葡聚糖硫酸钠诱导大鼠结肠炎发病机制的研究

背景:葡聚糖硫酸钠(DSS)可诱导大鼠结肠炎,但其发病机制尚不完全清楚。目的:探讨DSS诱导大鼠结肠炎的发病机制。方法:16只健康雄性Sprague-Dawley大鼠随机分成DSS模型组(10只)和正常对照组(6只),DSS模型组大鼠自由饮用2％DSS溶液8天,正常对照组大鼠正常饮水。于第9天处死大鼠,采用酶联免疫吸附测定(ELISA)方法测定血清肿瘤坏死因子(TNF)-α和白细胞介素(IL)-6水平,采用免疫组化方法测定结肠黏膜细胞间黏附分子(ICAM)-1的表达和核因子(NF)-κB活性。结果:DSS模型组大鼠出现腹泻、便血以及结肠黏膜糜烂或溃疡,血清TNF-α和IL-6水平以及结肠黏膜ICAM-1表达和NF-κB活性均较正常对照组显著增高(P<0.01)。结论:在DSS诱导的大鼠结肠炎中,DSS可能通过活化NF-κB使TNF-IL-6和ICAM-1生成增加,导致结肠黏膜炎性损害和腹泻、便血。     

罗格列酮对大鼠溃疡性结肠炎肠黏膜NF-κB,ICAM-1表达的影响

目的:探讨罗格列酮对大鼠溃疡性结肠炎肠黏膜核转录因子-κB(NF-κB),细胞间黏附分子-1(ICAM-1)表达的影响.方法:应用三硝基苯磺酸(TNB)/乙醇灌肠制备大鼠溃疡性结肠炎模型.实验设正常对照组,模型对照组,阳性药物组(柳氮磺吡啶SASP组,100mg/kg),罗格列酮组(2,4,8mg/kg),每天灌胃给药1次,给药时间从造模后第2天开始至实验结束共8d,观察大鼠疾病活动指数(DAI)和结肠黏膜损伤指数(CMDI),生化法检测大鼠结肠组织髓过氧化酶(MPO)活性,免疫组化法检测大鼠肠黏膜NF-κBp65和ICAM-1蛋白的表达.结果:与正常组相比,模型组DAI、CMDI评分及结肠组织MPO活性明显升高(2.11±1.29vs0.11±0.17,2.67±0.82vs0.33±0.52,1.26±0.36U/gvs0.27±0.07U/g,P<0.01),结肠黏膜NF-κBp65及ICAM-1表达明显增强(0.7081±0.0671vs0.2293±0.0474;0.4846±0.0366vs0.1783±0.0201,P<0.01).罗格列酮中、高剂量组DAI,CMDI评分及MPO活性较模型组有明显下降(DAI:1.11±0.50,0.61±0.25vs2.11±1.29,P<0.05;CMDI:1.67±0.52,1.17±0.75vs2.67±0.82,P<0.05;MPO:0.82±0.13,0.51±0.10U/gvs1.26±0.36U/g,P<0.01),NF-κB及ICAM-1表达也有不同程度降低(NF-κB:0.4544±0.0379,0.2577±0.0131vs0.7081±0.0671,P<0.01;ICAM-1:0.3854±0.0277,0.2830±0.0234vs0.4846±0.0366,P<0.01).大鼠结肠黏膜NF-κB的表达与ICAM-1表达呈正相关(r=0.927,P<0.01),ICAM-1的表达与结肠组织MPO活性也呈正相关(r=0.580,P<0.01).结论:罗格列酮对大鼠溃疡性结肠炎有保护作用,其作用机制可能与抑制NF-κB活化,减少黏附分子ICAM-1产生以及降低中性粒细胞浸润有关.     

