Long-term aspirin pretreatment in the prevention of cerulein-induced acute pancreatitis in rats

AIM:To investigate the effects of long term pretreatment with low-,medium-and high-dose aspirin(acetylsalicylic acid,ASA) on a model of acute pancreatitis(AP) induced in rats.METHODS:Forty male Wistar rats were used.Three experimental groups,each consisting of eight animals,received low-(5 mg/kg per day),medium-(150 mg/kg per day) and high-dose(350 mg/kg per day) ASA in supplemented pellet chow for 100 d.Eight animals,serving as the AP-control group,and another eight,serving as reference value(RV) group,were fed with standard pellet chow for the same period.After pretreatment,AP was induced in the experimental animals by intraperitoneal administration of cerulein(2 × 50 μg/kg),while the RV group received saline in the same way.Twelve hours after the second injection,the animals were sacrificed.Pancreatic tissue and plasma samples were collected.One part of the collected pancreatic tissues was used for histopathological evaluation,and the remaining portion was homogenized.Cytokine levels [tumor necrosis factor,interleukin(IL)1β,IL-6],hemogram parameters,biochemical parameters(amylase and lipase),nuclear factor-κB,aspirin triggered lipoxins and parameters related to the antioxidant system(malondialdehyde,nitric oxide,hemeoxygenase-1,catalase and superoxide dismutase) were measured.RESULTS:Cerulein administration induced mild pancreatitis,characterized by interstitial edema(total histopathological score of 5.88 ± 0.44vs 0.25 ± 0.16,P < 0.001).Subsequent pancreatic tissue damage resulted in an increase in amylase(2829.71 ± 772.48 vs 984.57 ± 49.22 U/L,P = 0.001) and lipase(110.14 ± 75.84 U/L vs 4.71 ± 0.78 U/L,P < 0.001) in plasma,and leucocytes(6.89 ± 0.48 vs 4.36 ± 0.23,P = 0.001) in peripheral blood.Cytokines,IL-1β(18.81 ± 2.55 pg/μg vs 6.65 ± 0.24 pg/μg,P = 0.002) and IL-6(14.62 ± 1.98 pg/μg vs 9.09 ± 1.36 pg/μg,P = 0.04) in pancreatic tissue also increased.Aspirin pretreatment reduced the increase in the aforementioned parameters to a certain degree and partially improved the histopathological alterations caused by cerulein.No evidence of side effects related to chronic ASA administration(e.g.,inflammation or bleeding) was observed in the gastrointestinal tract in macroscopic and histopathological examination.CONCLUSION:Long term ASA pretreatment could prevent and/or ameliorate certain hematological,serological and histological alterations caused by ceruleininduced AP.

Effects of melatonin on the oxidative damage and pancreatic antioxidant defenses in ceruleininduced acute pancreatitis in rats

BACKGROUND： Oxidative stress is recognized as a pivotal effector of several pathogenic processes, including acute pancreatitis. Reactive oxygen species not just cause damage on the main cellular components, but also influence the expression of antioxidant system genes. Antioxidant molecules, such as melatonin, could be good candidates for the treatment of this multidimensional disease. The present study was to evaluate the chemopreventive effect of melatonin in a rat model of ceruleininduced acute pancreatitis.METHODS： Four subcutaneous injections of cerulein（20 μg/kg body weight） were given to Wistar rats at two hours intervals;melatonin was injected intraperitoneally（25 mg/kg body weight）30 minutes before each injection of cerulein. Lipid peroxidation,protein oxidation（carbonyl groups）, total antioxidant status,and glutathione peroxidase activity were determined in pancreatic tissue using commercial kits.RESULTS： The chemopreventive administration of melatonin caused a reduction in lipid peroxidation and protein oxidation due to injections of cerulein. Additionally, melatonin treatment was also able to revert glutathione peroxidase activity and total antioxidant status near to control levels, suggesting that melatonin could prevent from oxidative phenomena in the pancreas, such as lipid peroxidation and protein oxidation,and could stimulate, directly or indirectly, the expression of antioxidant enzymes.CONCLUSION： Melatonin, a polyvalent antioxidant, protected the pancreatic damage via the decrease of oxidative stress andincrease of the activities of antioxidant enzymes in ceruleininduced acute pancreatitis.

