胆汁内引流对梗阻性黄疸大鼠胃黏膜的保护作用及机制

目的：探讨不同胆汁引流方式对梗阻性黄疸（OJ）大鼠肠黏膜的影响及机制。 方法：将80只SD大鼠随机均分为假手术组、OJ模型组（模型组）、OJ模型+胆汁内引流组（内引流组）;OJ模型+胆汁外引流组（外引流组）。实验共2周,结束时,处死各组大鼠,观察胃黏膜形态学变化,检测血清内毒素、内皮素1（ET-1）,胃黏膜ET-1、内皮素受体A（ET-A）mRNA表达。 结果：除假手术组外,各组大鼠均有不同程度的胃黏膜损伤,但内引流组的损伤情况明显较模型组与外引流组为轻;与假手术组比较,模型组和外引流组大鼠血清内毒素、ET-1和胃黏膜ET-1水平和ET-A mRNA表达明显升高,差异均有统计学意义（均P<0.05）,内引流组以上指标轻度升高,差异无统计学意义（均P>0.05）。 结论：胆汁内引流对OJ大鼠胃黏膜有保护作用,机制可能与其降低ET-1水平和ET-A的表达有关。

     

胆汁外引流对梗阻性黄疸大鼠肠黏膜紧密连接影响的实验研究

目的探讨胆汁在保护小肠黏膜屏障中的作用及其机理。方法 50只Wistar大鼠随机分为对照组(n=10)、梗阻性黄疸(阻黄)组(n=20)及外引流组(n=20)。造模10 d后测定血浆内毒素水平;取末端回肠黏膜组织,光镜下观察黏膜形态改变并测量相关指标,采用免疫组化及Western blot法检测紧密连接相关蛋白(闭锁小带蛋白-1及闭锁蛋白)的表达。结果阻黄组小肠黏膜萎缩明显,其肠绒毛高度、黏膜厚度和隐窝深度与对照组相比分别下降27.8%、21.7%和25.4%(P=0.001、0.001、0.040);外引流组各指标较对照组无明显变化(P=0.050、0.070、0.080),而明显优于阻黄组(均P=0.001)。阻黄组的血浆内毒素水平高达(1.49±0.27)EU/ml,明显高于对照组的(0.27±0.09)EU/ml(P=0.001);外引流组为(0.91±0.25)EU/ml,高于对照组而低于阻黄组(P=0.001)。免疫组化结果显示,闭锁小带蛋白-1的强阳性表达从对照组的7/10例降至阻黄组的6/20例(P=0.040),闭锁蛋白则从8/10例降至7/20例(P=0.020);而外引流组分别为8/20例(P=0.100、0.210)和9/20例(P=0.060、0.200),与前2组相比差异均没有统计学意义。Western blot分析显示,阻黄组闭锁小带蛋白-1和闭锁蛋白的表达水平较之对照组均明显下降(P=0.001、0.010);外引流组高于阻黄组(P=0.005、0.014),而闭锁小带蛋白-1的表达水平低于对照组(P=0.001),闭锁蛋白的表达与对照组比较差异无统计学意义(P=0.062)。结论肠道内胆汁缺乏会破坏肠紧密连接相关蛋白的成分,损伤肠黏膜屏障;胆道梗阻时由于存在其他因素,肠黏膜屏障损伤更严重。胆汁在保护肠黏膜屏障中具有重要作用。     

