选择性、非选择性NOS抑制剂及L-精氨酸对创伤性休克大鼠的影响

目的探讨一氧化氮合酶（NOS）抑制剂及L-精氨酸（L Arg）对创伤性休克大鼠的治疗作用。 方法建立创伤性休克大鼠模型，随机分为对照组、左旋硝基精氨酸甲酯（L NAME）处理组、氨基胍（AG）处理组及L-精氨酸（L Arg）处理组，分别于复苏后1，4，7h检测血清一氧化氮（NO）浓度，复苏后1h检测骨骼肌、肝脏、小肠的组织氧分压，监测血液动力学变化并记录存活时间。 结果与对照组相比，L NAME可显著降低血清NO浓度，而对组织氧分压及12，24h存活率无显著影响；AG仅在休克后期使NO浓度明显降低，而对早期NO的合成与释放无显著作用，AG可提高肝脏、小肠的组织氧分压，提高休克模型12h存活率；应用L Arg可显著提高血清NO浓度，并可明显改善肝脏、小肠的组织氧分压，显著提高12，24h存活率。 结论选择性NOS抑制剂AG及L Arg更能改善创伤性休克动物模型的预后。     

Ν-硝基-L-精氨酸甲酯对大鼠隐睾生殖细胞凋亡的保护作用

目的 :探讨一氧化氮合酶 (NOS)抑制剂N 硝基 L 精氨酸甲酯 (L NAME)对大鼠隐睾生殖细胞凋亡的保护作用。　方法 :用 2 2dSD雄性大鼠复制单侧隐睾模型。实验分假手术组、隐睾组、隐睾 +L NAME组 [术后腹腔注射L NAME ,10mg/(kg·d) ],每组大鼠各 10只。术后 7d ,用生物素 dUTP/酶标亲和素测定法检测睾丸生殖细胞凋亡 ,用硝酸还原酶法测定睾丸组织中N0含量 ,用化学比色法测定睾丸组织中NOS活性。　结果 :术后第 7d ,与假手术组睾丸相比 ,隐睾组睾丸发生凋亡的生殖细胞数显著增加 ,隐睾 +L NAME组睾丸发生凋亡的生殖细胞数比隐睾组显著减少 (P <0 .0 1) ,隐睾 +L NAME组睾丸组织中NO含量及NOS活性与隐睾组相比显著降低 (P<0 .0 1)。　结论 :隐睾组织中NO和NOS升高是隐睾生殖细胞凋亡增加的病理机制之一 ,L NAME通过抑制NOS活性、减少NO的产生来降低睾丸组织生殖细胞的凋亡发挥其保护作用。     

一氧化氮合酶抑制剂对鼠急性坏死性胰腺炎的作用

一氧化氮（NO）由一氧化氮合酶（NOS）生成,已知NO与炎症过程密切相关,为了阐明原生型NOS抑制剂（NG－硝基－L－精氨酸甲基酯,L－NAME）和诱生型NOS抑制剂（氨基－乙基－异硫脲,AE－ITU）对鼠急性坏死性胰腺炎的作用,作者进行实验研究如下：取SD鼠作为实验对象,在麻醉下用蛙皮素等制成急性坏死性胰腺炎模型,共分6组,每组鼠15只：（1）盐水对照组,不制成胰腺炎模型,仅持续输往盐水每小时8ml／kg,共12小时;（2）L－NAME对照组,其手术步骤同第1组,但在第6、7和8小时各注射L－NAME30mg／kg一次;（3）AE－ITU对…     

异丙酚对大鼠肺一氧化氮合酶活性的影响

目的 了解异丙酚对大鼠肺一氧化氮合酶(NOS)活性的影响,探讨异丙酚对肺血管、支气管扩张作用的机理。方法40只SD大鼠,随机分为异丙酚组(n=20)、对照组(n=20),分别腹腔注射等容积异丙酚(1ml·kg-1,即100mg·kg-1)和生理盐水(10ml·kg-1)。异丙酚组待鼠翻正反射消失后,经尾缘静脉泵以异丙酚10mg·kg-1·h-1,20min后处死,对照组鼠腹腔注射20min后处死。检测支气管肺泡灌洗液NO水平、肺组织匀浆中NOS酶活性、NO水平及内皮型NOS(eNOS)、神经型NOS(nNOS)在肺内的表达与分布(免疫组化法)。结果 异丙酚组支气管灌洗液和肺组织匀浆中NO水平均明显高于对照组(P<0.01),肺组织匀浆中NOS酶活性也明显大于对照组(P<0.01)。异丙酚组肺血管内皮细胞nNOS和eNOS、支气管粘膜上皮细胞nNOS染色表达强阳性。结论 异丙酚可以刺激肺中NOS活性,升高肺内内源性NO水平,在异丙酚的扩张肺血管、支气管中发挥一定的作用。     