氧化苦参碱对葡聚糖硫酸钠诱导大鼠结肠炎的抗炎作用机制研究

目的　探讨氧化苦参碱 (OM )对葡聚糖硫酸钠 (DSS)诱导结肠炎的抗炎作用及其作用机制。方法　建立DSS诱导的大鼠结肠炎模型。SD大鼠 2 6只 ,随机分为OM处理组 (A组 ,10只 )、OM未处理组 (B组 ,10只 )和正常对照组 (C组 ,6只 )。A组第 1～ 11天肌内注射OM 6 3mg·kg-1·d-1,第 4～ 11天饮用 2 %DSS溶液 ;B组第 1～ 11天肌注与A组OM等体积的生理盐水 ,第 4～ 11天饮用 2 %DSS溶液 ;C组肌注生理盐水同B组 ,正常饮水。观察大鼠的腹泻、便血症状及结肠组织学改变 ,ELISA测定血清肿瘤坏死因子 α(TNF α)和白细胞介素 6 (IL 6 )水平 ,免疫组化检测结肠黏膜核转录因子 κB(NF κB)活性及细胞间粘附分子 1(ICAM 1)的表达。结果　与OM未处理组相比 ,OM处理组大鼠的症状和结肠黏膜组织学损伤显著改善 (P值均 <0 .0 5 ) ,TNF α ,IL 6 ,NF κB和ICAM 1显著降低 (P值均 <0 .0 5 )。结论　OM可抑制NF κB活化 ,降低TNF α、IL 6和ICAM 1的生成 ,从而减轻结肠炎性损伤和腹泻、便血症状。     

乌梅丸对溃疡性结肠炎大鼠肠组织核转录因子-κB及细胞间黏附分子1的影响

[目的]探讨乌梅丸对大鼠溃疡性结肠炎（UC）结肠组织核转录因子-κB（NF-κB）及细胞间黏附分子1（ICAM-1）表达的影响机制。[方法]采用2，4-二硝基氯苯（DNCB）加醋酸复合法制备大鼠UC模型。84只SD大鼠随机分为正常对照（正常）组、模型组、柳氮磺胺吡啶（SASP）组和乌梅丸大、中、小剂量组。采用免疫组织化学染色法检测结肠组织NF-κB、ICAM-1的表达。[结果]与正常组相比，模型组大鼠结肠组织中NF-κB、ICAM-1表达显著增高（P〈0．01），而乌梅丸各剂量组、SASP组较模型组明显降低（P〈O．01）。[结论]NF-κB、ICAM-1可能参与了UC的发生、发展。乌梅丸可能通过抑制NF-κB、ICAM-1的表达，从而起到治疗UC的作用。     

NF-κB、iNOS在大鼠实验性结肠炎肠组织的表达及意义

目的观察大鼠实验性溃疡性结肠炎肠组织核因子-κB(NF-κB)及iNOS、NO的表达,探讨NF-κ:B在溃疡性结肠炎发病过程中的作用.方法采用三硝基苯磺酸(TNBS)制备大鼠溃疡性结肠炎模型,动物分为正常组、生理盐水组及轻、重模型组共4组.采用免疫组织化学染色检测肠组织NF-κB、iNOS表达,生化方法检测MPO、NO含量,并分析NF-κ:B活性与肠道病理损伤指数、MPO、NO含量及iNOS表达的关系.结果与正常组及生理盐水组相比,溃疡性结肠炎大鼠肠组织中NF-κB活性,iNOS表达及NO含量、MPO活性显著增高(P＜0.01),且在病情严重组增高尤为明显.NF-κ:B表达水平与iNOS阳性细胞密度、NO含量、MPO活性及肠道病理损伤指数呈显著正相关关系(P＜0.01).结论NF-κ:B、iNOS可能参与了溃疡性结肠炎发生、发展.     