HMGB1对急性坏死性胰腺炎大鼠肠上皮细胞紧密连接相关蛋白表达的影响

目的：观察急性坏死性胰腺炎（ANP）大鼠肠黏膜中高迁移率族蛋白B1（HMG81）的表达对肠黏膜上皮细胞紧密连接功能的影响。方法：24只Wistar大鼠随机分为正常对9帚组、ANP组和丙酮酸乙酯（EP）处理组,分别于建模后24h取材。测定血浆淀粉酶（AMY）、血浆D-乳酸、肠黏膜髓过氧化物酶（MPO）水平变化;应用Westernblot法检测ANP大鼠肠黏膜中HMGBl和occludin蛋白水平的变化。结果：在建模后24h,大鼠AMY、D-乳酸与肠黏膜MPO水平ANP组明显高于正常对照组和EP处理组（P〈0．05）,但EP处理组仍高于正常对照组（P〈0．05）;ANP组大鼠肠黏膜HMGBl表达水平明显高于正常对照组和EP处理组（P〈005）,EP处理组高于正常对照组（P〈0．05）;而肠黏膜上皮细胞紧密连接蛋白occludin的表达ANP组较正常对照组和EP处理组下降（P〈0．05）,EP处理组低于正常对照组（P〈0．05）。结论：ANP大鼠肠黏膜中HMGBl表达增高,可通过降低occludin蛋白表达,增加肠黏膜屏障通透性。EP能显著抑制HMGBl表达,使occludin蛋白表达升高,对ANP肠黏膜损伤有明显保护作用。     

谷氨酰胺强化肠外营养对大鼠小肠黏膜缺血再灌注损伤的影响

目的：构建大鼠小肠缺血再灌注模型,观察谷氨酰胺强化肠外营养对小肠黏膜屏障作用的影响,并探讨其作用机制。方法：30只雌性Wistar大鼠,随机分为正常对照组（N组）、传统肠外营养组（TPN组）和谷氨酰胺强化肠外营养组（TPN＋Gln组）3组,每组10只。TPN组和TPN＋Gln组构建小肠缺血再灌注模型后予完全肠外营养5d。观察3组小肠黏膜形态、血浆D-乳酸、内毒素、TNF-α、IL-6水平及小肠黏膜HO-1 mRNA和蛋白的表达。结果：TPN＋Gln组与TPN组相比,小肠黏膜组织形态明显改善,血浆D-乳酸、内毒素、TNF-α和IL-6水平均显著性降低,HO-1 mRNA及蛋白表达水平明显增高。结论：谷氨酰胺强化肠外营养可以明显减轻大鼠缺血再灌注小肠黏膜屏障损伤及炎性反应,保护黏膜屏障完整性,并促进HO-1 mRNA表达及HO-1合成。HO-1及其代谢产物的抗氧化、抗凋亡及抗炎作用可能是谷氨酰胺保护缺血再灌注损伤小肠的作用机制。     

HMGB1 mRNA表达对急性坏死性胰腺炎大鼠肠黏膜ZO-1 mRNA及其蛋白表达的影响

目的研究高迁移率族蛋白B1（high mobility group box-1 protein,HMGB1）mRNA表达对急性坏死性胰腺炎（acute necrotizing pancreatitis,ANP）大鼠肠黏膜紧密连接蛋白-1（zonula occludens protein-1,ZO-1）表达的影响,初步探讨ANP时肠黏膜屏障损伤的可能机理。方法将96只Wistar大鼠随机（随机数字表法）均分为ANP组、丙酮酸乙酯（EP）组及假手术组,3组均分别于术后6、12、24及48 h时各抽取8只大鼠,取腹主动脉血和回肠组织。采用全自动生化分析仪检测血淀粉酶（AMY）水平,采用改良酶学分光光度法检测血浆D-乳酸水平,采用硫代巴比妥酸（TAB）比色法检测回肠组织丙二醛（MDA）含量,采用HE染色法观察大鼠回肠组织的病理学改变,采用免疫组织化学法（SP法）观察回肠组织ZO-1蛋白的表达,采用逆转录聚合酶链反应（RT-PCR）法检测回肠组织HMGB1和ZO-1 mRNA的表达。结果各时相EP组大鼠的血AMY、D-乳酸和回肠组织MDA含量均低于ANP组（P〈0.05）。6 h时,ANP组大鼠回肠组织HMGB1 mRNA的表达即上调,但ZO-1 mRNA的表达下调;各时相EP组大鼠回肠组织HMGB1 mRNA的表达水平均低于ANP组,但ZO-1 mRNA的表达水平均高于ANP组（P〈0.05）。各时相EP组大鼠回肠组织的病理学损伤均较ANP组明显减轻。结论 ANP大鼠回肠黏膜组织中ZO-1表达下调是ANP大鼠肠黏膜屏障损伤的重要原因之一,可能与炎症介质HMGB1的过度表达有关。     