L-精氨酸在犬离体胰腺低温灌注与保存中的作用

目的　探讨L -精氨酸对犬离体胰腺低温灌注及保存中缺血再灌注损伤的影响。方法　将犬胰节段移植模型动物随机分为 3组 :(1)L -精氨酸灌注保存组 (L -arg组 ) ,在EuroCollin(EC )液中加用L -精氨酸 ;(2 )硝基精氨酸组 ,在EC液中加入N -硝基 -L -精氨酸甲酯 (L NAME) ;(3 )对照组 ,在EC液中加入生理盐水 ;分别对犬离体胰腺节段进行低温灌注保存。测定移植后犬血清中脂肪酶和淀粉酶含量 ,并测定移植胰腺组织中髓过氧化酶 (MPO )活性、一氧化氮 (NO )含量、一氧化氮合酶 (NOS)及iNOSmRNA的表达 ;同时进行组织学观察。结果　血清脂肪酶含量 :L arg组 <对照组 对照组 >L NAME组。NOS活性 :L arg组 >对照组 >L NAME组。iNOSmRNA的表达 :L arg组 >对照组 >L NAME组。MPO活性 :L arg组 <对照组 相似文献   

一氧化氮(NO)的生理作用和血管内皮细胞功能异常

NO由NO合成酶(NO synthase,以下简写作NOS)的作用,从L-精氨酸胍基生成,然后转换成瓜氨酸。在L-精氨酸胍基上,甲基(N~G-monomethyl-),硝基(N~G-mononitro-),氨基(N~G-monoamino-)附有的衍生物,作为NOS的特异基质抑制药而应用。     

诱导型一氧化氮合酶抑制剂对胃癌MFC细胞增殖与凋亡的影响

目的研究诱导型一氧化氮合酶(iNOS)选择性抑制剂氨基胍(AG)对鼠胃癌MFC细胞增殖和凋亡的影响。方法将40只MFC胃癌皮下接种模型小鼠随机分成4组对照组(等体积生理盐水)、丝裂霉素组(MMC,每周注射2次,每次0.7mg/kg)、AG组(150mg·kg-1·d-1)和MMC加AG组。均采用腹腔内注射给药法,持续14d;停药后24h处死动物。应用Greiss反应法测定荷瘤动物血浆中一氧化氮(NO)量;剥离肿瘤,称重并计算抑瘤率;应用免疫组织化学法检测肿瘤细胞中增殖细胞核抗原(PCNA)的表达,TdT介导的dUTP缺口末端标记(TUNEL)法检测肿瘤细胞的凋亡,透射电镜观察凋亡细胞的超微结构。结果AG显著降低荷瘤小鼠血浆中NO的合成,明显抑制肿瘤的生长,抑瘤率为47.1%,与对照组比较,P<0.01。AG组的肿瘤细胞PCNA表达值为25.2±3.6,MMC加AG组为22.0±3.6,明显低于对照组的82.0±3.6(P<0.01);但凋亡指数未见下降,电镜下亦未见典型的细胞凋亡形态学变化。结论AG通过抑制肿瘤组织中NO的产生而抑制肿瘤生长,但并未促进肿瘤细胞凋亡。     

异丙酚对哮喘小鼠气道高反应性和气道炎症的调节作用

目的 评价腹腔注射不同剂量异丙酚对哮喘小鼠气道高反应性、肺部炎症以及Th1/Th2平衡的调节作用.方法 健康雌性BALB/c小鼠100只,6～8周龄,体重18 ～ 20 g,采用随机数字表法,将小鼠分为5组(n=20)∶对照组(C组)、哮喘组(A组)、低剂量异丙酚组(50 mg/kg i.p.,LP组)、中等剂量异丙酚组(100 mg/kg i.p.,MP组)和高剂量异丙酚组(150 mg/kg i.p.,HP组).使用卵清蛋白(OVA)构建过敏性哮喘模型小鼠,腹腔注射-诱导过敏性哮喘模型.各组随机取10只于模型构建成功后24 h即高剂量麻醉处死,行心脏取血及支气管肺泡灌洗,以ELISA法检测血清OVA特异性IgE和支气管肺泡灌洗液中特征性细胞因子IL-4、IL-5、IFN-γ浓度,并行细胞计数/分类计数.各组剩余的10只于模型构建成功后24h行肺功能检测和取肺进行HE染色,比较各组小鼠气道反应性和肺组织的病理组织学评分.结果 腹腔注射异丙酚(LP组和MP组)可明显地抑制哮喘小鼠的气道高反应性.不同剂量异丙酚干预组(LP组、MP组和HP组)均可明显抑制哮喘小鼠肺组织中嗜酸性粒细胞浸润,降低IL-4、IL-5和血清OVA特异性IgE水平,上调IFN-γ/IL-4比值.结论 异丙酚能够有效抑制哮喘小鼠肺部炎症,上调Th1/Th2比值,改善肺功能,发挥气道保护作用.     