布拉酵母菌对溃疡性结肠炎大鼠核因子-κB及肿瘤坏死因子-α表达的影响

目的观察布拉酵母菌(亿活)对溃疡性结肠炎(UC)大鼠核因子(NF)-κB与肿瘤坏死因子(TNF)-α表达的影响。方法健康Wistar大鼠30只随机分为对照组、模型组、美沙拉秦(莎尔福)组、亿活组、联合治疗组各6只。对照组:大鼠2 ml生理盐水灌肠;模型组、莎尔福组、亿活组、联合治疗组均需要制备UC模型;莎尔福组、亿活组、联合治疗组采用相应治疗,运用酶联免疫吸附试验检测各组大鼠肠组织中NF-κB和TNF-α的表达情况。结果莎尔福组、亿活组及联合治疗组NF-κB与TNF-α水平均明显低于模型组(均P<0. 05)。联合治疗组NF-κB与TNF-α水平明显低于莎尔福组及亿活组(均P<0. 05)。结论亿活与莎尔福均抑制NF-κB与TNF-α活性,起到抗感染治疗作用,联合用药效果更佳。     

活血健脾补肾法对结肠炎小鼠结肠组织TNF-α及其mRNA表达的影响

目的:观察TNF-α及其mRNA在结肠炎小鼠结肠组织的表达,探讨活血健脾补肾法方药对其影响．方法:用右旋葡聚糖硫酸钠(DSS)诱导小鼠产生溃疡性结肠炎模型．将小鼠随机分为空白对照、模型、柳氮磺胺吡啶(SASP)、活血法、健脾法及补肾法组;免疫组化、原位杂交法分别观察治疗后小鼠结肠组织TNF-α及其mRNA的表达．结果:模型组小鼠结肠组织学损伤积分(炎症、病度深度、隐窝破坏)分别为4．85±2．1,5．77±2．2,7．76±2．4;活血法组 (2．24±2．4,2．53±2．5,3．49±2．3)、健脾法组(2．76 2．2,2．89±2．4, 3．87±2．3)、补肾法组(2．12±2．3,2．33±2．2,3．44±2．4)与模型组比较有显著意义(4．85±2．1,5．77±2．2,7．76±2．4)(均 P<0．05)．模型组小鼠结肠组织TNF-α及其mRNA的表达(染色积分、平均光密度、平均灰度)分别是6．8±1．4,0．35±0．03． 78．6±4．4;活血法组(3．7±1．1,0．18±0．05,137．9±6．7)、健脾法组(3．4±1．3,0．16±0．03,155．1±8．8)、补肾法组(3．1± 1．5,0．17±0．04,145．6．2±7．6)与模型组比较有显著意义(6．8± 1．4,0．35±0．03,78．6±4．4)(均P<0．05)．结论:TNF-α参与DSS诱导小鼠溃疡性结肠炎的形成,活血、健脾及补肾法方药通过下调TNF-α的表达发挥防治作用．     

小檗碱对糖尿病大鼠外周神经功能及神经病理性痛的影响

目的探讨小檗碱(Berberine,Ber)对糖尿病(DM)大鼠外周神经功能和神经病理性痛的影响及其作用机制。方法以链脲佐菌素(STZ)腹腔注射诱导形成DM模型,随机分成对照组、模型组和Ber组,其中Ber组给予187.5 mg/kg的Ber灌胃。用机械刺激法、热板法,分别测缩足反应阈值(MWT)、热痛阈值(HPT);电刺激诱导动作电位法测定坐骨神经传导速度(NCV);光镜观察脊髓组织形态学改变;用硝酸还原法、化学比色法测定一氧化氮(NO)、一氧化氮合酶(NOS)含量或活性。结果 DM大鼠MWT、HPT均明显降低(P<0.01),坐骨神经NCV明显减慢(P<0.05),脊髓背角萎缩,神经元变性坏死,核仁消失,尼氏小体消失,Ber组则明显恢复;DM大鼠血清、坐骨神经NO、NOS均明显减少(P<0.01),Ber组则明显升高(P<0.05)。结论 Ber能减轻DM大鼠神经病理性疼痛症状,维持外周神经的结构和功能,这种作用与其增加NOS活性,促进NO的合成和释放,抑制NO的灭活有关。     

c-Jun氨基末端激酶选择性抑制剂对葡聚糖硫酸钠诱导的小鼠结肠炎的影响

目的:探讨c-Jun氨基末端激酶(JNK)选择性抑制剂SP600125对葡聚糖硫酸钠(DSS)诱导的急性期溃疡性结肠炎小鼠结肠组织内肿瘤坏死因(TNF)α的表达情况及血清白介素(IL)-6含量的影响.方法:40R♂C57BL/6小鼠随机分成5组,每组8只.正常对照组(A组)、DSS模型组(B组)、SP600125低剂量...     

