人参总皂甙对犬肾自体移植再灌注损伤中氧自由基的清除作用

为了解人参总皂甙对肾移植再灌注损伤中氧自由基（ＯＦＲ）的清除作用，采用犬肾移植模型观察再灌注后２４小时肾组织中超氧化物歧化酶（ＳＯＤ）和丙二醛（ＭＤＡ）含量的变化及移植前后不同时期内生肌酐清除值。结果发现，在肾缺血和再灌注损伤过程中肾组织ＳＯＤ活性下降，ＭＤＡ含量异常增高。给人参总皂甙后能显著减少肾组织中ＭＤＡ含量，提高ＳＯＤ活性及内生肌酐清除值。结果提示，人参总皂甙能清除肾脏再灌注损伤产生的ＯＦＲ，保护内源性ＳＯＤ活性，减轻肾脂质过氧化损伤。     

丹参提取物F在再灌注损伤中对胃粘膜抗氧化能力影响

目的：探讨丹参提取物Ｆ的胃粘膜保护作用与氧自由基的关系。方法：复制失血性休克再灌注损伤模型,３１只大鼠随机分为单纯失血组（ＨＥ,ｎ＝９）,生理盐水对照组（ＮＳ,ｎ＝１０）及丹参提取物Ｆ组（ＤＳＥＦ,ｎ＝１２）;ＨＥ组大鼠在失血性休克２０ｍｉｎ后处死,ＮＳ及ＤＳＥＦ组则在休克２０ｍｉｎ后回输全部放出的血液,维持２０ｍｉｎ后处死。其中ＮＳ组静滴ＮＳ００３ｍｌ／ｍｉｎ,ＤＳＥＦ组静滴ＤＳＥＦ１ｇ／１００ｇｗｔ。结果：ＨＥ组损伤指数为０,ＤＳＥＦ组损伤指数明显低于ＮＳ组（Ｐ＜００１）,ＤＳＥＦ组的丙二醛（ＭＤＡ）含量明显低于ＮＳ组（Ｐ＜００１）,而超氧化物歧化酶（ＳＯＤ）活性明显高于ＮＳ组（Ｐ＜００１）。结论：ＤＳＥＦ在再灌注损伤中可减轻氧自由基对胃粘膜的损伤     

联合应用超氧化物歧化酶,阿魏酸钠抗肝缺血再灌注损伤

目的研究联合应用外源性超氧化物歧化酶（ＳＯＤ）与阿魏酸钠（ＳＦ）对肝缺血再灌损伤的保护作用。方法将３２只成年雄性ＳＤ大鼠随机分为对照组、ＳＦ保护组、ＳＯＤ保护组和ＳＦ与ＳＯＤ联合保护组。通过阻断大鼠肝门１ｈ后再开放建立肝缺血再灌注损伤模型,在肝缺血前及肝再灌注２ｈ时测肝组织丙二醛（ＭＤＡ）,ＳＯＤ和测血谷丙转氨酶（ＡＬＴ）,谷草转氨酶（ＡＳＴ）。并取肝组织作光镜及电镜观察。结果再灌注２ｈ时ＳＦ保护组与ＳＯＤ保护组的肝组织ＭＤＡ生成,ＳＯＤ消耗,血清ＡＬＴ,ＡＳＴ升高值均高于ＳＦ与ＳＯＤ联合保护组（Ｐ＜０．０１或Ｐ＜０．０５）,且ＳＦ和ＳＯＤ联合保护组的肝细胞显微、超微结构损害的改变较ＳＯＤ或ＳＦ保护组轻。结论ＳＦ与ＳＯＤ联合保护组清除氧自由基（ＯＦＲ）的作用强于ＳＯＤ或ＳＦ保护组,对鼠肝缺血再灌注所致肝细胞的结构和功能损伤的保护作用比单独使用ＳＯＤ或ＳＦ强。     