一氧化氮对足炎性刺激大鼠背角c-fos表达的影响

目的　应用一氧化氮合酶 (NOS)抑制剂氮ω 硝基 左旋精氨酸甲基乙酯 (L NAME)和一氧化氮 (NO)供体观察NO对单足致炎大鼠脊髓背角两侧c fos表达的影响。方法　雌性Wistar大鼠 30只 ,体重 2 5 0～ 2 80 g ,随机分为五组 :正常组、盐水对照组、致炎组、L NAME组和SNP组。盐水组、致炎组于一足底中心略凹处皮下分别注入生理盐水和 1%角叉菜胶 0 1ml。L NAME组、SNP组分别预先腹腔注射L NAME 10 0mg/kg和SNP 2mg/kg ,30min后足底 1%角叉菜胶 0 1ml致炎。所有大鼠足底注药 2h后灌杀取L5脊髓 ,冰冻切片行Fos免疫组化染色。结果　脊髓背角FLI神经元计数 :(1)致炎侧 ,各实验组均较正常组显著增加 (P <0 0 5 ) ,L NAME组较单纯致炎组显著减少 (P <0 0 5 )。 (2 )非致炎侧 ,盐水组较正常组、致炎组和L NAME组显著增加 (P <0 0 5 )。 (3)致炎组、L NAME组和SNP组的致炎侧明显高于非致炎侧 (P <0 0 5 )。结论　致炎局部产生痛觉过敏 ,远隔部位产生“抗痛反应”。NO在致炎局部痛敏形成中起一定作用 ,对远隔部位抗痛反应的作用有待进一步研究     

氨基胍对大鼠内毒素性肺损伤的影响

目的 观察诱导型一氧化氮合酶抑制剂氨基胍(AG)对内毒素性肺损伤的影响。方法 采用静脉注射脂多糖(LPS)制备内毒素性肺损伤大鼠模型。将40只SD雄性大鼠随机分为5组：空白对照组、LPS组、AG高剂量(100mg／kg)、中剂量(50mg／kg)、低剂量(25mg／kg)治疗组，LPS组、AG高剂量、中剂量和低剂量治疗组手术后稳定1h静脉注射LPS(5mg／kg)，空白对照组给等量生理盐水，AG高剂量、中剂量和低剂量治疗组于给予LPS 3h后经腹腔给AG，空白对照组和LPS组给等量生理盐水。实验过程中监测平均动脉压(MAP)，于注射LPS后1、3和6h时取静脉血0．4Tnl测定血浆NO浓度，于注射LPS 6h后处死大鼠，迅速取出肺脏，测定肺系数、肺含水量和肺组织中丙二醛(MDA)含量、一氧化氮合酶(NOS)、超氧化物歧化酶(SOD)活性的变化；在光镜下观察肺形态结构的变化。结果 LPS可明显降低MAP，升高肺系数和肺含水量，升高血浆中NO含量，可显著升高肺组织中NOS活性、增加MDA含量、降低SOD活性，引起肺形态结构的病理变化。氨基胍可明显改善吣引起的以上肺损伤，病理变化也表明：AG使肺泡萎陷明显减轻，肺间隔变窄，毛细血管增生不明显，肺间隔炎细胞浸润减轻，且高剂量比低剂量明显。结论 静脉注射LPS(5mg/kg)可成功制备大鼠内毒素性肺损伤模型；氨基胍可减轻内毒素性肺损伤，且随剂量增大作用增强。     

Effective inhibition of nitric oxide production by aminoguanidine does not reverse hypotension in endotoxaemic rats

BACKGROUND: Excess production of nitric oxide (NO) by the inducible NO synthase (iNOS) has been implicated in the pathophysiology of septic shock. Using methaemoglobin (metHb) and the stable NO metabolite nitrate as markers of NO formation, we assessed the effect of iNOS blockade by aminoguanidine (AG) on hypotension and NO formation in endotoxaemic rats. METHODS: In 32 male Wistar rats under chloralose anaesthesia, MetHb (at 15 and 330 min, respectively) and plasma nitrate (at 330 min) were determined. Mean arterial pressure, heart rate and haematocrit were monitored. The LPS group (n=8) received bacterial endotoxin (LPS), 3 mg kg(-1) i.v. and was subsequently monitored for 5 h. At 2 h after LPS, the LPS+AG20 group (n=8) received AG, 5 mg kg(-1), and 5 mg kg(-1) h(-1) for the remaining 3 h. The LPS+AG100 group (n=8) instead received 25 mg kg(-1), followed by 25 mg kg(-1) h(-1). The NaCl group (n=8) was given corresponding volumes of isotonic saline. RESULTS: AG decreased the LPS-induced rise in plasma nitrate by about 50% in the LPS+AG20 group. MetHb levels, however, were not appreciably reduced by this dose. Both NO metabolites reached control levels after the higher dose of AG. LPS caused a progressive decrease in haematocrit. AG did not influence the LPS-induced hypotension, tachycardia or haemodilution. CONCLUSION: AG inhibited NO formation in a dose-dependent way. Yet, AG had no haemodynamic effects, suggesting a minor cardiovascular influence of iNOS in this endotoxin model, in parallel to what has been found in microbial sepsis.     

