Tempo对肝硬化大鼠肝组织缺血再灌注后肝功能的保护作用及机制

目的探讨4-羟基-2.2.6.6-四甲基哌啶（Tempo）对肝硬化大鼠肝组织缺血再灌注后肝功能的保护作用。方法取90只SD成年大鼠采用传统四氯化碳（CCL4）法制作肝硬化模型并随机分为假手术组、模型组及治疗组各30只。模型组及治疗组行开腹肝门阻断术（假手术组只暴露肝门,不阻断）,肝门阻断后30 min恢复血流。治疗组术前缓慢静脉注射TEMPO 10 mg/100 g（用生理盐水稀释10倍）,术后每12 h静注1次;模型组及假手术组术前均缓慢静脉注射与治疗组所用药物等体积的生理盐水,术后每12 h静注1次。术后72 h观察两组肝组织病理学变化、细胞凋亡情况;测定肝组织上清液超氧化物歧化酶（SOD）、过氧化物酶（CAT）、谷胱甘肽过氧化物酶（GSH-Px）活性及丙二醛（MDA）水平;测定三组肝功能指标。结果治疗组肝组织上清液中SOD、CAT、GSH-Px活性明显高于模型组（P〈0.05）,MDA水平明显低于模型组（P〈0.05）;ALT、AST及LDH水平明显低于模型组（P〈0.05）。结论 TEMPO对肝硬化缺血再灌注损伤大鼠的肝功能有保护作用。     

大承气汤对急性肝损伤大鼠肠源性内毒素血症生物学效应的阻断作用

目的：观察大承气汤对急性肝损伤大鼠肠源性内毒素血症生物学效应的阻断机制及作用。方法：取Wistar大鼠30只随机分为3组，正常对照组（A组），大承气汤治疗组（B组），急性肝损伤模型组（C组），每组各10只。B、C两组大鼠均以皮下注射硫代乙酰胺（TAA）600mg／kg造模。A组大鼠给予生理盐水灌胃。B组大鼠于造模前2走开始以大承气汤灌胃，直至造模成功后3天。处死大鼠取肝脏行病理学检测厦免疫组化检测，并测定血浆内毒素和肿瘤坏死因子（TNF-α）、血清ALT、TBil水平。结果：与A组相比，C组大鼠血浆内毒素、THF-α、血清ATL、TBil明显升高（P〈0.05）。经大承气汤治疗后，其血浆内毒素、TNF-α、血清ALT、TBil明显降低（P〈0．05）。肝脏病理检测结果显示，C组大鼠肝细胞呈弥漫性大片状坏死，肝窦结构被破坏，汇管区可见大量炎症细胞浸润，B组大鼠肝脏病理改变明显减轻。免疫组化结果显示，C组大鼠肝组织可见核因子-κB及CD14明显活化。与C组相比。B组核因子-κB及CDl4活化明显减弱。结论：急性肝损伤大鼠肝组织中核因子-κB及CD14活化明显，大承气汤对急性肝损伤大鼠肠源性内毒素血症生物学效应具有阻断作用。     

梗阻性黄疸对大鼠周围神经结构的影响

将30只Wistar大鼠随机分为对照组、假手术组、梗阻性黄疸（OJ）组,每组10只。OJ组大鼠于近肝门处游离并结扎胆总管,假手术组仅做游离但不结扎胆总管。对照组、假手术组大鼠术后体质量上升,OJ组体质量显著降低,与术前相比P均〈0.05。OJ组大鼠术后血清直接胆红素、胆汁酸、内毒素水平显著高于正常对照组和假手术组,P均〈0.01。OJ组神经损伤较重。认为梗阻性黄疸大鼠存在周围神经变性,与内毒素移位和高胆红素血症有关。     

急性肝损伤大鼠肠源性内毒素血症形成机理及其作用的实验研究

探讨急性肝损伤大鼠肠源性内毒素血症的形成机理及肠源性内毒素血症在急性肝损伤过程中的作用.采用皮下注射硫代乙酰胺（TAA）600 mg/kg制作大鼠急性肝损伤动物模型,取回肠内容物、肝、脾、淋巴结作细菌培养,检测血浆及回肠内容物内毒素含量.行血浆D-乳酸的检测.取肝脏和回肠作病理切片.结果显示TAA诱导大鼠急性肝损伤后,血浆及回肠内容物内毒素水平上升明显（P＜0.01）,血浆TNF-α含量升高明显（P＜0.01）,且与内毒素水平升高呈正相关（P＜0.01）.同时出现肠道菌群失调,肠道通透性增加,肠道细菌移位.回肠病理所示肠绒毛明显变短、破坏、炎性细胞浸润增多.因此肠道菌群失调、肠粘膜结构改变、肠道通透性增加及肠道细菌移位是形成肠源性内毒素血症的重要因素.内毒素可直接或通过诱导TNF-α加重肝损伤.     