参附注射液对缺血再灌注家兔多脏器损伤的治疗作用

目的：观察参附注射液（ＳＦ）对缺血再灌注家兔多脏器细胞损伤的保护作用。方法：家兔１８只，采用失血性休克模型，随机分为三组，检测多脏器组织中ＳＯＤ、ＭＤＡ、ＴＮＦ含量及血浆酸性磷酸酶（ＡＣＰ）、镁浓度，小肠组织作透射电镜观察。结果：再灌９０分钟后ＳＦ治疗组肝、肾、肺、肠组织中的ＭＤＡ和ＴＮＦ水平低于对照组，ＳＯＤ水平则高于对照组，血ＡＣＰ、Ｍｇ２＋浓度治疗组低于对照组。电镜观察，肠粘膜上皮细胞损伤ＳＦ组不明显。结论：ＳＦ对兔缺血再灌注多脏器细胞的损伤有保护作用。     

丹参及血栓通注射液对缺血再灌注大鼠肾脏的影响

丹参及血栓通注射液对缺血再灌注大鼠肾脏的影响徐幼筠，杜学海，邹万忠ＴＨＥＥＦＦＥＣＴＯＦＳＡＬＶＩＡＥＭＩＬＴＩＯＲＲＨＩＺＡＥ（ＳＭ）ＡＮＤＡＲＡＳＡＰＯＮＩＮ（ＡＲ）ＯＮＩＳＣＨＥＭＩＡ－ＲＥＰＥＲＦＵＳＩＯＮＲＡＴＫＩＤＮＥＹＸｕＹｏｕｊｕｎ；...     

肾脏缺血再灌注损伤研究进展

肾缺血再灌注损伤不仅可发生在肾移植中,而且在复杂的肾脏手术、休克复苏过程中亦可出现。本文回顾了近年来有关肾缺血再灌注损伤机制及保护作用等方面的研究,综述如下。１损伤机制１．１氧自由基 氧自由基（ＯＦＲ）是分子氧还原为水的一系列单价途径中所产生的中间产物,包括超氧阴离子自由基（Ｏ２－）、羟基自由基（ＨＯ－）、过氧化氢（Ｈ２Ｏ２）和单线态氧（Ｏ２）,由于有超氧化物岐化酶（ＳＯＤ）、过氧化氢酶（ＣＡＴ）、过氧化物酶等能迅速将ＯＦＲ清除而不造成ＯＦＲ堆积［１］ 在肾脏缺血情况下,可出现下面两种后果：①ＡＴ…     

参麦注射液抗肝缺血再灌注损伤的研究

目的：研究参麦注射液对肝缺血再灌注损伤的保护作用。方法：将３７只成年雄性ＳＤ大鼠随机分成假手术对照组（ＳＯＣ）、缺血再灌注组（Ｉ／Ｒ）、缺血再灌注加参麦组（Ｉ／Ｒ＋ｓｈｅｎｍａｉ）。通过阻断大鼠肝门３０ｍｉｎ后再开放建立肝缺血再灌注损伤模型,在肝脏再灌注９０ｍｉｎ时测肝组织丙二醛（ＭＤＡ）、超氧化物歧化酶（ＳＯＤ）和测血ＡＬＴ、ＡＳＴ、ＬＤＨ,并取肝组织作光镜及电镜观察。结果：再灌注９０ｍｉｎ时Ｉ／Ｒ＋Ｓｈｅｎｍａｉ组的肝组织ＭＤＡ生成,ＳＯＤ消耗,血清ＡＬＴ、ＡＳＴ、ＬＤＨ升高值均少于Ｉ／Ｒ组（Ｐ＜０．０１）,且Ｉ／Ｒ＋Ｓｈｅｎｍａｉ组的肝细胞显微、超微结构损害的改变较Ｉ／Ｒ组轻。结论：参麦注射液能清除肝缺血再灌注过程中产生的氧自由基,对鼠肝缺血再灌注所致肝细胞的结构和功能损伤有保护作用     

