大鼠肠道DCs及相关细胞因子在冷-束缚应激诱导肠功能紊乱后的表达

目的:了解肠道表面树突状细胞(DCs)及炎症细胞因子VIP、IL-1β在肠功能紊乱时的表达,以及外周血中VIP、IL-1β的表达,探讨大鼠肠道免疫耐受的变化.方法:将60只Wistar大鼠随机分为实验组和对照组,建立冷-束缚应激动物模型.将大鼠处死后,取大鼠回肠末端、远端结肠各长约2 cm的肠段,免疫组织化学法检测肠道表面CD11c、VIP、IL-1β的表达,留取腹主动脉血清ELISA方法检测外周血清中VIP、IL-1β的表达.结果:在回肠末端,实验组大鼠CD11c的表达较对照组无显著差异性;实验组大鼠VIP、IL-1β表达较对照组均明显增加,差异有显著性(177.67±35.44 vs 92.64±22.19,359.56±45.48 vs 216.46±41.56,均P<0.05).并且VIP的表达与IL-1β呈正相关(r=0.78,P<0.01).在远端结肠,实验组大鼠CD11C、IL-1β的表达较对照组均无显著差异性;而实验组大鼠远端结肠VIP的表达较对照组明显增高,差异有显著性(380.15±33.24 vs 254.04±40.53.P<0.05);在外周血中,与对照组相比较,VIP、IL-1β表达均增高,差异有显著性(149.03 ng/L±56.82 ng/L vs 104.24 ng/L±39.03 ng/L,8.82 ng/L±3.91 ng/L vs 5.49 ng/L±3.79 ng/L.P<0.05).结论:冷-束缚应激后肠功能紊乱大鼠中,末端回肠和远端结肠黏膜存在轻度的炎症反应,DCs尚不能解释肠功能紊乱后肠道存在轻度炎症反应的发病机制.     

冷-束缚应激诱导肠功能紊乱大鼠肠黏膜屏障变化的实验研究

目的 建立冷-束缚应激(CRS)诱导肠功能紊乱大鼠模型,探讨肠黏膜屏障变化在肠功能紊乱发病机制中的可能作用.方法 选取2个月龄Wistar大鼠40只,随机分成模型组和正常对照组.模型组采用寒冷加束缚为应激源实施干预,对照组不予任何干预.实验期间观察两组大鼠粪便性状,应用Bristol分型进行评分,通过直结肠扩张(CRD)实验测定内脏敏感性,取大鼠远端结肠及回肠黏膜行病理组织学检查.采用气相色谱法(GC)测定两组大鼠5 h尿液中乳果糖(L)与甘露醇(M)排泄率(L/M)比值,反映肠黏膜屏障的变化情况.结果 模型组粪便多为软的团块状或泥浆样,对照组多为柔软的香肠状或团块状,两组大鼠Bristol分型评分比较有显著性差异(P＜0.05);模型组初始感觉阈值、疼痛感觉阈值、最大耐受阈值分别较对照组显著降低(P＜0.05);两组肠黏膜病理检查均未见明显异常;模型组大鼠5 h尿液中L与M排泄率比值(L/M)较对照组显著增大(P＜0.05).结论 肠功能紊乱大鼠肠黏膜通透性增大,肠黏膜屏障受损可能与肠功能紊乱发病机制有关.     

冰水灌胃应激建立便秘表现肠功能紊乱大鼠模型

背景:应激是引起肠功能紊乱的重要原因之一。建立适当的动物模型对于研究肠功能紊乱性疾病的病因和发病机制至关重要。目的:通过冰水灌胃应激建立便秘表现肠功能紊乱大鼠模型。方法:36只Sprague-Dawley大鼠随机分为6组,A1、A2组和B1、B2组分别予冰水和常温水灌胃14 d,C1、C2组不予灌胃,作为正常对照。A2、B2、C2组于灌胃结束后次日行小肠推进实验,A1、B1、C1组于灌胃期间和其后的14 d每日计数24 h粪便粒数,称量粪便质量,结束后次日行小肠推进实验。结果:冰水灌胃组第2周末24 h粪便粒数、质量和小肠墨汁推进率显著低于常温水灌胃组和正常对照组(P0.05),并保持至第4周末,组内第2周末与第4周末间差异无统计学意义。结论:以冰水灌胃应激建立的便秘表现肠功能紊乱大鼠模型能模拟人类肠功能紊乱且重复性、稳定性好,为相关疾病的研究提供了条件。     