肝硬化大鼠模型肠壁结构及细菌移位的研究

目的 研究肝硬化大鼠模型肠黏膜结构的改变及细菌移位.方法 采用皮下注射40%四氯化碳诱导大鼠肝硬化模型,比较肝硬化大鼠模型与正常对照组小肠组织结构及超微结构的变化;将肝、脾和肠系膜淋巴结组织匀浆进行细菌培养,了解肠道细菌移位情况;采用鲎实验检测血浆内毒素水平.结果 与正常对照组相比,肝硬化模型组小肠绒毛表面积显著下降(P<0.01),而肠隐窝深度无明显变化(P>0.05),肠黏膜上皮细胞微绒毛明显缩短、稀疏,上皮细胞间紧密连接结构模糊,细胞间隙增大;肝硬化模型组肝、脾、肠系膜淋巴结细菌移位发生率分别为16.67%、16.67%和41.67%,正常对照组未发现细菌生长;肝硬化模型组血浆内毒素水平明显高于正常对照组(P<0.01).结论 肝硬化大鼠模型肠黏膜上皮组织及超微结构发生改变,从而导致肠道细菌移位和血浆内毒素水平的升高.     

D-氨基半乳糖大鼠急性肝衰竭并发内毒素血症对糖代谢的影响及其机制

目的：探讨大鼠急性肝功能衰竭时内毒素血症对糖代谢的影响及其机制。方法：利用D-氨基半乳糖（D—GaLN）诱导建立大鼠肝衰竭模型,24只雄性Wistar大鼠随机分为对照组（等渗盐水）、低剂量组（100mg／kgD—GaLN）、中剂量组（200mg／kgD—GaLN）、高剂量组（300rag／kgD—GaLN）,收集各组血清和肝组织,检测内毒素、血糖、肝功能,采用半定量PCR方法检测大鼠肝组织中葡萄糖-6-磷酸酶（G6P）和磷酸烯醇丙酮酸羧激酶（PEPCK）的基因转录,6-磷酸葡萄糖法检测葡萄糖激酶（GCK）活性。结果：200mg／kg以上剂量D—GaIN可诱导大鼠急性肝衰竭,并出现低糖血症,内毒素水平随着D—GaIN浓度升高而升高;实验组大鼠GCK活性较对照组均升高,而G6P、PEPCK的mRNA表达随D—GaIN浓度升高而下调。结论：急性肝功能衰竭大鼠并发内毒素血症可能通过促进糖酵解、抑制糖异生导致低血糖的发生。     

内毒素血症在大鼠实验性肝硬化腹水形成中的作用及其与肿瘤坏死因子-α和一氧化氮的关系

背景：肝硬化失代偿期时多伴有内毒素血症，内毒素血症是造成和（或）加重肝硬化进展的重要因素之一。目的：研究内毒素血症在大鼠实验性肝硬化腹水形成中的作用，探讨血清内毒素血症与血清肿瘤坏死因子（TNF）-α和一氧化氮（NO）间的关系。方法：采用CCl4方法建立肝硬化大鼠模型，以鲎试剂偶氮显色法、酶联免疫吸附试验（ELISA）双抗体夹心法和比色法分别测定正常对照组（n=10）、肝硬化组（n=15）和肝硬化伴腹水组（n=18）大鼠腹主动脉血中内毒素、TNF-α和NO的水平。结果：肝硬化组和肝硬化伴腹水组大鼠血清内毒素、TNF-α和NO水平均显著高于正常对照组：多元回归分析表明．肝硬化组和肝硬化伴腹水组大鼠血清内毒素水平与血清TNF-α和NO水平呈显著正相关：肝硬化伴腹水组大鼠的腹水量与血清TNF-α和NO水平呈显著正相关。结论：肝硬化腹水的形成与内毒素血症逐渐加重有关，内毒素增加诱导了TNF-α和NO的过度分泌。     