Oxidative stress and inflammatory signaling in cerulein pancreatitis

Oxidative stress is considered to be an important regulator of the pathogenesis of acute pancreatitis.Reactive oxygen species(ROS)regulate the activation of inflammatory cascades,the recruitment of inflammatory cells and tissue damage in acute pancreatitis.A hallmark of the inflammatory response in pancreatitis is the induction of cytokine expression,which is regulated by a number of signaling molecules including oxidant-sensitive transcription factors such as nuclear factor-κB(NF-κB)and activator protein-1(AP-1),signal transducer and activator of transcription 3(STAT3),and mitogen-activated protein kinases(MAPKs).Cross-talk between ROS and pro-inflammatory cytokines is mediated by NF-κB,AP-1,STAT3,and MAPKs;this crosstalk amplifies the inflammatory cascade in acute pancreatitis.Therapeutic studies have shown that antioxidants and natural compounds can have beneficial effects for patients with pancreatitis and can also influence the expression of proinflammatory cytokines in cerulein-induced pancreatitis.Since oxidative stress may activate inflammatory signaling pathways and contribute to thedevelopment of pancreatitis,antioxidant therapy may alleviate the symptoms or prevent the development of pancreatitis.Since chronic administration of high doses of antioxidants may have deleterious effects,dosage levels and duration of antioxidant treatment should be carefully determined.

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.

Gardenia jasminoides protects against cerulein-induced acute pancreatitis

AIM: To investigate the effect of Gardenia jasminoides (GJ) on cerulein-induced acute pancreatitis (AP) in mice.METHODS: C57BL/6 mice weighing 18-20 g were divided into three groups.(1) Normal saline-treated group,(2) treatment with GJ at a dose of 0.1 g/kg,(3) treatment with GJ at a dose of 1 g/kg.GJ was administered orally (n = 6 per group) for 1 wk.Three hours later,the mice were given an intraperitoneal injection of cerulein (50 μg/kg),a stable cholecystokinin (CCK) analogue,every hour for a total of 6 h as described previously.The mice were sacrificed at 6 h after completion of cerulein injections.Blood samples were obtained to determine serum amylase,lipase and cytokine levels.The pancreas was rapidly removed for morphologic examination and scoring.A portion of pancreas was stored at -70℃ and prepared for the measurement of tissue myeloperoxidase (MPO) activity,an indicator of neutrophil sequestration,and for reverse-transcriptase PCR (RT-PCR) and real-time PCR measurements.RESULTS: Treatment with GJ decreased significantly the severity of pancreatitis and pancreatitis-associated lung injury.Treatment with GJ attenuated the severity of AP compared with saline-treated mice,as shown by reduction in pancreatic edema,neutrophil infiltration,serum amylase and lipase levels,serum cytokine levels,and mRNA expression of multiple inflammatory mediators.CONCLUSION: These results suggest that GJ attenuated the severity of AP as well as pancreatitis-associated lung injury.

Therapeutic effect of caffeic acid phenethyl ester on cerulein-induced acute pancreatitis