TLR4表达在大鼠小肠缺血再灌注损伤中的改变及意义

目的:观察大鼠小肠缺血再灌注（I/R）损伤后小肠组织TLR4的表达及其与炎症因子水平变化的关系。方法:雄性SD大鼠90只,随机分为正常对照（N）组、假手术（S）组、小肠部分缺血/再灌注损伤（肠I/R）组。分别于缺血再灌注后6，12，24,48 h检测各组小肠组织TLR4mRNA的表达，门静脉血清中TNF-α和IL-6水平，并进行相关性分析。用免疫组化法观察TLR4在小肠组织中的表达和分布。结果:（1）肠I/R组TLR4mRNA表达上调,于I/R12 h最强,阳性细胞主要是小肠黏膜细胞;（2）I/R组门静脉血清中IL-6及TNF-α浓度与N组相比各时点均明显增高（P<0.01）;在I/R24 h后达到峰值，与S组比较差异亦有显著性 (P< 0.01);（3） 肠I/R组门静脉IL-6及TNF-α浓度的增高与小肠TLR4mRNA表达的上调呈正相关（r=0.752，r=0.812;均P<0.01）;（4）免疫组化法显示小肠黏膜细胞表面TLR4表达明显增强。结论:大鼠小肠I/R损伤后,小肠组织TLR4的表达上调可能是导致肠黏膜免疫屏障功能下降的机制之一，也可能是系统性炎症反应的始动环节。     

益生菌联合肠内营养对腹腔感染大鼠肠微生态及屏障功能的影响

目的探讨肠内肠外营养与经肠道补充益生菌对腹腔感染大鼠肠道微生态及肠屏障功能的影响。方法21只SD大鼠随机分为3组(每组7只),分别给予肠外营养(PN组)、肠外加肠内营养(PN加EN组)和肠外、肠内营养加益生菌(益生菌组)。3组营养供给为等热、等氮量。于第6天处死大鼠,取其盲肠内容物作厌氧菌培养,采用随机扩增多态性DNA技术作菌种DNA指纹图谱分析;采用免疫组织化学方法测定其末段回肠和结肠的跨膜结合蛋白及肠上皮浆细胞免疫球蛋白(IgA)表达水平;取腔静脉血及肺、肝、肠系膜淋巴组织匀浆后作细菌培养,测细菌易位率;采用鲎试剂法检测门静脉血内毒素含量。结果(1)益生菌组及PN加EN组各种菌种的数量均较PN组增多(P<0.05)。PN组细菌DNA指纹图谱条带明显减少,且出现明显异常条带,其他两组大鼠肠道内优势菌群的基因条带与正常大鼠具有较高的一致性。(2)PN加EN组和益生菌组小肠和结直肠跨膜结合蛋白及IgA表达明显高于PN组(P<0.05及P<0.01),且益生菌组跨膜结合蛋白的表达高于PN加EN组(P<0.05);PN加EN组的小肠和益生菌组结直肠IgA的表达明显高于PN组(P<0.01)。(3)PN加EN组和益生菌组血、肺、肝、肠系膜淋巴组织的细菌易位率和内毒素水平均低于PN组(P<0.05),前两组之间差异无统计学意义。结论益生菌联合EN能增加肠上皮跨膜结合蛋白IgA表达,改善肠道微生态,从而保护肠黏膜屏障、减少细菌易位。     

肠外肠内营养对腹腔感染大鼠肠上皮紧密连接和屏障功能的影响

目的　探讨肠外肠内营养对腹腔感染大鼠肠上皮紧密连接和屏障功能的影响。方法　14只存活6d的腹腔感染SD大鼠分别给予肠外营养(PN组)、肠外营养 肠内营养(PN EN组)。两组动物供给等热、等氮量。第6天处死动物,取末段回肠和结肠采用免疫组化法测定其跨膜结合蛋白(occludin)表达及肠上皮浆细胞IgA表达并定量;取腔静脉血及肺、肝、肠系膜淋巴组织匀浆后作细菌培养测细菌易位率;取门静脉血经鲎试剂法检测内毒素含量。结果　PN EN组小肠和大肠occludin及IgA表达明显优于PN组(P <0 .0 5及P <0 .0 1) ;血、肺、肝、肠系膜淋巴组织的细菌易位率和内毒素水平均低于PN组(P <0 .0 5 )。结论　肠内营养提高了肠上皮occludin表达,增加了肠道IgA的分泌,改善机械及免疫屏障,从而减少细菌易位。     