中药肠炎清治疗小鼠葡聚糖硫酸钠所致结肠炎的机制

目的:探讨肠炎清的疗效及其机制.方法:以葡聚糖硫酸钠(DSS)饮水法复制小鼠实验性结肠炎40只,随机平均分为4组:肠炎清中药组、柳氮磺胺吡啶(SASP)西药组、肠炎清和SASP中西药结合组和模型组.观察肠炎清(灌胃剂量为0.2mL/(20g?d)、1次/d、疗程7d)对疾病活动指数(DAI)和肠组织髓过氧化物酶(MPO)活性及TNF-α、IL-1β和IL-6mRNA表达的影响.结果:与模型组相比,肠炎清可降低DAI(1.413±0.835vs2.167±0.911,P<0.05)和MPO活性(72.4±0.590nkat/gvs117.0±0.902nkat/g,P<0.05),并降低肠组织TNF-α(0.841±0.190vs1.320±0.282,P<0.05)、IL-1β(0.641±0.095vs0.920±0.082,P<0.05)和IL-6mRNA(1.241±0.247vs1.620±0.312,P<0.05)的表达,中西医结合组以上指标下降更为明显(DAI:0.608±0.449;MPO:27.3±0.211;TNF-α:0.339±0.081;IL-1β:0.239±0.073;IL-6:0.639±0.141)(P<0.01).肠炎清与柳氮磺胺吡啶(SASP)的作用相当(P>0.05).结论:肠炎清可治疗DSS结肠炎,其降低肠组织TNF-α、IL-1β和IL-6mRNA的表达可能是其疗效机制之一.     

Rebamipide enema is effective for treatment of experimental dextran sulfate sodium induced colitis in rats

We investigated therapeutic efficacy of rebamipide using dextran sulfate sodium (DSS) induced colitis model in rats. Three percent DSS solution was given to rats for 9 days. After that, we evaluated the drug efficacy on colitis sustained with continuous drinking of 1% DSS. Twice-daily treatment with 0.3% or 1% rebamipide for 14 days significantly ameliorated the stool abnormality in the colitis model, preferentially suppressed hematochezia. The colonic mucosal lesion, determined by Alcian blue staining on day 24, was significantly reduced by rebamipide enema in a dose-dependent manner. Either rebamipide or 5-aminosalycilic acid (5-ASA) enema treated once daily significantly ameliorated colitis. The minimum effective dose of rebamipide was 0.3% in once-daily treatment, and that of 5-ASA was 10%. In a mechanistic study, the epithelial cell sheet formation of the T84 colon cancer cell was measured as an increase in generation of trans-epithelial electrical resistance in vitro. Rebamipide accelerated the increase, while 5-ASA conversely suppressed it. These results suggest that rebamipide enema is effective for treatment of experimental ulcerative colitis (UC).     