福氏志贺菌感染后大鼠肠功能紊乱模型建立

目的建立福氏志贺菌感染后肠功能紊乱大鼠模型。方法将40只雄性Wistar大鼠随机分为实验组和对照组,实验组用5×109cfu/mL 4型福氏志贺菌2 mL灌胃,对照组大鼠予2 mL生理盐水灌胃。于灌胃后每日观察大鼠大便的性状,大便性状分级采用Bristol大便分级法。并于第1天、第3天、第14天、第21天行大便培养。并于第21天、42天和63天给大鼠行直结肠球囊扩张(CRD)观察其腹部回撤反射(AWR)评分来反映大鼠的内脏敏感性。上述实验结束后将所有大鼠处死,取末端回肠及近端结肠行组织病理学检查观察炎症情况。结果实验组大鼠性状改变在第3～4天最为明显,Bristol分级评分与对照组比较有显著性差异(P<0.05)。实验组大鼠在感染后第1天及第3天大便培养出致病菌,在第14天及第21天大便培养均为阴性。在感染后第21天、42天、63天测得AWR评分较对照组均明显减低(P<0.05)。组织病理学检查未见明显炎症。结论采用福氏志贺菌灌胃的方法可以成功建立感染后大鼠肠功能紊乱模型。     

大鼠感染后肠功能紊乱树突状细胞及血管活性肠态受体的变化

目的观察福氏志贺氏痢疾杆菌感染后肠功能紊乱大鼠,肠道黏膜树突状细胞(DC)表面分子CD11c与共刺激分子CD80、CD86及血管活性肠态受体(VIPR)1、2表达及意义。方法将60只雄性Wistar大鼠随机分为对照组和实验组,用福氏志贺氏痢疾杆菌灌胃造感染后肠功能紊乱模型。行大鼠回肠末端和远端结肠大体形态和组织学评分,并通过免疫组化检测肠道黏膜表面分子CD11c、CD80、CD86及VIPR1和VIPR2的表达。结果实验组大鼠与对照组相比,回肠末端和远端结肠的大体形态及组织学评分均无显著性差异(P>0.05);回肠末端CD11c、CD80及CD86阳性表达面积亦均无显著性差异(P>0.05)。而实验组大鼠远端结肠CD11c、CD80、CD86、VIPR2,以及回肠末端VIPR1、VIPR2阳性表达面积均显著高于对照组(P<0.05)。结论感染后肠功能紊乱大鼠,DC细胞可能参与远端结肠免疫激活,VIPR2对DC细胞免疫具有调节功能;回肠末端VIPR1、VIPR2在肠功能紊乱发病过程中起重要作用。     

应激在肠易激综合征发病中的作用

应激是许多疾病发生和病情加重的共同病理生理学机制，任何躯体性刺激和心理性刺激，只要达到一定程度都有可能引起应激反应。在对肠易激综合征(IBS)患者的发病机制研究中发现，从中枢神经、内分泌到免疫系统等方面，应激在IBS发病中起着重要作用。     

协同刺激分子B7与自身免疫性疾病

协同刺激分子Ｂ７与自身免疫性疾病宦红娣综述刘志红审校关键词自身免疫性疾病协同刺激分子免疫耐受中图法分类号Ｒ５９３．２自身免疫性疾病（ａｕｔｏｉｍｍｕｎｅｄｉｓｅａｓｅ）是由于机体自身免疫耐受的完整性遭到破坏所致的一组疾病，其后果取决于自身免疫耐受完整...     

应激对肠粘膜屏障功能影响的研究进展

应激状态下,各种神经、免疫、内分泌机制作用于肠上皮,导致肠粘膜屏障功能的改变,大分子抗原过多地进入固有层和粘膜下层,引发不适宜的免疫反应,进一步加剧了肠道炎症,成为慢性炎症性肠病发生和发展的重要因素。     