一氧化氮在大鼠肝硬变门静脉高压症形成中的作用及其对血液动力学的影响

目的探讨一氧化氮（ＮＯ）在肝硬变门静脉高压症（ＰＨＴ）形成过程中的作用。方法采用比色法和鲎试验改良基质显色法，对大鼠肝硬变ＰＨＴ形成过程中，外周血ＮＯ、内毒素浓度和血液动力学的变化进行检测，观察了ＮＯ合成酶抑制剂Ｌ－ＮＭＭＡ对ＰＨＴ大鼠血液动力学的影响。结果（１）在大鼠肝硬变ＰＨＴ形成过程的早、中、晚三期，血浆ＮＯ和内毒素水平显著升高。（２）在肝硬变形成各期门静脉阻力（ＰＶＲ）和门静脉压力（ＰＶＰ）均显著升高，平均动脉压（ＭＡＰ）和内脏血管阻力（ＳＶＲ）显著下降，门静脉血流量（ＰＶＦ）变化不明显。（３）ＮＯ水平和内毒素、ＰＶＰ呈显著正相关。（４）注射Ｌ－ＮＭＭＡ，肝硬变大鼠ＭＡＰ、ＳＶＲ、ＰＶＲ显著升高；ＰＶＦ显著下降；ＰＶＰ变化不明显。结论ＮＯ参与了ＰＨＴ时高动力循环状态的形成，在肝硬变ＰＨＴ的形成和维持中起着重要的作用     

不同灌注途径在鼠肝隔离灌注5－FU时肝组织与周围血中药物液度测定的比较

我们按Ｗｉｇｇｅｒ法建立失血性休克晚期家兔模型。结果发现失血性休克晚期家兔红细胞超氧化物歧化酶（ＳＯＤ）活性明显下降，血浆丙二醛（ＭＤＡ）、血液乳酸盐（ＢＬ）及血浆镁离子（Ｍｇ２＋）浓度显著上升，提示失血性休克晚期存在由氧自由基所致的细胞膜脂质过氧化损伤。我们将丹参＋川芎嗪或三七十川芎联合用药治疗失血性休克晚期家兔，可明显提高ＳＯＤ活性，降低ＭＤＡ、ＢＬ及Ｍｇ２＋浓度。与单一药物组相比，证实前者可减半用药剂量，达到减轻其降压、法慢心率等负性变力变频作用，但却可取得超过各单一药物应用全量时的清除氧自由基效果。丹参正交实验结果显示：再灌注前若经动脉途径先轮入丹参，再同时使用携平衡盐液治疗，则可使组织细胞的损伤减轻到最低程度。     

失血性休克中丹参和超氧化物歧化酶抑制脂质过氧化反应的研究

观察了复方丹参液及ＳＯＤ对失血性休克家免再灌注血液及组织（肝、肠）脂质过氧化反应的影响。结果表明，丹参及ＳＯＤ均能有效降低休克再灌注动物血液脂质过氧化反应程度，丹参降低组织（肠）脂质过氧反应作用优于ＳＯＤ。本实验将１８只失血性休克家兔随机分为三组。休克９０分后，回输放血总量的１／３血液，同时各组动物分别输注平衡盐液（Ａ组）、含ＳＯＤ平衡盐液（Ｂ组）及含复方丹参液平衡盐液（Ｃ组）。Ａ组再灌注后血清ＭＤＡ显著增加，ＭＡＰ逐渐下降，组织（肠、肝）ＭＤＡ含量较高。而Ｂ组及Ｃ组再灌注后血清ＭＤＡ迅速下降，于再灌注３小时恢复至休克前水平，并显著低于Ａ组，且ＭＡＰ进行性升高，于再灌注第３小时显著高于Ａ组。再灌注３小时时Ｃ组肠组织ＭＤＡ含量显著低于Ａ组（Ｐ＜０．０１）及Ｂ组（Ｐ＜０．０５），而肝组织ＭＤＡ含量各组无显著差别。丹参降低组织（肠）脂质过氧化反应作用优于ＳＯＤ，可能与丹参分子量小、容易透过细胞膜以及丹参的组织分布较快等有关。     

Portal hypertension predisposes the gastric mucosa to hemorrhagic shock/reperfusion injury