肝肺综合征大鼠血细胞因子和肺血管巨噬细胞观察

目的：观察肝肺综合征大鼠肺组织中肺血管巨噬细胞浸润情况和血浆内毒素水平。方法取 Wistar大鼠30只,随机分为假手术组和胆总管结扎肝纤维化模型组（CBDL 组）,于造模5 w 末处死动物,收集血清及肝肺组织;分别检测血气、内毒素（鲎试验）、一氧化氮（硝酸还原酶法）、肿瘤坏死因子-α（ELISA 法）,观察肝、肺组织病理学变化及肺组织肺血管内巨噬细胞的浸润情况。结果在 CBDL 组动物,5 w 时血气分析示 PaO2为（64.2±7.3） mmHg,显著低于假手术组[（97.7±4.5）mmHg,P〈0.05）];CBDL 组5 w 时血浆内毒素、一氧化氮和肿瘤坏死因子-α分别为（0.2297±0.0362）Eu/ml、（56.2±9.5）μmol/L 和（1.5±0.2）ng/ml,均明显高于假手术组[（0.0938±0.0309） Eu/ml、（32.9±4.3）μmol/L 和（1.5±0.2）ng/ml,P〈0.05）];病理学检查示5 w 时模型组大鼠肝组织可见纤维化表现,肺组织中肺毛细血管扩张、充血,有肺血管巨噬细胞存在。结论在胆总管结扎法诱导的大鼠肝硬化模型中,血清内毒素水平升高、肺血管巨噬细胞浸润和炎性细胞因子分泌增加,可能是肺血管扩张、低氧血症及肝肺综合征发生的重要机制。     

促肠动力药对肝硬化肠源性内毒素血症的影响

目的：评价促肠动力药对肝硬化肠源性内毒素血症的治疗价值。方法：肝硬化大鼠分为促肠动力药治疗组和对照组,治疗前后分别采血测内毒素水平,另设正常对照组。52例肝硬化病人分成促肠动力药组（A组）,乳果糖组（B组）和对照组（C组）,疗程2周,治疗前后分别抽血测内毒素,结果：治疗前两组肝硬化大鼠的血清内毒素水平无差别（P＞0．05）,高于正常大鼠（P＜0．01）,经促肠动力药物治疗后内毒素明显降低（P＜0．01）,治疗肝肝硬化病人内毒素水平在A、B组均有下降（P＜0．01）,两组间差异无统计学意义;对照组前后两次血内毒素水平无明显差异。结论：促肠动力药能降低肝硬化大鼠和病人的血清内毒素水平,提示其对肝硬化肠源性内毒素血症的治疗有益。     

炎症介质和细胞因子在急性脑缺血模型大鼠肠道细菌移位中的作用

目的探讨急性脑缺血模型大鼠肠黏膜屏障应激性损害发生的机制。方法 64只雄性W istar大鼠随机分为缺血模型组和假手术对照组,两组大鼠分别按术后6、12、24和48 h时相点分为4个亚组（每组8只）。测定门静脉血内毒素（ET）、肿瘤坏死因子α（TNF-α）以及肠黏膜组织一氧化氮（NO）水平,检测肠系膜淋巴结等多器官组织匀浆中标记大肠杆菌的移位率。结果各时相点门静脉血ET、TNF-α以及肠黏膜组织NO水平模型组较对照组升高,P均〈0.05;多脏器荧光标记大肠杆菌检出率模型组高于对照组,P〈0.05。结论急性脑缺血模型大鼠伤后早期即有肠道细菌移位,与炎症介质和细胞因子水平的升高密切相关,是肠黏膜屏障损害的重要因素。     

乳果糖对肝癌切除术后血浆内毒素血症及肝损伤的防护作用

目的：探讨乳果糖对肝脏缺血再灌注后内毒素血症所致肝损伤的防护作用。方法：40例肝癌患者随机分为乳果糖组及对照组。测定两组肝癌手术患者肝门阻断前后门静脉血、外周静脉血内毒素以及术前、术后第1、3、7天肝功能检测结果,做统计学分析。结果：肝门阻断前,乳果糖组患者内毒素水平要低于对照组（t=27．60,P〈0．01）：肝门阻断后,两组患者内毒素水平均升高,但对照组更高,差异有极显著意义（t=12．72,P〈0．01）,说明乳果糖可以明显减轻内毒素血症。术前两组患者血中丙氨酸转氨酶（ALT）和天门冬氨酸转氨酶（AST）均高于正常参考值,但乳果糖组较对照组略低,差异有统计学意义（t=4．28,P〈0．01;t’=4．91,P〈0．05）,术后第3天两组患者ALT和AST升高的水平最高,两组问差异有统计学意义（t’=2．11,P〈0．05）。结论：肝切除术前患者口服乳果糖,能降低其肝缺血后血中内毒素水平,减轻肝脏的缺血再灌注损伤,改善肝脏功能,有利于术后肝功能的恢复,对于预防术后急性肝功能衰竭起一定作用。     