突触可塑性在急性束缚应激所致内脏高敏感中的作用

目的研究突触可塑性在急性束缚应激所致内脏高敏感巾的作用。方法20只雄性SD大鼠均分为对照组和急性束缚应激模型组。急性束缚应激1h诱导内脏高敏感性。观察不同结、直肠扩张压力下腹壁肌电图改变，采用10S内放电次数评估内脏高敏感性。用透射电镜技术了解结肠突触超微结构的改变，采用逆转录（RT）-PCR和Western印迹法检测回盲部、近端结肠和远端结肠突触素mRNA和蛋白质水平的表达。结果①单位时间内腹壁放电次数与直、结肠扩张压力水平呈显著正相关（对照组r=0．992，P=0．008；模型组r=0．978，P=0．022）；模型组在40、60、80mmHg（1mmHg：0．133kPa）压力下行结直、肠扩张时，腹壁肌放电次数显著多于对照组（P值分别为0．043、0．024、0．038）。②与对照组比较，模型组突触前终末聚集有较多的突触囊泡，突触后膜电子致密物质增厚。③模型组近端结肠和远端结肠突触素mRNA（P值分别为0．015、0．010）和蛋白质（P值分别为0．033、0．045）表达水平均显著增加。结论急性束缚应激所致内脏高敏感性的形成与突触可塑性有关。     

硫代乙酰胺致大鼠肠源性内毒素血症模型探讨

目的 探讨不同剂量硫代乙酰胺(TAA)所制备的大鼠肠源性内毒素血症(IETM)模型的量效关系.方法 将40只大鼠分为4组,每组10只.TAA组分别以200、400、600mg/kg剂量的TAA灌胃,24h后相同剂量TAA重复灌胃一次,建立不同剂量TAA致大鼠IETM的动物模型;健康对照组以等体积0.9%氯化钠溶液灌胃.观察造模后24、48h大鼠死亡情况,48h后采集存活大鼠腹主动脉血,检测血浆内毒素、血清ALT和AST,观察肝组织病理变化.采用单因素方差分析,组间比较采用t检验.结果 造模48h后,健康对照组无大鼠死亡,200mg/kgTAA模型组死亡2只,400mg/kg TAA模型组死亡5只,600mg/kg TAA模型组死亡8只.200、400、600mg/kg TAA模型组大鼠血清ALT水平分别为(305.09±116.78)、(901.67±274.31)和(1454.84±473.49)U/L,明显高于健康对照组的(47.81±22.61)U/L(t=14.583、25.896、20.596,均P＜0.05);200、400、600mg/kg TAA模型组大鼠血清AST水平分别为(465.88±139.96)、(884.37±250.90)和(1889.23±159.67)U/L,明显高于健康对照组的(69.33±22.04)U/L(t=12.988、18.455、13.542,均P＜0.05);200、400、600mg/kg TAA模型组大鼠血浆内毒素水平分别为(0.436±0.110)、(0.550±0.095)和(0.620±0.057)EU/mL,明显高于健康对照组的(0.103±0.056)EU/mL(t=7.335、5.260、8.191,均P＜0.05).病理学显示不同剂量TAA模型组有不同程度的肝细胞变性坏死.结论 TAA剂量为200～600mg/kg时可成功制作IETM模型,200mg/kg TAA模型组大鼠死亡率较低,适于进一步的实验研究.     

蛛网膜下腔出血致多器官功能障碍综合征大鼠模型的建立

目的通过建立蛛网膜下腔出血（SAH）致多器官功能障碍综合征（MODS）动物模型，为探讨急性脑血管病（ACVD）并发MODS的发生机制奠定基础。方法采用Willis环白体血注射法建立SAH致MODS大鼠模型。将48只Wistar大鼠随机分为正常对照组（6只）、假手术组（6只）和SAH组（分为SAH后4、12、24、36、48和72h，共6组，每组6只）。记录各时间点大鼠症状、体征，检测外周血白细胞数、肝肾功能、磷酸激酶改变。光镜下观察肺、小肠、肝和肾组织病理学变化，统计全身炎症反应综合征（SIRS）和MODS发生率。结果①假手术组大鼠呼吸、心率、体温以及外周血白细胞数、丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）、尿素氮、肌酐、磷酸激酶与正常对照组的差异均无显著性（P〉0．05）；SAH组大鼠呼吸、心率、体温及外周血白细胞数、ALT、AST、尿素氮、肌酐及磷酸激酶均高于正常对照组和假手术组（P〈0．01），并以24～36h变化最显著。②SAH组大鼠在各时间点各脏器组织均有不同程度的炎性损害，24～36h时各脏器病理学变化最显著，48h时稍有减轻，72h时仍可见炎性损害。③SAH组大鼠SIRS的发生率为100％（36／36），MODS发生率为69．4％（25／36），病死率为38．9％（14／36）。结论①Willis环白体血注射法可成功建立SAH致MODS的实验动物模型。②SAH后存在重要脏器的炎性改变和SIRS，提示SIRS是SAH致MODS的病理学基础。     

Potential rat model of anxiety-like gastric hypersensitivity induced by sequential stress