AIM: To evaluate the therapeutic role of caffeic acid phenethyl ester (CAPE) in a rat model of ceruleaninduced acute pancreatitis (AP).METHODS: Seventy male Wistar albino rats were divided into seven groups. Acute edematous pancreatitis was induced by subcutaneous cerulein injection (20 μg/kg) four times at 1-h intervals. CAPE (30 mg/kg) was given by subcutaneous injection at the beginning (CAPE 1 group) and 12 h after the last cerulein injection (CAPE 2 group). Serum amylase, lipase, white blood cell count, and tumor necrosis factor (TNF)-α levels were measured, and pancreatic histopathology was assessed. RESULTS: In the AP group, amylase and lipase levels were found to be elevated and the histopathological evaluation showed massive edema and inflammation of the pancreas, with less fatty necrosis when compared with sham and control groups. Amylase and lipase levels and edema formation decreased signif icantly in the CAPE therapy groups (P < 0001); especially in the CAPE 2 group, edema was improved nearly completely (P = 0001). Inflammation and fatty necrosis were partially recovered by CAPE treatment. The pathologicalresults and amylase level in the placebo groups were similar to those in the AP group. White blood cell count and TNF-α concentration was nearly the same in the CAPE and placebo groups.CONCLUSION: CAPE may be useful agent in treatment of AP but more experimental and clinical studies are needed to support our observation of benef icial effects of CAPE before clinical usage of this agent.

Expression of early growth response factor-1 in rats with cerulein-induced acute pancreatitis and its significance

AIM: To observe the expressions of early growth response factor-1 (Egr-L) and tissue factor (TF) in rats with cerulein-induced acute pancreatitis and to explore its significance.METHODS: A large dose of cerulein was used to create the experimental acute pancreatitis model in rats. The changes of Egr-1 mRNA and protein in rats were observed during 30 min to 4 h after the treatment and immunohistochemical method was used to observe the localized expression of Egr-1 in tissues. In addition to the mRNA expression of Egr-1 target gene, TF was also observed. A blank control group, and a bombesinadministered group were used for comparison.RESULTS: After the stimulation of a large dose of cerulein,the rats showed typical inflammatory changes of acute pancreatitis. Thirty minutes after the stimulation, the mRNA expression of Egr-1 in the pancreatic tissue reached its peak and then declined, while the expression of Egr-1protein reached its peak 2 h after the stimulation.Histologically, 2 h after the stimulation, almost all pancreatic acinar cells had the expression of Egr-1 protein,which was focused in the nuclei. The mRNA expression of TF occurred 1 h after the stimulation and gradually increased within 4 h. However, a large dose of bombesin only stimulated the pancreatic tissue to produce a little mRNA expression of Egr-1 and no mRNA expression of Egr-1 protein and TF.CONCLUSION: Egr-1 as a pro-inflammatory transcription factor may play an important role in the pathogenesis of acute pancreatitis by modulating the expression of TF.

Differences in platelet endothelial cell adhesion molecule-1 expression between peripheral circulation and pancreatic microcirculation in cerulein-induced acute edematous pancreatitis

AIM: To investigate the changes of platelet endothelial cell adhesion molecule-1 (PECAM-1) expression on polymorphonuclear leukocytes (PMNs) in peripheral circulation and pancreatic microcirculation in cerulein-induced acute edematous pancreatitis (AEP).METHODS: Fifty Wistar rats were randomly divided into control group (n=10) and AEP group (n=40). A model of AEP was established by subcutaneous injection of cerulein 5.5 and 7.5 μg/kg at 0 and 1 h after the beginning of experiment respectively. PECAM-1 expression on PMNs from splenic vein and inferior vena cava was determined by RT-PCR at mRNA level and determined by flow cytometry at protein level.RESULTS: In experimental rats, an increased PECAM-1mRNA expression was seen from 4 to 8 h of AEP in peripheral circulation (0.77±0.25%, 0.76±0.28%, 0.89±0.30%,1.00±0.21% ), while in pancreatic microcirculation,expression decreased from 2 h and reached the lowest level at 6 h of AEP (0.78±0.29%, 0.75±0.26%, 0.62±0.28%,0.66±0.20%). There were significant differences at 8-h time point of AEP between peripheral circulation and pancreatic microcirculation (1.00±0.21% vs0.66±0.20%, P＜0.05).Meanwhile,the difference at protein level was also found.CONCLUSION: A reverse expression of PECAM-1 on PMNs was found between peripheral circulation and pancreatic microcirculation, suggesting that inhibition of PECAM-1expression may improve the pathological change of AEP.