硝酸酯在小鼠急性实验性结肠炎中的治疗作用

目的 观察硝酸酯对小鼠急性实验性结肠炎的疗效.方法 将40只BALB/c小鼠均分为模型组和治疗组,模型组予4％葡聚糖硫酸钠(DSS)溶液,治疗组予4％DSS溶液和1.5 g/L硝酸酯溶液,均连续饮用7d.对小鼠疾病活动指数(DAI)进行评分.取小鼠结肠组织进行苏木精-伊红染色和髓过氧化物酶(MPO)免疫组织化学染色并进行观察.分别用MPO和一氧化氮检测试剂盒检测结肠组织MPO和一氧化氮活性.统计学处理采用t检验.结果 第6和第7天治疗组和模型组的DAI差异有统计学意义(t=5.12和6.72,P=0.012和0.008).第7天时模型组组织学评分(2.5±0.5)高于治疗组(1.9±0.4),差异有统计学意义(t=3.82,P＜0.01).与模型组相比,治疗组小鼠结肠组织病理损伤明显减轻,中性粒细胞浸润减少.第7天时模型组MPO活性、NO2-浓度、NO3-浓度分别为(2.8±0.6) U/g、(10.4±4.3) mmol/g、(100.3±50.1)mmol/g,治疗组则分别为(1.5±0.3)U/g、(17.5±7.0)mmol/g、(190.7±85.3) mmol/g,差异均有统计学意义(t=11.23、3.81、4.50,P均＜0.01).结论 硝酸酯可减轻DSS诱导的小鼠急性实验性结肠炎.     

Impaired nitrergic innervation in rat colitis induced by dextran sulfate sodium

BACKGROUND & AIMS: The pathophysiological role of neuronal nitric oxide synthase (nNOS) in colitis remains unknown. METHODS: We investigated colonic transit, nonadrenergic, noncholinergic (NANC) relaxation, nNOS activity, and nNOS synthesis in the myenteric plexus in dextran sulfate sodium (DSS)-induced colitis in rats. RESULTS: Oral administration of 5% DSS for 7 days induced predominant distal colitis and delayed colonic transit. In the proximal colon, carbachol-, sodium nitroprusside-, and electrical field stimulation (EFS)-induced responses were not different between control and DSS-treated rats. In the distal colon, EFS-evoked cholinergic contraction, NANC relaxation, and orphanin FQ-induced contraction were significantly impaired in DSS-treated rats compared with those in control rats, but carbachol- and sodium nitroprusside-induced responses remained intact in DSS-treated rats. The number of nNOS-immunopositive cells, catalytic activity of NOS, and nNOS synthesis in the colonic wall were significantly reduced in the distal colon of DSS-treated rats. In contrast, the number of PGP 9.5-immunopositive cells and PGP 9.5 synthesis in the colonic wall remained intact in the distal colon of DSS-treated rats. CONCLUSIONS: These results suggest that impaired NANC relaxation in the distal colon is associated with reduced activity and synthesis of nNOS in the myenteric plexus in DSS-induced colitis.     

Effect of adiponectin on murine colitis induced by dextran sulfate sodium

BACKGROUND & AIMS: Adiponectin, an adipose tissue-derived hormone, exhibits anti-inflammatory properties and has various biological functions, such as increasing insulin sensitivity, reducing hypertension, and suppressing atherosclerosis, liver fibrosis, and tumor growth. The aim of the present study was to determine the effect of adiponectin on intestinal inflammation. METHODS: We investigated the effect of adiponectin on dextran sulfate sodium (DSS)-induced colitis by using adiponectin-knockout (APN-KO) mice and an adenovirus-mediated adiponectin expression system. We also examined the contribution of adiponectin deficiency to trinitrobenzene sulfonic acid (TNBS)-induced colitis. In vitro, we examined the effect of adiponectin on intestinal epithelial cells. RESULTS: After administration of 0.5% DSS for 15 days, APN-KO mice developed much more severe colitis compared with wild-type mice. The messenger RNA expression levels of chemokines were significantly higher in the colonic tissues of DSS-treated APN-KO mice compared with wild-type mice, accompanied by increased cellular infiltration, including macrophages. Adenovirus-mediated supplementation of adiponectin significantly attenuated the severity of colitis, but there were no differences in the severity of TNBS-induced colitis between the 2 groups. Adiponectin receptors were expressed in intestinal epithelial cells, and adiponectin inhibited lipopolysaccharide-induced interleukin-8 production in intestinal epithelial cells. CONCLUSIONS: Adiponectin is protective against DSS-induced murine colitis, probably due to the inhibition of chemokine production in intestinal epithelial cells and the following inflammatory responses, including infiltration of macrophages and release of proinflammatory cytokines.     