We have previously demonstrated that the portal hypertensive (PHT) gastric mucosa has unique functional and morphologic features which predispose it to increased damage by noxious agents such as aspirin or alcohol. In this study we examine the PHT gastric mucosa following hemorrhagic shock and reperfusion. Portal hypertension was produced in 12 rats using staged portal vein occlusion, and seven animals (controls) underwent sham procedures. All rats received 2 ml 0.1 N HCl intragastrically. Shock was then induced by withdrawing blood to reduce systemic arterial pressures to approximately 30 mm Hg for 20 min. Blood was then reinfused and stomachs were excised 20 min later for gross and microscopic quantitation of injury. We found that gross damage to gastric glandular mucosa was more than doubled in PHT rats over sham-operated controls. In PHT gastric mucosa, deep histologic necrosis involved 22.5 +/- 3.8% of mucosal section lengths compared with 6.9 +/- 2.0% in control mucosa (P less than 0.005). Histologically, mucosal injury patterns were predominantly ischemic, with deep necrosis and disintegration of glands and microvessels, all prominently more extensive in PHT mucosa. We conclude that PHT gastric mucosa has significantly increased susceptibility to damage following hemorrhagic shock/reperfusion compared with portal normotensive mucosa. Since hemorrhagic shock is a frequent complication of portal hypertension, this study suggests clinical investigations of gastric mucosal function and pathophysiology in PHT patients following hemorrhage and resuscitation.     

氧自由基在肝脏保存再灌注损伤中的作用及丹参的保护作用

目的 探讨氧自由基在肝脏保存再灌注损伤（ｈｅｐａｔｉｃ ｐｒｅｓｅｒｖａｔｉｏｎ ｒｅｐｅｒｆｕｓｉｏｎ ｉｎｊｕｒｙ,ＨＰＲＩ）中的作用及丹参的保护作用。方法 建立大鼠肝脏保存再灌注模型,分别检测肝脏保存０、８、１６、２４、３２小时组在不同灌注时间点组织超氧化物酶（ＳＯＤ）、丙二醛（ＭＤＡ）和灌注液俗 草转氨酸（ＡＳＴ）的变化,并观察肝细胞形态学的改变。结果 与正常组（保存０小时组）比较,保存１     

Reduction of ethanol-induced injury in portal hypertensive gastric mucosa of rats by induction of heat shock protein 72 by geranylgeranylacetone

Portal hypertensive (PHT) gastropathy has an increased susceptibility to damage due to noxious factors. Heat shock protein (HSP) 72 has a protective effect against gastric mucosal injury and geranylgeranylacetone (GGA) is an inducer of HSP 72. However, it remains unclear how HSP 72 influences the PHT gastric mucosa. The aim of the present study was to investigate HSP 72 induction by GGA and the protective effect to gastric mucosa in PHT rats. PHT rats were produced by staged portal vein occlusion, and GGA 200 mg/kg was orally administered. Expression of HSP 72 protein in the gastric mucosa was evaluated by enzyme-linked immunosorbent assay, and gastric mucosal damage against 70% ethanol (10 mL/kg) following GGA or vehicle treatment was also estimated. Expression of mucosal HSP 72 after vehicle administration was significantly higher in the PHT rats compared with the sham-operated rats. After GGA treatment, portal pressure did not change but HSP 72 was significantly increased in the gastric mucosa of both groups. Ethanol-induced gastric mucosal damage was significantly decreased due to GGA treatment in the PHT rats, but not in the sham-operated rats. These findings suggest that HSP 72 expression is enhanced in PHT gastric mucosa and plays an important role in gastric mucosal protection. The induction of HSP 72 by GGA may therefore effectively prevent mucosal injury in the PHT stomach.     

Epidermal growth factor protects portal hypertensive gastric mucosa in ischemia/reperfusion: the role of capillary endothelia and prostaglandins.