不同胆汁引流方式对梗阻性黄疸兔血清内毒素与免疫功能的影响

目的:探讨不同胆汁引流方式对梗阻性黄疸兔血清内毒素与免疫功能的影响。方法:将36只新西兰白兔随机均分为假手术组、外引流组、内引流组。外引流组与内引流组先建立可逆型梗阻性黄疸模型,7 d后解除梗阻,分别行胆汁外引流与内引流;假手术组按相同时间间隔行2次假手术。各组分别于造模前、造模后7 d、引流术后7 d采血,检测肝功能指标、血清内毒素水平、血中CD4+CD25+调节性T细胞的比例。结果:假手术组各时间点各项指标均无明显变化(均P0.05);造模后7 d,外引流组与内引流组血清胆红素、转氨酶、内毒素水平均较造模前明显升高,血CD4+CD25+调节性T细胞比例较造模前明显降低(均P0.05);行引流术7 d后,外引流组与内引流组肝功能指标、内毒素水平、CD4+CD25+调节性T细胞比例均较造模后7 d明显恢复,但内引流组后两项指标的恢复程度均明显优于外引流组(均P0.05)。结论:胆汁内引流较胆汁外引流更有利于梗阻性黄疸内毒素清除与机体免疫功能快速恢复。     

不同营养方式对梗阻性黄疸大鼠肠紧密连接蛋白的影响

目的 观察肠内营养(EN)及肠外营养(PN)对阻塞性黄疸(OJ)大鼠小肠紧密连接蛋白的影响.方法 将50只Wistar大鼠随机分5组,EN组和PN组给予等热量等氮量营养.7 d后采用免疫组织化学和Western blot法检测各组末端回肠黏膜的闭锁小带-1(ZO-1)、闭锁蛋白(Occludin)与肌球蛋白轻链激酶(MLCK)的表达,并对Western blot图像进行定量分析.结果 正常回肠黏膜ZO-1和Occludin沿绒毛下方均匀连续分布,MLCK主要分布在细胞质内.阻黄时ZO-1、Occludin和MLCK分布散乱,染色稀疏.PN组的ZO-1、Occludin和MLCK的强阳性染色数由阻黄组的2、2、1例升至4、5、3例(P均>0.05),而EN组的强阳性染色数分别上升为7、6、5例(P均<0.05).通过对Western blot显影图像进行定量分析,EN组和PN组的ZO-1的灰度值较阻塞性黄疸组明显上升(均P<0.05);Occludin和MLCK的灰度值在EN组上升(P<0.05),PN组没有变化.结论 梗阻性黄疸时大鼠小肠黏膜上皮ZO-1、Occludin和MLCK分布紊乱,表达下降.肠内、外营养均能够恢复受损的紧密连接蛋白,肠内营养的作用更强.     