三种急性胰腺炎大鼠模型的制备及特点比较

背景:建立稳定可靠的急性胰腺炎动物模型对于了解其发病机制、病理生理学特点及临床用药具有重大意义。国内外研究表明,雨蛙素、L-精氨酸、牛磺胆酸钠均能诱导急性胰腺炎,但是其病理生理学特点、模型特点变化规律尚不明确。目的:采用雨蛙素、L-精氨酸、牛磺胆酸钠制备大鼠急性胰腺炎模型,观察不同时段模型特点变化规律。方法:96只健康雄性SD大鼠随机分为正常组、雨蛙素组、L-精氨组、牛磺胆酸组,每组24只,每组内分为12,24,48 h 3个亚组,每个亚组8只。正常组不做处理,其余3组制备急性胰腺炎模型:雨蛙素组采用雨蛙素6次腹腔注射,间隔1 h;L-精氨酸组采用L-精氨酸2次腹腔注射,间隔1 h;牛磺胆酸钠采用胆胰管逆行注射牛磺胆酸钠诱导急性胰腺炎模型。考察各组大鼠存活率、胰腺大体形态、胰腺脏器指数、淀粉酶、脂肪酶、谷丙转氨酶、谷草转氨酶、尿素氮、肌酐水平,苏木精-伊红染色观察胰腺组织病理特征并进行胰腺损伤评分,评估大鼠不同时段模型特点变化规律。结果与结论:(1)雨蛙素组大鼠总存活率100%,L-精氨酸组为88%,牛磺胆酸钠组为96%;(2)各组模型大鼠胰腺脏器指数均有所升高;雨蛙素组大体观察可见胰腺水肿、分叶模糊、疏松;L-精氨酸组胰腺腺体增大增厚并伴有点片状出血;牛磺胆酸钠胰腺组织出现不同程度充血水肿伴散在点片状出血坏死;(3)各组模型组大鼠血清谷丙转氨酶、谷草转氨酶、尿素氮、肌酐水平与淀粉酶、脂肪酶水平变化一致,雨蛙素组可能在12 h达到峰值(P <0.05),随后呈下降趋势;L-精氨酸24 h达到最高峰(P <0.05),48 h明显下降;牛磺胆酸钠组血清淀粉酶、脂肪酶在12 h维持在较高水平并且有缓慢下降的趋势(P <0.05);(4)与正常组相比,光镜下观察雨蛙素组胰腺腺泡轻度水肿,小叶间隙增宽,炎性细胞较多;L-精氨酸组小叶间隙增宽,大量炎性细胞浸润,片状坏死点;牛磺胆酸钠组胰腺水肿明显,结构紊乱,出现大量坏死灶及炎性细胞浸润;(5)与正常组相比,3种模型诱导急性胰腺炎胰腺病理评分在各个时间点差异均有显著性意义(P <0.05),且同组随着时间的推移病理评分增加,说明胰腺组织损害逐渐加重;同一时间不同模型组相比,病理评分存在差异,且以牛磺胆酸钠组病理评分最高,L-精氨酸组次之,雨蛙素组最低;(6)结果提示,在相同时间点分析3种模型,病情最重的是牛磺胆酸钠组,以胰腺的出血坏死为主要特征;其次是L-精氨酸组,以坏死为主要特征,病情最轻为雨蛙素组,以水肿为主要特征;雨蛙素和L-精氨酸组血清生化指标在48 h有所好转,提示这两种模型可能有自愈倾向属于自限性病程;牛磺胆酸钠组血清生化指标在12 h后缓慢下降,因此认为在48 h后或者更长时间内牛磺胆酸钠组胰腺的损伤可能不会有所缓解。