Hyperbaric oxygen ameliorates bacterial translocation in rats with mechanical intestinal obstruction

PURPOSE: The aim of this study was to demonstrate bacterial translocation after experimentally induced intestinal obstruction as well as investigate the preventive effects of hyperbaric oxygen on obstruction-induced bacterial translocation in rats. METHODS: Forty Wistar-albino male and female rats were used. Although no procedure was done in the control group (n = 8), hyperbaric oxygen treatment under 2.5 atm absolute for 90 minutes daily was applied for two days in the hyperbaric oxygen group (n = 8). In the sham group (n = 8), after laparotomy the small bowel was only handled gently, and tissue sampling was done 48 hours later. In the obstruction group (n = 8) the ileum was ligated by 5-0 polypropylene just 5 cm proximal to the ileocecal valve. In the obstruction and hyperbaric oxygen group (n = 8), after obstruction hyperbaric oxygen treatment was applied. Forty-eight hours after the procedures, tissue samples from small bowel, mesenteric lymph nodes, spleen, and liver were taken and 1 ml of blood from the portal vein was withdrawn. All samples were cultured for microbiologic examination. RESULTS: Hyperbaric oxygen treatment significantly reduced the endogenous bacterial overgrowth in the small intestine of normal rats. Endogenous bacteria in the small intestine were significantly increased in the obstruction group, and the presence of bacterial overgrowth was proven by bacterial presence on mesenteric lymph nodes, spleen, liver, and blood. Hyperbaric oxygen treatment significantly reduced the endogenous bacterial overgrowth in the small intestine and prevented the bacterial translocation almost completely in obstruction-induced rats. CONCLUSIONS: Intestinal obstruction causes bacterial overgrowth and translocation. Hyperbaric oxygen treatment prevents the bacterial translocation effectively.     

谷氨酰胺对急性胰腺炎大鼠肠黏膜胰岛素样生长因子表达及肠黏膜屏障的影响

目的 观察急性坏死性胰腺炎（ANP）时肠黏膜屏障的损伤情况,以及谷氨酰胺（Gln）和胰岛素样生长因子（IGF）对肠黏膜屏障的保护作用.方法 成功诱导ANP模型雄性Wistar大鼠48只,随机分为ANP组和Gln组各24只,另取假手术组24只作为对照.Gln组每日以Gln灌胃2次,剂量为1.5g/（kg·d）;ANP组和假手术组以同等量的生理盐水灌胃.分别在模型制作术后3、6、24、48 h时间点杀死大鼠,取胰头和末端回肠3～5 cm放入液氮中保存.观察胰腺和肠黏膜组织形态学改变,测定肠黏膜中IGF-1的表达、血清中二氨氧化酶（DAO）活性和内毒素浓度.结果 ANP组大鼠肠黏膜屏障功能严重破坏,肠道通透性明显增加,肠黏膜损伤评分明显增加;血清内毒素浓度、DAO活性明显升高（P均＜0.01）.与ANP组比较,Gln组动物肠黏膜损伤减轻,损伤评分有所下降,血清内毒素水平、DAO活性下降（P均＜0.05）.ANP组IGF-1表达水平明显下降（P ＜0.05）;Gln组明显升高（P＜0.05）,同时肠黏膜屏障功能得到一定的改善.结论 ANP时肠黏膜屏障结构和功能存在严重破坏;Gln能一定程度上减轻肠黏膜屏障损伤并能维护其功能;IGF-1参与Gln对ANP肠黏膜屏障损伤的修复和维持.     

Effect of acute portal hypertension on gut mucosa

BACKGROUND/AIMS: Patients with cirrhosis are predisposed to develop spontaneous bacteremias and peritonitis, mainly by enteric bacteria. Portal hypertension, by producing congestion and edema of the bowel wall, could increase the passage of bacteria from the intestinal lumen to regional lymph nodes to the systemic circulation or to both, a process termed bacterial translocation. The aim of this study was to investigate bacterial translocation, brush border enzyme activity and intestinal permeability of experimental acute portal hypertension. METHODOLOGY: Twenty-six male Wistar rats were used for all experiments. Rats were studied two days after the induction of portal hypertension (n = 13). Control animals were also studied two days after sham operation (n = 13). Samples of mesenteric lymph nodes for standard bacteriological cultures and a fragment of ileum for histological examination and mucosal contents of protein, Alp were obtained. Moreover, we evaluated the intestinal permeability by using the phenolsulfonphthalein test. RESULTS: Two days after surgery, a significantly greater properties of rats with acute portal hypertension (12 of 13, 92%) had positive mesenteric lymph node cultures compared with control group: sham operated (2 of 13, 15%). A significant increase in disappearance of phenol red from the luminal solution was observed in rats with acute portal hypertension. Brush border enzyme of Alp was also significantly decreased in acute portal hypertension, compared with in sham operated controls. CONCLUSIONS: The results of our study suggested that acute portal hypertension may be a major factor in the development of spontaneous infections in cirrhosis.     