梗阻性黄疸时脾切除对肠黏膜屏障影响的实验研究

目的 探讨脾脏在梗阻性黄疸(阻黄)中对肠黏膜屏障的作用及其机制.方法 50只Wistar大鼠随机分组,阻黄组开腹结扎胆总管;阻黄+脾切除组,同时切除脾脏.术后7d观察血浆内毒素水平的变化,用乳果糖/甘露醇(L/M)比值检测肠黏膜通透性;采用免疫组织化学、Western印迹检测末端回肠紧密连接蛋白闭锁小带-1(ZO-1)、闭锁蛋白的表达,并利用图像分析系统对Western印迹图像进行定量分析.结果 阻黄+脾切除后L/M的比值和血浆内毒素水平较阻黄组明显下降(均P=0.001).与阻黄组相比,阻黄+脾切除组的平均肠绒毛高度和隐窝深度有所上升(P=0.019、0.001).免疫组化显示术后7 d阻黄组ZO-1蛋白强阳性表达数(6/18)下降明显(P=0.021),阻黄+脾切除组(8/17)染色较阻黄组变化不大;闭锁蛋白的染色阻黄+脾切除组强阳性表达(7/17)高于阻黄组(4/18)(P=0.026).通过对Western印迹图像进行定量分析也得出同样的结论.结论 阻黄后肠黏膜通透性增加,肠黏膜屏障受损.同时切除脾脏,肠紧密连接蛋白成分的数量和分布改变,肠黏膜屏障的损害减轻.

Abstract：

Objective To investigate the effects of splenectomy on the intestine mucosa barrier in rats with obstructive jaundice. Methods 50 Wistar rats were divided randomly into the obstructive jaundice group (OJ), in which the animals underwent operation to ligate common bile duct, and the obstructive jaundice + splenectomy group (OJ+ S). Seven days post-operation, plasma endotoxin levels were detected. Intestinal mucosa permeability was measured by the ratios of lactulose and mannitol (L/M). Immunohistochemistry and Western blot were used to examine the expression of tight junction proteins (ZO-1 and occludin) in the distal ileum mucosa. Western blots images were analyzed quantitatively. Results Average ratios of L/M and plasma endotoxin were decreased obviously in the OJ+S group compared to those in the OJ group (all P=0. 001). Compared with the OJ group, the average intestinal villus height and mucosa thickness were upgraded somewhat in the OJ + S group (P = 0.019, 0. 001 ). By immunohistochemistry staining seven days post-operation, same comment as above the amounts of strong positive expression of ZO-1 were significantly decreased in the OJ group (6/18, P-0. 021). There wewas no difference between the OJ+S group(8/17) and the OJ group.The amount of strong positive expression of occludin was higher in the OJ + S group than that of the OJ group(10/17 vs 4/18, P= 0. 026). The same outcomes were obtained by quantitative Western blot images. Conclusion The intestinal epithelial permeability was increased in rats with obstructive jaundice,and intestinal barrier was damaged. After excising spleen, the amount and distribution of tight junction proteins were changed and the impairment of intestinal barrier was abated.     

梗阻性黄疸时脾切除对肠黏膜屏障影响的实验研究

目的 探讨脾脏在梗阻性黄疸(阻黄)中对肠黏膜屏障的作用及其机制.方法 50只Wistar大鼠随机分组,阻黄组开腹结扎胆总管;阻黄+脾切除组,同时切除脾脏.术后7d观察血浆内毒素水平的变化,用乳果糖/甘露醇(L/M)比值检测肠黏膜通透性;采用免疫组织化学、Western印迹检测末端回肠紧密连接蛋白闭锁小带-1(ZO-1)、闭锁蛋白的表达,并利用图像分析系统对Western印迹图像进行定量分析.结果 阻黄+脾切除后L/M的比值和血浆内毒素水平较阻黄组明显下降(均P=0.001).与阻黄组相比,阻黄+脾切除组的平均肠绒毛高度和隐窝深度有所上升(P=0.019、0.001).免疫组化显示术后7 d阻黄组ZO-1蛋白强阳性表达数(6/18)下降明显(P=0.021),阻黄+脾切除组(8/17)染色较阻黄组变化不大;闭锁蛋白的染色阻黄+脾切除组强阳性表达(7/17)高于阻黄组(4/18)(P=0.026).通过对Western印迹图像进行定量分析也得出同样的结论.结论 阻黄后肠黏膜通透性增加,肠黏膜屏障受损.同时切除脾脏,肠紧密连接蛋白成分的数量和分布改变,肠黏膜屏障的损害减轻.     