AIM To establish a rat model of anxiety-like gastric hyper-sensitivity(GHS) of functional dyspepsia(FD) induced by novel sequential stress.METHODS Animal pups were divided into two groups from postnatal day 2: controls and the sequential-stress-treated. The sequential-stress-treated group received maternal separation and acute gastric irritation early in life and restraint stress in adulthood; controls were reared undisturbed with their mothers. Rats in both groups were followed to adulthood(8 wk) at which point the anxietylike behaviors and visceromotor responses to gastric distention(20-100 mm Hg) and gastric emptying were tested. Meanwhile, alterations in several anxiety-related brain-stomach modulators including 5-hydroxytryptamine(5-HT), γ-aminobutyric acid(GABA), brain-derived neurotrophic factor(BDNF) and nesfatin-1 in the rat hippocampus, plasma and gastric fundus and the 5-HT1 A receptor(5-HT1 AR) in the hippocampal CA1 subfield and the mucosa of the gastric fundus were examined.RESULTS Sequential-stress-treated rats simultaneously demonstrated anxiety-like behaviors and GHS in dose-dependent manner compared with the control group. Although rats in both groups consumed similar amount of solid food, the rate of gastric emptying was lower in the sequentialstress-treated rats than in the control group. Sequential stress significantly decreased the levels of 5-HT(51.91 ± 1.88 vs 104.21 ± 2.88, P 0.01), GABA(2.38 ± 0.16 vs 5.01 ± 0.13, P 0.01) and BDNF(304.40 ± 10.16 vs 698.17 ± 27.91, P 0.01) in the hippocampus but increased the content of nesfatin-1(1961.38 ± 56.89 vs 1007.50 ± 33.05, P 0.01) in the same site; significantly decreased the levels of 5-HT(47.82 ± 2.29 vs 89.45 ± 2.61, P 0.01) and BDNF(257.05 ± 12.89 vs 536.71 ± 20.73, P 0.01) in the plasma but increased the content of nesfatin-1 in it(1391.75 ± 42.77 vs 737.88 ± 33.15, P 0.01); significantly decreased the levels of 5-HT(41.15 ± 1.81 vs 89.17 ± 2.31, P 0.01) and BDNF(226.49 ± 12.10 vs 551.36 ± 16.47, P 0.01) in the gastric fundus but increased the content of nesfatin-1 in the same site(1534.75 ± 38.52 vs 819.63 ± 38.04, P 0.01). The expressions of 5-HT1 AR in the hippocampal CA1 subfield and the mucosa of the gastric fundus were down-regulated measured by IHC(Optical Density value: Hippocampus 15253.50 ± 760.35 vs 21149.75 ± 834.13; gastric fundus 15865.25 ± 521.24 vs 23865.75 ± 1868.60; P 0.05, respectively) and WB(0.38 ± 0.01 vs 0.57 ± 0.03, P 0.01)(n = 8 in each group). CONCLUSION Sequential stress could induce a potential rat model of anxiety-like GHS of FD, which could be used to research the mechanisms of this intractable disease.     

Behavioral changes and mitochondrial dysfunction in a rat model of schizophrenia induced by ketamine

Evidence from the literature indicates that mitochondrial dysfunction occurs in schizophrenia and other psychiatric disorders. To produce an animal model that simulates psychotic symptoms analogous to those seen in schizophrenic patients, sub-anesthetic doses of N-methyl-D-aspartate (NMDA) receptor antagonists (such as ketamine) have been used. The aim of this study was to evaluate behavioral changes and mitochondrial dysfunction in rats administered ketamine for 7 consecutive days. Behavioral evaluation was performed using an activity monitor 1, 3 and 6 h after the last injection. The activities of mitochondrial respiratory chain complexes I, II, I-III and IV in multiple brain regions (prefrontal cortex, striatum and hippocampus) were also evaluated. Our results showed that hyperlocomotion occurred in the ketamine group 1 and 3 h after the last injection. Stereotypic movements were elevated only when animals were evaluated 1 h after receiving ketamine. In addition, we found that ketamine administration affects the respiratory chain, altering the activity of respiratory chain complexes in the striatum and hippocampus after 1 h, those in the prefrontal cortex and hippocampus after 3 h and those in the prefrontal cortex and striatum 6 h after the last administration of ketamine. These findings suggest that ketamine alters the behavior of rats and changes the activity of respiratory chain complexes in multiple brain regions at different time points.     