Intestinal blood flow in murine colitis induced with dextran sulfate sodium

The aim of this study was to assess whether colitis induced by dextran sulfate sodium (DSS; 10% in tap water for 7 days) in BALB/c mice is associated with changes in intestinal blood flow. After anaesthesia, systemic hemodynamic variable and regional blood flows and resistances in various organs were measured in both control and DSS-treated mice. Mean arterial blood pressure was significantly lower in DSS-treated mice than in controls (56 ± 4 vs 66 ± 3 mm Hg; P < 0.05), but no differences were found in regional blood flows to or vascular resistances in the lungs, liver, stomach, small intestine (upper, middle, and lower part), cecum, mesentery + pancreas, spleen, kidneys, brain, and skin. However, compared to the control mice, blood flows in the middle (0.88 ± 0.13 vs 0.55 ± 0.09 ml/min/g; P < 0.05) and distal (0.69 ± 0.11 vs 0.29 ± 0.05 ml/min/g; P < 0.05) colon were significantly higher, and vascular resistances in the proximal (0.87 ± 0.21 vs 1.36 ± 0.21 mm Hg min/ml/100 g; P < 0.05), middle (0.60 ± 0.10 vs 1.46 ± 0.35 mm Hg min/ml 100 g; P < 0.05) as well as distal (0.90 ± 0.25 vs 2.67 ± 0.49 mm Hg min/ml/100 g; P < 0.05) colon were significantly lower in mice with experimental colitis. Interestingly, there was a gradient in the intestinal blood flow in control mice from the upper small intestine (2.79 ± 0.72 ml/min/g) down to the distal colon (0.29 ± 0.05 ml/min/g); such a gradient was also present in the colitis mice. It is concluded that DSS-induced colitis in mice is associated with microcirculatory disturbances in the colon, mainly in its middle and distal parts.     

Immune response in mouse experimental cholangitis associated with colitis induced by dextran sulfate sodium

BACKGROUND AND AIM: Primary sclerosing cholangitis is frequently complicated by inflammatory bowel disease. Although many colitis models have been reported, little information has been obtained about complicated cholangitis. The aim of the present study was to determine whether hepatobiliary disorders occur in mice experimental colitis, and to clarify the underlying mechanisms. METHODS: The CD-1 mice were fed standard chow with or without dextran sulfate sodium in the drinking water, followed by histological examination of the liver and colon. Mononuclear cells were isolated from these organs, and cytokine production was assessed. The CD4/CD8 ratio and the population of natural killer T (NKT) cells were analyzed by flow cytometry. RESULTS: Inflammatory cell infiltration and focal necrosis in the liver were found in 33% of treated mice. In treated mice, the CD4/CD8 ratio increased in the liver, whereas no such change was found in the colon. Also an increase of interferon-gamma and a decrease of interleukin-4 production were observed. The NKT cell population showed transient changes in the liver and colon. CONCLUSIONS: Hepatobiliary disorders were complicated with experimental colitis in CD-1 mice. Immunological findings indicate a T-helper-1-dominant underlying mechanism, and NKT cells may play a pathogenic role in this model. This model may help to elucidate the relationship between hepatic and colonic inflammations.     

Direct autoradiographic evidence that rebamipide interacts with neutrophils in dextran sulfate sodium induced colitis in rats

To determine the effects of rebamipide during the early stages of colitits development, colitis was induced in rats by oral administration of dextran sulfate sodium for 3 or 7 days. The target sites of (3)H-rebamipide were examined by intra-aortic infusion of the radiolabeled compound followed by autoradiography. (3)H-rebamipide was localized in goblet cells in the colon of the control rat, whereas it accumulated in the cytoplasm of mesenchymal cells in dextran sulfate sodium treated rats, localized predominantly to polymorphonuclear leucocytes.