Reversibility of leukocyte dysfunction in rats with obstructive jaundice

BACKGROUND: The role of leukocytes in obstructive jaundice is obscure and the effect of relieving cholestasis on leukocyte function is unclear. We postulated that cholestasis affects systemic polymorphonuclear leukocyte function by deranging phagocytosis and hydrogen peroxide release and the leukocyte dysfunction is reversible by internal and external biliary drainage. MATERIALS AND METHODS: Sixty male Sprague Dawley rats were randomly assigned to four groups: obstructive jaundice (OJ), sham operation (SH), OJ with internal drainage (ID), and OJ with external drainage (ED). The phagocytic functions of neutrophils and monocytes in whole blood were measured with flow cytometry using fluorescent microspheres. Intracellular hydrogen peroxide production by leukocytes was assessed with flow cytometry using dihydrorhodamine-123 as probes. RESULTS: Leukocyte count and percentage of monocytes in rats with OJ was significantly increased compared with SH rats (P < 0.001). These elevations could be reversed by both ID and ED method (P < 0.001). The phagocytic function of neutrophils and monocytes was significantly depressed in OJ rats compared with that in SH rats (P < 0.001). After relief of the OJ, the suppressed phagocytic function of neutrophils and monocytes was completely improved in ID rats (ID versus OJ, P < 0.001), but only partially reversed in ED rats. The hydrogen peroxide production by monocytes and lymphocytes was significantly increased in OJ rats (P < 0.05). ID reversed the increased hydrogen peroxide generation (P < 0.05), but ED only partially did. CONCLUSIONS: In our rodent model of biliary obstruction, deranged phagocytosis, and hydrogen peroxide generation by leukocytes was found. Internal drainage is superior to external drainage for reversal of the distorted leukocyte function.     

GLP-2对实验性梗阻性黄疸小肠上皮细胞紧密连接的调控

目的:探讨类高血糖素多肽-2（GLP-2）对实验性梗阻性黄疸小肠上皮细胞紧密连接的调控。方法:建立梗阻性黄疸大鼠模型，造模后10d随机分组，每组10只。黄疸组皮下注射0.01 mmol/LPBS 0.5 mL，实验甲组腹腔注射250 g/（kg·d），实验乙组腹腔注射125g/（kg·d）的GLP-2溶液0.5 mL，每天2次，连续7 d后处死。另设正常对照组，用免疫组化及Western blots检测末端回肠黏膜紧密连接蛋白ZO-1,Occludin及Claudin-1, Claudin-4的分布和表达，并用图像分析系统对Western blots图像进行定量分析。结果:正常情况下ZO-1,Occludin和Claudin-1染色强阳性率分别为70.0%,80.0%和70.0%。梗阻性黄疸时ZO-1和Occludin分布不均，染色变淡，线条模糊。补充外源性GLP-2后，实验甲组的ZO-1,Occludin和Claudin-1染色有所恢复，且强阳性表达率分别从黄疸组的20.0%，30.0%和20.0%升至实验甲组的80.0%,90.0%和80.0% (均P<0.05)；Claudin-4表达和分布变化不明显。实验乙组对紧密连接蛋白无影响。Western blots图像定量分析得到相同的结果。 结论:梗阻性黄疸时，补充GLP-2可影响小肠黏膜上皮紧密连接蛋白的分布和表达；提示GLP-2能恢复和维持小肠黏膜上皮屏障的完整性。     

bFGF ameliorates intestinal mucosal permeability and barrier function through tight junction proteins in burn injury rats

BackgroudTo investigate the protective effect of exogenous basic fibroblast growth factor (bFGF) treatment on the intestinal mucosa in scalded rats.MethodsThirty-six SD rats were randomly divided into 3 groups (n = 12): sham group, scald group and bFGF group (0.5 mg/kg). Intestinal barrier dysfunction was evaluated by permeability of intestinal mucosa to fluorescein isothiocyanate (FITC)-dextran and Chiu’s grading system. H&E staining was used to detect the morphological changes of intestinal mucosa. Immunohistochemistry was used to observe zonula occludens-1 (ZO-1) and occludin. Western blot assay was used to detect the expression of ZO-1, Claudin-1, occludin and myosin light-chain kinase (MLCK).ResultsThe results demonstrated that following bFGF treatment, permeability of the intestinal epithelium barrier of was significantly decreased compared to scald group. H&E staining and Chiu’s grading were consistent with previous result. The expression of ZO-1, Claudin-1, occludin in bFGF group were significantly increased compared to scald group, while MLCK protein was decreased.ConclusionsbFGF ameliorates permeability of intestinal mucosa after burns. The possible mechanism may be relate to bFGF could increase the expression level of tight junction proteins (TJPs).     