BACKGROUND. Epidermal growth factor (EGF) protects gastric mucosa against a variety of injurious agents, but the mechanism is unclear. Because the abnormal microvasculature of portal hypertensive (PHT) gastric mucosa is a major target of ischemia/reperfusion (I/R) injury, we used this model to assess EGF's protective role at the microvascular level. METHODS. Rats with PHT (staged portal vein ligation) received either EGF, 20 micrograms/kg, or saline solution intravenously, with or without indomethacin pretreatment (20 mg/kg subcutaneously). I/R was produced by withdrawing blood to systemic pressures of 30 mm Hg for 20 minutes and reinfusing it. Stomachs were excised 20 minutes later and evaluated for gross and histologic necrosis, microvascular permeability, mucosal ultrastructure and vimentin, and cyclooxygenase immunofluorescence. RESULTS. In saline-treated rats, gross and histologic damage involved 46% +/- 3% of glandular mucosa and 23% +/- 3% of mucosal sections, respectively. Microvascular permeability was increased 43-fold over that of normal control rats. Vimentin immunofluorescence intensity was reduced to 36% +/- 4% that of normal control rats. EGF pretreatment reduced histologic necrosis to 2% +/- 1% (p less than 0.01). Microvascular permeability and vimentin intensity were almost normalized. Indomethacin partially reversed the mucosal protection induced by EGF. CONCLUSIONS. EGF significantly reduces I/R injury to PHT gastric mucosa. Microvascular endothelia of PHT gastric mucosa are the major target of I/R injury and the site of EGF's protective action. Prostaglandins in part mediate EGF's protective action.     

New insights into impairment of mucosal defense in portal hypertensive gastric mucosa

Portal hypertension (PHT) increases susceptibility of the gastric mucosa to injury. The aim of this study was to investigate whether PHT affects rat gastric mucosal defense mechanisms in vivo at the preepithelial, epithelial, and/or post-epithelial levels. PHT was produced in rats by staged portal vein ligation and sham-operated (SO) rats served as controls. The gastric mucosa was exposed, chambered, and continuously superfused with buffers under in vivo microscopy. We measured gastric mucosal gel layer thickness, surface epithelial cell intracellular pH (pH₁), mucosal blood flow, and mucosal/serosal oxygenation. In PHT rats, gastric mucosal gel layer thickness was significantly reduced (88 ±16 μm in PHT rats vs. 135 ±25 μm in SO rats; P <0.0001), and the surface epithelial cell pH₁ was significantly decreased (6.80 ± 0.11 in PHT rats vs. 7.09 ± 0.21 in SO rats; P <0.01). Although total gastric mucosal blood flow was significantly increased in PHT rats by 72 % (P <0.05), the oxygenation of the gastric mucosal surface was decreased by 42 % (P <0.05) compared with SO rats. PHT impairs pre-epithelial (mucosal gel layer thickness), epithelial (pH₁), and post-epithelial (maldistribution of blood flow) components of the gastric mucosal barrier. These findings can explain the increased susceptibility of portal hypertensive gastric mucosa to injury. Supported by Veterans Affairs Medical Research Service Merit Review Awards (J.D.K., I.J.S., and AS.T.) and a REAP award. Presented at the Fortieth Annual Meeting of The Society for Surgery of the Alimentary Tract, Orlando, Fla., May 16–19, 1999.     

大鼠肝脏缺血再灌注及低温保存过程中氧自由基变化的实验研究

目的　观察大鼠肝脏缺血再灌注及低温保存过程中氧自由基的变化。方法　建立大鼠肝脏假手术、热缺血再灌注和原位肝移植模型 ,分别测定再灌注 1h和移植术后 2h下腔静脉血中超氧化物歧化酶 (SOD)、乳酸脱氢酶 (LDH)和血清中脂质过氧化物酶 (LPO)的变化 ,并进行组织学观察。结果　术前 30min静脉注射别嘌醇或灌洗液及保存液中加别嘌醇的实验组大鼠 ,其全血中SOD的活力高于条件相同、但不给予别嘌醇的对照组 ,LPO及LDH的含量低于对照组 ,其各项测定值与假手术组比较 ,差异不显著 ;实验组和假手术组的大鼠肝组织病理改变均轻于对照组。结论　大鼠肝脏缺血再灌注及低温保存过程中氧自由基明显增加 ,并且造成肝脏的损害     

Overexpression of inducible nitric oxide synthase in gastric mucosa of rats with portal hypertension: correlation with gastric mucosal damage