大鼠急性肠道损伤动物模型的建立

目的:用三硝基苯磺酸(2,4,6-trinitrobenzene sulfonic acid,TNBS)复制大鼠急性肠道损伤的动物模型.方法:SD大鼠64只随机分为制模组、制模对照组及正常对照组,分别用TNBS(乙醇稀释)、500 mL/L乙醇及生理水灌肠;观察各组大鼠制模后的粪便、精神状态、进食及存活情况;分别在第1、3、5、7及10天处死大鼠,取结肠组织,进一步观察肠道的大体病理变化和组织病理变化;再结合病理评分,总结大鼠TNBS制模后肠道病理改变的规律,评价该模型用于实验性肠道损伤研究的可行性.结果:TNBS制模组在制模后第1天即表现出明显的肠道稀便和血便,持续至实验结束;进食减少、懒动、畏寒,持续7-10 d后缓解;4只在制模后第7-9天死亡(4/34);制模后第1天即出现肠道病理改变,第5天出现急性肠道损伤,第7天病理改变最严重.制模对照组大鼠在制模后第1天部分出现稀便,持续1-2 d后消失;制模后第1天肠道出现轻度病理改变,3 d后病变减退;正常对照组大鼠未见异常,各组大鼠肠道病理评分与病变程度一致.结论:大鼠TNBS制模后早期即表现出肠道损伤,制模后第7天病理改变达到高峰,此后向慢性炎症转化:TNBS制模后5 d内可用于急性肠道损伤的实验性研究.     

急性肺损伤时大鼠肺组织connexin32 mRNA表达的变化

目的观察急性肺损伤不同时段大鼠肺组织中缝隙连接蛋白connexin32 mRNA（Cx32 mRNA）表达的变化,探讨缝隙连接与急性肺损伤发生、发展及修复的关系。方法采用油酸（0.25ml/kg）经大鼠尾静脉缓慢注入复制急性肺损伤模型,分别于注射油酸后1、5、12、24和48小时取出肺脏,用原位杂交方法评价Cx32 mRNA的表达情况。结果原位杂交显示Cx32 mRNA的表达主要定位于细胞质中。Cx32 mRNA在正常组及损伤后1、5、12、24、48小时组的平均阳性表达率分别为13.95%、5.53%、4.83%、5.27%、6.80%、8.92%。正常对照组Cx32 mRNA阳性细胞率较损伤各组高（P〈0.001）,急性肺损伤后12小时内Cx32 mRNA阳性细胞率迅速下降（P〈0.001）,损伤后第12小时到第48小时Cx32 mRNA阳性细胞率缓慢上升（P〈0.05）。结论 Cx32 mRNA表达的改变可能与急性肺损伤的发生、发展及其修复有密切的关系。     

Expression of nonclassical class I molecules by intestinal epithelial cells

It is well recognized that the nature of the immune response is different in the intestinal tract than in peripheral lymphoid organs. The immunologic tone of the gut-associated lymphoid tissue is one of suppression rather than active immunity, distinguishing pathogens from normal flora. Failure to control mucosal immune responses may lead to inflammatory diseases such as Crohn's disease (CD) and ulcerative colitis (UC) and celiac disease. It has been suggested that this normally immunosuppressed state may relate to unique antigen-presenting cells and unique T-cell populations. The intestinal epithelial cell (IEC) has been proposed to act as a nonprofessional antigen-presenting cell (APC). Previous studies have suggested that antigens presented by IECs result in the activation a CD8(+) regulatory T-cell subset in a nonclassical MHC I molecule restricted manner. We therefore analyzed the expression of nonclassical MHC I molecules by normal IECs and compared this to those expressed by inflammatory bowel disease (IBD) IECs. Normal surface IEC from the colon and, to a much lesser extent, the small bowel express nonclassical MHC I molecules on their surface. In contrast, mRNA is expressed in all intestinal epithelial cells. Surface IEC express CD1d, MICA/B, and HLA-E protein. In contrast, crypt IECs express less or no nonclassical MHC I molecules but do express mRNA for these molecules. Furthermore, the regulation of expression of distinct nonclassical class I molecules is different depending on the molecule analyzed. Interestingly, IECs derived from patients with UC fail to express any nonclassical MHC I molecules (protein and HLA-E mRNA). IECs from CD patients express HLA-E and MICA/B comparable to that seen in normal controls but fail to express CD1d. Thus, in UC there may be a failure to activate any nonclassical MHC I molecule restricted regulatory T cells that may result in unopposed active inflammatory responses. In CD only the CD1d-regulated T cells would be affected.