Outcome in adulthood of biliary atresia: a study of 63 patients who survived for over 20 years with their native liver

To define the long-term prognosis of children undergoing the Kasai operation for biliary atresia, a retrospective study was undertaken comprising 271 patients operated between 1968 and 1983. Twenty years after surgery, 63 (23%) were alive with their native liver. Serum bilirubin was normal in 21 of these patients, 12 also had normal serum aminotransferase and gamma-glutamyltransferase activities, all but 2 had signs of cirrhosis, 44 had signs of portal hypertension, 19 had late bacterial cholangitis, and 6 had gallstones. Seven female patients gave birth to 9 children, and 3 male patients fathered 6 children. After age 20, 2 patients died of liver failure and 14 underwent or are awaiting liver transplantation. Twenty-year survival with native liver was significantly better in children with biliary atresia restricted to the hepatic ducts or with cysts at the porta hepatis. In conclusion, in the long term, less than 18% of infants with biliary atresia who are treated with corrective surgery may avoid liver transplantation, but even these patients require assiduous lifelong care.     

温阳解毒化瘀颗粒对肠源性内毒素血症大鼠肠黏膜上皮紧密连接的影响

目的：研究温阳解毒化瘀颗粒对肠源性内毒素血症（ IETM ）模型大鼠结肠黏膜上皮紧密连接的影响,探索其抗肝衰竭的作用机制。方法：将大鼠随机分为正常组、模型组、温阳解毒化瘀颗粒（实验组）和对照组4组,采用D-半乳糖胺（D-gal）腹腔注射致肝衰竭ITEM大鼠模型。正常组在腹腔注射生理盐水24h后处死,模型组、实验组、对照组分别于造模后24h、48h、72h各取6只、7只、7只大鼠处死,检测各组肝功能、内毒素、结肠黏膜上皮咬合蛋白（occludin）及肌球蛋白轻链激酶（MLCK）。结果：模型组血清ALT/AST、内毒素、 MLCK表达水平均高于正常组, occludin表达低于模型组（ P＜0.01）;实验组血清ALT/AST、内毒素、 MLCK表达水平均低于模型组, occlu-din表达高于模型组（ P＜0.05）。结论：增强结肠粘膜上皮紧密连接功能,降低内毒素的吸收是温阳解毒化瘀颗粒抗肝衰竭的作用机制之一。     

Insulin-like growth factor I improves intestinal barrier function in cirrhotic rats

BACKGROUND AND AIMS: In liver cirrhosis, disruption of the intestinal barrier facilitates bacterial translocation and spontaneous bacterial peritonitis. Insulin-like growth factor I (IGF-I) is an anabolic hormone synthesised by hepatocytes that displays hepatoprotective activities and trophic effects on the intestine. The aim of this study was to investigate the effect of IGF-I on intestinal barrier function in cirrhotic rats. METHODS: In rats with carbon tetrachloride induced cirrhosis, we investigated the effect of IGF-I therapy on: (a) portal pressure; (b) intestinal histology and permeability to endotoxin and bacteria; (c) intestinal expression of cyclooxygenase 2 (COX-2) and tumour necrosis factor alpha (TNF-alpha), two factors that influence in a positive and negative manner, respectively, the integrity of the intestinal barrier; (d) intestinal permeability to 3H-mannitol in rats with bile duct ligation (BDL); and (e) transepithelial electrical resistance (TER) of polarised monolayers of rat small intestine epithelial cells. RESULTS: IGF-I therapy reduced liver collagen expression and portal pressure in cirrhotic rats, induced improvement in intestinal histology, and caused a reduction in bacterial translocation and endotoxaemia. These changes were associated with diminished TNF-alpha expression and elevated COX-2 levels in the intestine. IGF-I reduced intestinal permeability in BDL rats and enhanced barrier function of the monolayers of epithelial intestinal cells where lipopolysaccharide (LPS) caused a decrease in TER that was reversed by IGF-I. This effect of IGF-I was associated with upregulation of COX-2 in LPS treated enterocytes. CONCLUSIONS: IGF-I enhances intestinal barrier function and reduces endotoxaemia and bacterial translocation in cirrhotic rats. IGF-I therapy might be useful in the prevention of spontaneous bacterial peritonitis in liver cirrhosis.