干预治疗重症急性胰腺炎肺损伤的实验研究

急性肺损伤（acute lung injury,ALI）是重症急性胰腺炎（SAP）的常见并发症,患者常因合并急性呼吸窘迫综合征导致呼吸衰竭而死亡.本实验通过建立大鼠SAP模型,并给予N乙酰半胱氨酸（N-acetylcysteine,NAC）预处理,探讨NAC对重症急性胰腺炎肺损伤的干预治疗作用及其作用机制.     

鱼油对重症急性胰腺炎大鼠肠黏膜屏障的影响

目的:探讨 -3鱼油脂肪乳剂对重症急性胰腺炎(SAP)大鼠早期肠黏膜功能屏障的影响.方法:♂Wistar大鼠30只随机分为:假手术组(So组,n=10),鱼油治疗组(F组,n=10)和生理盐水治疗组(N组,n=10).通过胰管逆行注射法建成SAP模型,并分别尾静脉注射 -3鱼油脂肪乳剂和生理盐水治疗.检测大鼠血浆D-乳...     

Pioglitazone attenuates the severity of sodium taurocholate-induced severe acute pancreatitis

AIM： To determine the effect of pioglitazone, a specific peroxisome proliferator-activated receptor-γ, （PPARγ） ligand, on development of severe acute pancreatitis （SAP） and expression of nuclear factor-kappa B （NF-κB） and intercellular adhesion molecule-1 （ICAM-1） in the pancreas. METHODS： Male Sprague-Dawley （SD） rats （160-200 g） were randomly allocated into three groups （n = 18 in each group）： severe acute pancreatitis group, pioglitazone group, sham group. SAP was induced by retrograde infusion of 1 mL/kg body weight 5% sodium taurocholate （STC） into the biliopancreatic duct of male SD rats. Pioglitazone was injected intraperitoneally two hours piror to STC infusion. Blood and ascites were obtained for detecting amylase and ascitic capacity. Pancreatic wet/dry weight ratio, expression of NF-κB and ICAM-1 in pancreatic tissues were detected by immunohistochemical staining. Pancreatic tissue samples were stained with hematoxylin and eosin （HE） for routine optic microscopy. RESULTS： Sham group displayed normal pancreatic structure. SAP group showed diffuse hemorrhage, necrosis and severe edema in focal areas of pancreas. There was obvious adipo-saponification in abdominal cavity. Characteristics such as pancreatic hemorrhage, necrosis, severe edema and adipo-saponification were found in pioglitazone group, but the levels of those injuries were lower in pioglitazone group than those in SAP group. The wet/dry pancreatic weight ratio, ascetic capacity, serum and ascitic activities of anylase in the SAP group were significantly higher than those in the sham group and pioglitazone group respectively （6969.50 ± 1368.99 vs 2104.67 ± 377.16, 3.99 ± 1.22 vs 2.48 ± 0.74, P 〈 0.01 or P 〈 0.05）. According to Kusske criteria, the pancreatic histologic score showed that interstitial edema, inflammatory infiltration, parenchyma necrosis and parenchyma hommorrhage in SAP group significantly differed from those in the sham group and pioglitazone group （7.17 ± 1.83 vs     

Hepatic effect of NAC on sevear acute pancteatise of rats

Objective:To analyze the hepatic protection of n-acetvl cysteine(NAC)on severe acute pancreatitis(SAP).Methods:SD rats were randomly divided into control group,SAP group and NAC group.SAP AHO method was adopted to establish the model,2 h after modeling,rats in NAC group had intraperitoneal injection of NAC(200 mg/kg).Ten rals from each group were sacrifieed in even'6 and 12 h at different time[mints respectively.Liver damage,liver function and serum amylase,AST,ALT and malondialdehyde(MDA)were determined.Results:Serum amylase,AST,AIT and MDA content in SAP,NAC group at each time point were significantly higher in the control group(P0.05),serum amylase,AST,ALT and MDA content in NAC group rats were lower in the SAP group significantly(P0.05);Microscopic examination showed that the liver injury in rats and the NAC group significantly reduced in the SAP group.Conclusions:NAC provides effective protection against liver damage to SAP,protective from SAP liver injury.     

Protective effects of rhubarb on experimental severe acute pancreatitis

AIM: To investigate the effects of rhubarb on severe acute pancreatitis (SAP) in rats. METHODS: Severe acute pancreatitis was induced by two intraperitoneal injections of cerulein (40 μg/kg body weight) plus 5-h restraint water-immersion stress. Rhubarb (75-150 mg/kg) was orally fed before the first cerulein injection. The degree of pancreatic edema, serum amylase level, local pancreatic blood flow (PBF), and histological alterations were investigated. The effects of rhubarb on pancreatic exocrine secretion in this model were evaluated by comparing with those of somatostatin. RESULTS: In the Cerulein+Stress group, severe edema and diffuse hemorrhage in the pancreas were observed, the pancreatic wet weight (11.60&#177;0.61 g/Kg) and serum amylase (458 490&#177;43 100 U/L) were markedly increased (P&lt;0.01 vs control). In the rhubarb (150 mg/kg) treated rats, necrosis and polymorphonuclear neutrophil (PMN) infiltration in the pancreas were significantly reduced (P&lt;0.01), and a marked decrease (50%) in serum amylase levels was also observed (P&lt;0.01). PBF dropped to 38% (93&#177;5 mL/min per 100 g) of the control in the Cerulein+Stress group and partly recovered in the Cerulein+Stress+Rhubarb 150 mg group (135&#177;12 mL/min per 100 g) (P&lt;0.01). The pancreatic exocrine function was impaired in the SAP rats. The amylase levels of pancreatic juice were reduced in the rats treated with rhubarb or somatostatin, comparing with that of untreated SAP group. The bicarbonate concentration of pancreatic juice was markedly elevated only in the rhubarbtreated group (P&lt;0.01). CONCLUSION: Rhubarb can exert protective effects on SAP, probably by inhibiting the inflammation of pancreas, improving pancreatic microcirculation, and altering exocrine secretion.     