吲哚美辛通过恢复自噬流减轻雨蛙素诱导的小鼠急性胰腺炎

目的探究吲哚美辛对雨蛙素诱导的小鼠急性胰腺炎(AP)的影响。方法将28只C57BL/6小鼠随机分为对照组、吲哚美辛组、雨蛙素组、雨蛙素+吲哚美辛组,通过雨蛙素(50μg/kg)腹腔注射法建立小鼠AP模型,雨蛙素+吲哚美辛组在第一次雨蛙素注射前6 h和0.5 h给予2次吲哚美辛(8 mg/kg)腹腔注射。HE染色观察小鼠胰腺组织形态学改变并进行组织病理学评分;检测血清淀粉酶与脂肪酶水平;免疫组化检测髓过氧化物酶阳性(MPO+)细胞数;qPCR检测炎症因子mRNA表达;电镜检测各组自噬空泡数量;Western blotting检测自噬相关蛋白LC3-Ⅱ与P62的表达。结果与对照组相比,雨蛙素组组织病理学评分增加(P<0.05);血清淀粉酶与脂肪酶明显升高(P<0.05);MPO+细胞数及炎症因子mRNA的表达水平升高(P<0.05);自噬空泡增多,LC3-Ⅱ与P62蛋白表达升高(P<0.05)。与雨蛙素组相比,雨蛙素+吲哚美辛组胰腺组织炎症样变减轻,组织病理学评分降低(P<0.05);血清淀粉酶与脂肪酶水平明显降低(P<0.05);MPO+细胞数及炎症因子mRNA的表达水平降低(P<0.05);异常堆积的自噬空泡减少,LC3-Ⅱ与P62蛋白的表达也下降(P<0.05)。结论本研究发现吲哚美辛可以减轻雨蛙素诱导的小鼠胰腺组织损伤并改善AP时受损的自噬流,提示吲哚美辛可能通过恢复受损的自噬流发挥其对小鼠AP的保护作用。

三种慢性胰腺炎大鼠模型的观察与比较

目的观察与比较雨蛙素注射、胰胆管结扎及精氨酸注射三种慢性胰腺炎造模方法。方法将大鼠随机分入雨蛙素注射（Cerulein）组，胰胆管结扎（Ligatjon）组，精氨酸注射组（Arginine）。采取相应方法制作慢性胰腺炎动物模型，在造模后3d、7d、14d三个时间点检测血淀粉酶、丙氨酸氨基转氨酶、血糖水平，ELISA法检测血清TNF—a，IL—1b水平，获取胰腺组织标本，对胰腺水肿、炎症、出血、腺泡坏死进行病理评分，应用VanGieson染色法对胰腺胶原纤维染色。RT—PCR法检测TGF_b表达。结果造模后各时间点，各组丙氨酸氨基转氨酶、血糖、TNF-a、IL-1b水平无明显差异，注射后3d，Cerulein组胰腺病理评分明显低于Ligation组和Arginine组。三组均可见胰腺组织胶原染色。Cerulein组3d时TGF-b表达低于Ligation组。结论三种造模方法各有优劣，但精氨酸注射法简便易行。

大鼠急性重症胰腺炎模型的建立

急性重症胰腺炎是一临床急重症,其死亡率高,预后差,深入开展对急性重症胰腺炎早期病理生理变化的研究,对于早期干预治疗,降低死亡率有着重要的意义,为此我们在国内首次建立了便于研究其早期病理生理变化及防治效果的大鼠急性重症胰腺炎模型.1材料和方法1.1材料 SD 大鼠,♂,320 g～390 g,由北京医科大学实验动物中心提供.将18只 SD 大鼠随机分为 ASP 组12只;假手术(sham operation,SO)组6只.蛙皮素(cerulein),Sigma 产品;甘脱氧胆酸(glycodeoxycholic acid),Sigma 产品;