梗阻性黄疸大鼠肠黏膜上皮紧密连接蛋白和MLCK的研究

目的:探讨梗阻性黄疸肠黏膜屏障破坏的机制。方法:建立梗阻性黄疸大鼠的动物模型,分别于胆管结扎10 d和20 d后，采用免疫组化、Western blot方法检测末端回肠黏膜的紧密连接蛋白成员ZO-1和Occludin与肌球蛋白轻链激酶（MLCK）的分布和表达。结果:正常回肠黏膜层ZO-1和Occludin的分布相似，主要位于上皮细胞的边缘，细胞膜顶端，沿绒毛下方均匀连续分布；MLCK主要分布在细胞浆内。梗阻性黄疸时ZO-1和Occludin分布不均, 染色变淡，线条模糊，边缘粗糙有毛刺状突起；MLCK分布散乱，染色稀疏。与对照组相比20 d组和10 d组的ZO-1，Occludin，MLCK数量明显减少，强阳性表达率分别从70.0 %，80.0 %，70.0 %降至10 d组的28.6 %，28.6 %，28.6 % (均P＜0.05)和20 d组的ZO-1从10 d 组的28.6 %降至14.3 %, 35.7 %, 21.4 % (均P＜0.05)。20 d 组的ZO-1下降较10 d组更为明显（P<0.05）, 而Occludin和MLCK变化不明显。Western blot检测的结果与之相似。结论:梗阻性黄疸时大鼠小肠黏膜上皮ZO-1，Occludin，MLCK分布紊乱，表达下降，小肠黏膜上皮屏障的完整性破坏。     

Internal biliary drainage improves decreased number of gut mucosal T lymphocytes and MAdCAM-1 expression in jaundiced rats

BACKGROUND: Although the effect of preoperative biliary drainage in patients with obstructive jaundice is controversial, bacterial or endotoxin translocation is one of the main postoperative problem in jaundiced patients. Failure in gut barrier functions causes bacterial translocation; homing and distribution of T lymphocytes in the intestinal lamina propria are important for gut mucosal immune defense. This study was performed to examine whether bile regulates the numbers of T lymphocyte subsets or the expression of mucosal addressin cell adhesion molecule-1 (MAdCAM-1) in experimental jaundice in rats with and without external and internal biliary drainage. METHODS: Four groups of Wistar rats were used: those that received a sham operation (SHAM), common bile duct ligation (CBDL), CBDL followed by external drainage (ED), and CBDL followed by internal drainage (ID). Numbers of CD4(+) and CD8(+) T lymphocytes and MAdCAM-1-positive cells in the lamina propria were counted immunohistochemically in the specimens of jejunum and ileum of each group. Bacterial translocation was examined by culturing from the mesenteric lymph node complex isolated from rats in each group. RESULTS: A significant decrease in numbers of CD4(+) and CD8(+) T lymphocytes and MAdCAM-1-positive cells in the lamina propria was seen in obstructive jaundice, although numbers of peripheral blood lymphocytes increased in comparison with the sham-operated control. The numbers of CD4(+) and CD8(+) T lymphocytes and MAdCAM-1 expression in the lamina propria did not recover to a normal level after external drainage, but did so after internal drainage. Frequencies of bacterial translocation were high in the CBDL and ED group. In contrast, bacterial translocation was not present in any animals in the SHAM group and was at a low percentage in the ID group. CONCLUSIONS: Changes in the number of T lymphocytes and MAdCAM-1 expression are associated with the presence of bile in the gastrointestinal tract and are inversely correlated with the frequency of bacterial translocation induced by CBD ligation. MAdCAM-1 expression maintained by the presence of bile may regulate T-lymphocyte homing to the lamina propria in obstructive jaundice.