Ultrastructural clues for the protective effect of ascorbic acid and N-acetylcysteine against oxidative damage on caerulein-induced pancreatitis.

BACKGROUND: Oxygen free radicals (OFR) have been implicated in the induction of acute pancreatitis (AP). AIMS: The aim of this study was to determine the effect of ascorbic acid and N-acetylcysteine (NAC), potent antioxidants, against oxidative stress in AP. METHODS: AP was induced by two i.p. injections of caerulein at 2-hour intervals (50 microg/kg BW). One group received additionally an antioxidant mixture composed of L(+)-ascorbic acid (14.3 mg/kg BW) and NAC (181 mg/kg BW) i.p. The rats were sacrificed 12 h after the last injection. Oxidative stress markers were evaluated. Light-microscopic and ultrastructural examination was performed. RESULTS: Formation of vacuoles, mitochondrial damage, and dilatation of rough endoplasmic reticulum, margination and clumping of chromatin were major ultrastructural alterations in AP group. Ascorbic acid + NAC prevented these changes. Small vacuoles were present within the cytoplasm of some of the acinar cells. Pancreas damage was accompanied by an increase in tissue malondialdehyde (MDA) levels (p < 0.05), whereas a decrease was seen in catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) activities and total glutathione (GSH) levels (p < 0.005). Ascorbic acid + NAC decreased MDA levels but increased CAT, SOD, GPx activities and GSH levels (p < 0.005). CONCLUSION: These results suggest that ascorbic acid + NAC is potentially capable of limiting pancreatic damage produced during AP via protecting fine structure of acinar cells and tissue antioxidant enzyme activities.     

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.     

Emodin alleviates intestinal mucosal injury in rats with severe acute pancreatitis via the caspase-1 inhibition

BACKGROUND:Emodin,a traditional Chinese medicine,has a therapeutic effect on severe acute pancreatitis(SAP),whereas the underlying mechanism is still unclear.Studies showed that the intestinal mucosa impairment,and subsequent release of endotoxin and proinflammatory cytokines such as IL-1β,which further leads to the dysfunction of multiple organs,is the potentially lethal mechanism of SAP.Caspase-1,an IL-1β-converting enzyme,plays an important role in this cytokine cascade process.Investigation of the effect of emodin on regulating the caspase-1 expression and the release proinflammatory cytokines will help to reveal mechanism of emodin in treating SAP.METHODS:Eighty Sprague-Dawley rats were randomly divided into four groups(n=20 each group):SAP,sham-operated(SO),emodin-treated(EM) and caspase-1 inhibitor-treated(ICE-I) groups.SAP was induced by retrograde infusion of 3.5% sodium taurocholate into the pancreatic duct.Emodin and caspase-1 inhibitor were given 30 minutes before and 12 hours after SAP induction.Serum levels of IL-1β,IL-18 and endotoxin,histopathological alteration of pancreas tissues,intestinal mucosa,and the intestinal caspase-1 m RNA and protein expressions were assessed 24 hours after SAP induction.RESULTS:Rats in the SAP group had higher serum levels of IL-1β and IL-18(P0.05),pancreatic and gut pathological scores(P0.05),and caspase-1 m RNA and protein expressions(P0.05) compared with the SO group.Compared with the SAP group,rats in the EM and ICE-I groups had lower IL-1β and IL-18 levels(P0.05),lower pancreatic and gut pathological scores(P0.05),and decreased expression of intestine caspase-1 m RNA(P0.05).Ultrastructural analysis by transmission electron microscopy found that rats in the SAP group had vaguer epithelial junctions,more disappeared intercellular joints,and more damaged intracellular organelles compared with those in the SO group or the EM and ICE-I groups.CONCLUSIONS:Emodin alleviated pancreatic and intestinal mucosa injury in experimental SAP.Its mechanism may partly be mediated by the inhibition of caspase-1 and its downstream inflammatory cytokines,including IL-1β and IL-18.Our animal data may be applicable in clinical practice.     

Major pathological mechanisms of acute pancreatitis are prevented by N-acetylcysteine

AIM: To analyze the capability of N-acetylcysteine (NAC) to prevent major intra-acinar pathogenic mechanisms involved in the development of acute pancreatitis (AP). METHODS: AP was induced by pancreatic duct obstruction (PDO) in rats. Some animals received NAC (50 mg/kg) 1 h before and 1 h after PDO. During a 24-hour period of PDO, plasma amylase activity and pancreatic glutathione and malondialdehyde levels were measured. Cytosolic Ca(2+) levels and enzyme (amylase and trypsinogen) load in acinar cells were also analyzed by flow cytometry, and histological analysis of the pancreas was performed by electron microscopy. RESULTS: NAC avoided glutathione depletion at early AP stages, thereby preventing pancreatic oxidative damage, as reflected by normal malondialdehyde levels. By limiting oxidative stress, NAC treatment effectively prevented the impairment of Ca(2+) homeostasis found in acinar cells from early AP onwards, thus protecting the pancreas from damage. In addition, lower quantities of digestive enzymes were accumulated within acinar cells. This finding, together with the significantly lower hyperamylasemia observed in these animals, suggests that NAC treatment palliates the exocytosis blockade induced by PDO. CONCLUSION: By preventing oxidative stress at early AP stages, NAC administration prevents other pathological mechanisms of AP from being developed inside acinar cells, thus palliating the severity of disease.