雨蛙肽联合脂多糖诱导重度急性胰腺炎体外细胞模型钙通道的变化

目的应用雨蛙肽联合脂多糖诱导AR42J细胞构建重度急性胰腺炎体外细胞模型,研究该模型构建前后细胞内钙通道的变化。方法体外培养大鼠AR42J细胞,实验分组设对照组、雨蛙肽处理组、雨蛙肽+脂多糖处理组。采用RT-PCR检测细胞Cav1.3、Cav2.1、Cav2.2、Cav3.1、Cav3.2 mRNA表达;Western blotting检测细胞Cav1.3、Cav2.1、Cav3.1蛋白表达水平;以荧光探针Fluo-4-AM标记细胞内游离钙,激光共聚焦扫描显微镜观察[Ca2+]i的变化。结果药物处理组Cav1.3、Cav2.1、Cav3.1 mRNA及蛋白表达水平较对照组均明显增高(mRNA:F=23.392,46.85,61.338;蛋白:F=33.798,43.588,79.467;P<0.01),雨蛙肽+脂多糖处理组与雨蛙肽处理组相比较上述检测指标的mRNA表达量也显著增高(P<0.01);药物处理组与对照组Cav2.2、Cav3.2mRNA表达水平无明显差异(F=0.175、0.316;P>0.05);激光共聚焦显微镜观察结果显示药物处理组比对照组[Ca2+]i升高(F=638.984,P<0.01),雨蛙肽+脂多糖处理组较雨蛙肽处理组[Ca2+]i也显著升高(P<0.01)。结论胰腺腺泡细胞内钙超载在雨蛙肽联合脂多糖诱导的重度AP细胞模型发生发展的机制中具有重要作用。

肝细胞生长因子对小鼠轻症急性胰腺炎影响的实验研究

背景:及时、有效地控制轻症急性胰腺炎可防止其向重症急性胰腺炎演变,因而具有重要的临床价值。近年来,肝细胞生长因子(HGF)能否减轻啮齿动物的急性胰腺炎正日益受到关注。目的:观察外源性HGF能否减轻小鼠轻症急性胰腺炎,并探讨其作用机制。方法:以雨蛙肽腹腔注射诱发小鼠轻症急性胰腺炎,在制模前和制模中予各组小鼠皮下注射不同浓度的重组人HGF(rhHGF),部分小鼠同时皮下注射抗rhHGF单抗。根据血清淀粉酶、脂肪酶水平、胰腺组织学炎症评分和胰腺超微结构的变化评估炎症程度,并测定胰腺匀浆中花生四烯酸代谢产物血栓素(TX)B2和6鄄酮(keto)鄄前列腺素(PG)F1α的水平。结果:与单纯炎症组相比,给予4μg/kg或20μg/kgrhHGF小鼠的血清淀粉酶、脂肪酶水平和胰腺组织学炎症评分显著降低,胰腺匀浆中TXB2水平显著降低,6鄄keto鄄PGF1α水平显著增高,但4μg/kg与20μg/kgrhHGF的疗效无显著差异。给予rhHGF的同时给予抗rhHGF单抗,小鼠的上述各项参数与单纯炎症组无显著差异。结论:外源性HGF能减轻雨蛙肽诱导的小鼠轻症急性胰腺炎,其机制可能与对花生四烯酸代谢的影响有关。抗HGF单抗能抵消HGF的生物学作用。

高脂血症对大鼠急性胰腺炎发生的影响

目的 :研究高脂血症对大鼠急性胰腺炎发生的影响 ,即高脂血症是否是急性胰腺炎的高危因素。方法 :在中剂量Cerulein造成一定比例的急性胰腺炎发病率的基础上 ,通过研究高脂血症对急性胰腺炎发病率的影响来确定高脂血症是否是急性胰腺炎的高危因素。Wistar雄性大鼠随机分为 :①Bal组 ,均衡饲料饲养 2w ;②NS组 ,均衡饲料饲养 2w ,手术日腹腔注射生理盐水 0 .5ml/kg ,每小时 1次 ,共 4次 ;③M组 ,均衡饲料饲养 2w ,手术日腹腔注射Cerulein 10 μg/kg(0 .5ml/kg) ,每小时 1次 ,共 4次 ;④H组 ,高脂饲料饲养 2w ;⑤H +NS组 ,高脂饲料饲养 2w ,手术日腹腔注射生理盐水 0 .5ml/kg ,每小时 1次 ,共 4次 ;⑥H +M组 ,高脂饲料饲养 2w ,手术日腹腔注射Cerulein 10 μg/kg(0 .5ml/kg) ,每小时 1次 ,共 4次。剖腹主动脉采血检测血清淀粉酶、血甘油三脂 ,并取胰腺组织做胰腺病理切片观察。结果 :高脂血症增加急性胰腺炎的发病率 ,H +M组与M组有明显差异 (P <0 .0 5 )。结论 :较正常稍高的高脂血症并不能单独诱发急性胰腺炎 ,但是增加Cerulein诱发的急性胰腺炎的发病率 ,证明高脂血症是急性胰腺炎的高危因素。