BACKGROUND: An increased biosynthesis of nitric oxide (NO) has been implicated in the hyperdynamic circulation and development of collaterals of portal hypertension (PHT) because of its potent vasodilatory effects. NO is synthesized from L-arginine by three different isozymes of nitric oxide synthase (nNOS, iNOS and eNOS). Thus, the expression of inducible NOS (iNOS) might account for NO overproduction in PHT. However, in previous investigations, the role of iNOS in the pathogenesis of PHT gastropathy remained controversial. Our current study was in both molecular and protein levels to determine whether the expression of iNOS is responsible for PHT gastropathy. MATERIALS AND METHODS: PHT was induced experimentally by partial ligation of the portal vein. Fourteen days after partial ligation of the portal vein, the rats were randomly assigned to receive either vehicle or L-NAME (NOS inhibitor) at doses of 5 mg/kg/day, 10 mg/kg/day, or 25 mg/kg/day by gastric lavage twice a day for 1 week. Sham operated rats served as controls. Northern hybridization and in situ hybridization are used to compare the expression of gastric mucosa iNOS mRNA in the PHT rats and the controls. NO was measured by the Griess method after reduction of nitrate to nitrite with nitrate reductase. Immunohistochemical staining was carried out to detect the iNOS protein. In addition, the severity of gross gastric mucosal lesions was evaluated macroscopically by a gross ulcer index. RESULTS: The iNOS expression at both mRNA and protein was prominently increased in PHT rats, accompanied with the enhanced NO production. The gastric mucosa iNOS mRNA and serum NO levels were significantly decreased after L-NAME administration (P < 0.05). However, the markedly reduced gastric mucosal damage in PHT rats was observed only at high does of L-NAME (25 mg/kg/day) administration. CONCLUSION: PHT triggers overexpression of iNOS mRNA and proteins in rat gastric mucosa, but that this alone does not account for PHT gastropathy.     

The effect of portal hypertension on the glycoprotein biosynthesis of rat gastric mucosa.

The aim of this study was to assess the influence of epidermal growth factor (EGF) on glycoprotein biosynthesis in portal hypertensive (PHT) gastric mucosa. Portal-vein ligation (PVL) for a period of 4 weeks was applied to 40 male Wistar rats to produce experimental portal hypertension. The rats were subdivided into four groups. Human EGF was administrated to these four groups of animals at a does of 0, 10, 25, and 50 microg/kg/day for 7 days. An additional group of 10 rats without PVL and EGF pretreatment was employed as a control. The severity of gross gastric mucosal lesions was evaluated macroscopically by a gross ulcer index. Glycoprotein biosynthesis of the gastric mucosa was determined by the incorporation rate of [(3)H]glucosamine. Quantitative changes of gastric mucosal hexosamines were also used for mucosal glycoproteins analyses. The gross mucosal damage was considerably greater in the PVL group without EGF pretreatment than in the EGF-pretreated groups (p <.05). The incorporation rate of [(3)H]glucosamine was significantly higher in the control group and the EGF-pretreated groups than in the PVL group without EGF pretreatment (p <.05). Moreover, the incorporation rate of [(3)H]glucosamine and the gastric mucosal hexosamine content were closely relevant to administration does of human EGF (p <.001). In addition, the reduction of glycoprotein biosynthesis was closely related to the increase in portal pressure (p =.001) and the severity of portal hypertensive gastropathy (p <.001). Our current study shows that the rate of incorporation of glucosamine is decreased in the PHT gastric mucosa and that EGF significantly stimulated glycoprotein synthesis in the PHT gastric mucosa. Accordingly, these findings may be helpful to explain the protective effect of EGF on the PHT gastric mucosa via increased glycoprotein biosynthesis in the stomach.     

Gastric mucosal perfusion and injury: variation in the relationship over time

Acute erosions of the gastric mucosa occur in a variety of clinical settings characterized by a mismatch between mucosal blood supply and demand. Using a canine model incorporating the clinically important insults, we examined the relationship between the gastric mucosal injury measured by planimetry and the animal's regional gastric perfusion measured before, during, and after hemorrhagic shock. The proximal gastric mucosa developed lesions which were inversely related to the amount of gastric flow through 2 hours of shock. In later shock and after reperfusion the relationship reversed, coinciding with the appearance of visible ulcerations. This work demonstrates that early in shock gastric blood flow is inversely related to mucosal injury, but late in shock and after reperfusion increased blood flow is associated with increased mucosal damage.