Stress kinase inhibition modulates acute experimental pancreatitis

AIM To examine the role of p38 during acute experimental cerulein pancreatitis.METHODS Rats were treated with cerulein with or without a specific JNK inhibitor (CEP1347)andy or a specific p38 inhbitor (SB203380) and pancreatic stress kinase activity wasdetermined. Parameters to assess pancreatitis included trypsin, amylase, lipase, pancreatic weight and histology.RESULTS JNK inhibition with CEP1347ameliorated pancreatitis, reducing pancreatic edema. In contrast, p38 inhibition with SB203580aggravated pancreatitis with higher trypsinlevels and, with induction of acinar necrosis not normally found after cerulein hyperstimulation.Simultaneous treatment with both CEP1347 and SB203580 mutually abolished the effects of either compound on cerulein pancreatitis.CONCLUSION Stress kinases modulatepancreatitis differentially. JNK seems to promote pancreatitis development, possibly by supporting inflammatory reactions such as edema formation while its inhibition ameliorates pancreatitis. In contrast, p38 may help reduce organ destruction while inhibition of p38 during induction of cerulein pancreatitis leads to the occurrence of acinar necrosis.

肝细胞生长因子对实验性急性胰腺炎细胞凋亡作用的研究

目的:观察外源性肝细胞生长因子(HGF)对小鼠轻症实验性急性胰腺炎的炎症反应及胰腺细胞凋亡的作用。方法:以雨蛙肽腹腔注射诱发小鼠轻症实验性急性胰腺炎。第1组以盐水腹腔注射作为对照,第2、3及4组每小时腹腔注射雨蛙肽诱发急性胰腺炎;第3组在造模前及造模中两次皮下注射重组人肝细胞生长因子(rhHGF);第4组同时皮下注射rhHGF及其单抗。观察HGF对炎症反应的干预作用及对腺泡细胞凋亡的影响。结果:炎症小鼠予每公斤体重4、20μgrhHGF时,与单纯炎症组相比,血清淀粉酶、脂肪酶下降,胰腺组织学炎症评分减少,胰腺腺泡细胞TUNEL凋亡指数增加,caspase3活性增强。予每公斤体重4或20μgrhHGF时,其效应无显著性差异。同时予rhHGF单抗的小鼠,上述指标与单纯炎症组相比差异无显著性。结论:HGF能减轻雨蛙肽诱导的小鼠轻症实验性急性胰腺炎。HGF单抗能消除HGF的生物学作用。HGF可以促进急性胰腺炎时腺泡细胞的凋亡,这可能是其保护胰腺的作用机制之一。

棕榈酸对雨蛙肽诱导的大鼠胰腺腺泡细胞炎症早期基因表达谱的影响

背景：高三酰甘油血症是急性胰腺炎的发病原因之一。血浆中增多的游离脂肪酸(FFA)可损伤多种细胞,导致细胞功能障碍,可能在高三酰甘油血症性急性胰腺炎的发生、发展中起重要作用。目的：探讨饮食中的主要FFA棕榈酸对雨蛙肽诱导的大鼠胰腺腺泡细胞炎症早期基因表达谱的影响。方法：以胶原酶消化法分离大鼠胰腺腺泡细胞,将细胞分为3组,雨蛙肽组加入终浓度为100 nmol/L的雨蛙肽．雨蛙肽+棕榈酸组加入相同剂量的雨蛙肽和终浓度为1 mmol/L的棕榈酸,正常对照组不予处理。培养3h后提取细胞总RNA,应用含15000余条大鼠基因的大鼠Affymetrix 230A基因芯片检测基因表达谱的变化。结果：雨蛙肽+棕榈酸组较雨蛙肽组出现30条上调基因和15条下调基因,其功能涉及细胞信号转导、转录、脂质代谢、蛋白修饰等不同层次。结论：棕榈酸可能通过影响大鼠炎症胰腺腺泡细胞多种结构和功能基因的表达而加重其损伤。

雨蛙素腹腔注射致小鼠慢性胰腺纤维化病理组织学观察

目的:采用雨蛙素反复腹腔注射诱导小鼠慢性胰腺炎,评估胰腺发生纤维化的程度及病变特点。方法:健康雄性C57BL/6小鼠20只,随机分为两组,模型组反复腹腔注射雨蛙素,对照组腹腔注射与模型组等体积的生理盐水,于第7周第1 d留取胰腺组织,光镜下进行胰腺腺泡细胞萎缩、炎性细胞浸润、间质纤维组织增生评分;另一部分行苦味酸-天狼星红染色,偏振光显微镜下观察胰腺间质胶原增生情况;第三部分行免疫组织化学染色,观察α-SMA表达情况。结果:模型组小鼠胰腺HE染色显示明显腺泡细胞萎缩、炎性细胞浸润及纤维化;苦味酸-天狼星红染色显示显著胰腺间质胶原增生,评分明显升高;免疫组织化学染色显示星状细胞活化标志物α-SMA表达明显增强。结论:雨蛙素反复多次腹腔注射可诱导小鼠产生明显的胰腺纤维化病变,纤维化发生机制可能与胰腺星状细胞活化分泌过多细胞外间质有关。

脂氧素受体激动剂BML-111对小鼠重症急性胰腺炎影响的实验研究

目的探讨脂氧素受体激动剂BML-111对小鼠重症急性胰腺炎的影响及可能机制。方法128只健康雄性Babl／cdx鼠随机分为4组，即①生理盐水对照组（NS组），②BML-111对照组（BML组）；③重症急性胰腺炎组（SAP组）；④BML-111治疗组（SAP＋BML组），每组又分为3h．6h、12h及24h共4个亚组，每组8只小鼠；采用蛙皮素联合脂多糖腹腔注射法建立小鼠SAP模型。SAP＋BML组及BML组分别于第一次注射前1h经腹腔注射BML-111。分别于最后一次注射后3h．6h、12h、24h处死小鼠采集标本，采用对-硝基苯麦芽七糖苷法检测血清淀粉酶（AMY）水平；双抗体夹心ELISA法检测血清C反应蛋白（CRP）、IL-10、TNF—α、IL-1β含量；胰腺组织行苏木素～伊红染色（H-E染色）并行病理学评分。结果与Ns组及BML组各对应时相点比较，SAP组小鼠血清淀粉酶、CRP、TNF-α、IL-1β水平均显著增加（P〈0．05）；血清IL-10水平下降（P〈0．05）；胰腺H—E染色均符合SAP的表现；胰腺组织的病理学损伤评分亦均显著增高（P〈0．05）。与SAP组各对应时相点比较，SAP＋BML组小鼠血清AMY、CRP、TNF—α、IL—1β及胰腺的病理学损伤评分均明显降低（P〈0．05）；血清IL-10水平则增高（P〈0．05）；胰腺组织病理学改变亦较SAP组有所改善。结论BML-111预处理对蛙皮素诱导的小鼠重症急性胰腺炎具有一定的保护作用，这种作用可能与BML-111对促炎因子TNF-α、IL-lβ及抗炎因子IL一10的调节有关。