Synthetic retinoids improve survival in rodent model of endotoxic shock.

OBJECTIVE: To investigate the effect of synthetic retinoids on septic shock induced by lipopolysaccharide (LPS) in rats. DESIGN: Randomised study. SETTINGS: University hospital laboratory, Sweden. ANIMALS AND INTERVENTIONS: 31 male Sprague Dawley rats randomised into four groups: controls, given vehicle alone (n = 6), LPS 6 mg/kg body weight alone (n = 12), and LPS 6 mg/kg but pretreated with the retinoic acid receptor-alpha (RAR-alpha) agonists CD336 (n = 6) and CD2081 (n = 7). MAIN OUTCOME MEASURES: Arterial blood pressure and heart rate measured hourly for four hours; mortality. RESULTS: LPS caused a pronounced fall in blood pressure within one hour of injection in all groups of rats. Of the 12 rats given LPS but not RAR-alpha agonists, 6 died before the end of the experiment. By contrast, all animal given either CD336 or CD2081 survived. The significantly improved survival was found despite no significant improvements in either mean arterial pressure or heart rate. CONCLUSION: Pretreatment with selective synthetic RAR-alpha agonists improves survival after LPS-induced septic shock in rats. These agents may have therapeutic potential in the treatment of septic shock in humans.     

诱导性一氧化氮合酶在大鼠肝缺血再灌注损伤中的作用

目的 探讨诱导性一氧化氮合酶（iNOS）在大鼠部分肝缺血再灌注损伤中的作用.方法 选取雄性Sprague-Dawley大鼠30只,体重225～250 g,随机分成氨基胍（AG）组、脂多糖（LPS）组、对照组.每组均按相同方法建立70%的肝缺血再灌注损伤模型（缺血1 h,再灌注6 h）,取再灌注大鼠肝组织及血清样本.氨基胍（AG）组（n=10）：术前30 min尾静脉注射AG 100 mg/kg（质量浓度10 kg/L）;脂多糖（LPS）组（n=10）：术前30 min尾静脉注射LPS 10 mg/kg（质量浓度1 kg/L）;对照组（n=10）：术前30 min尾静脉注射生理盐水（10 μL/kg）.检测血清谷氨酸转氨酶（ALT）水平,实时荧光定量PCR测定肝组织iNOS mRNA的表达,Western blot测定肝组织iNOS蛋白的表达,考马斯法测定肝组织匀浆丙二醛（MDA）含量、超氧化物歧化酶（SOD）活性,HE染色光镜下组织学观察等.结果 AG组与对照组相比,肝组织中iNOS mRNA表达量明显下降（P〈0.05）,iNOS蛋白表达量明显下降（P〈0.05）;ALT和MDA明显下降（P〈0.05）;SOD明显升高（P〈0.05）;肝细胞水肿较轻,排列相对整齐.LPS组与对照组相比,肝组织中iNOS mRNA表达量明显升高（P〈0.05）,iNOS蛋白表达量明显升高（P〈0.01）;ALT和MDA明显升高（P〈0.05）;SOD则明显降低（P〈0.05）;肝细胞水肿,排列紊乱,并且出现水样变性.结论 iNOS 升高会加重缺血再灌注损伤,这一过程可能通过改变氧化还原状态实现.     

Multiple Selectin Blockade With a Small-Molecule Selectin Inhibitor Does Not Affect Survival After a Second Inflammatory Challenge With Nonlethal LPS

The effects of anti-adhesion molecule antibodies on the blockade of leukocyte-endothelial interactions have the potential of decreasing survival through possibly increased infection vulnerability. The aim of this study was to determine the effect of a small-molecule selectin inhibitor (TBC-1269) on both liver response and survival to a nonlethal lipopolysaccharide (LPS) challenge after hemorrhagic shock. Ninety-six Sprague-Dawley rats were subjected to a model of uncontrolled hemorrhagic shock. Six groups of animals were included in this study ( n = 16 per group): sham/saline, sham/LPS, shock/saline, shock/LPS, shock/TBC1269, and shock/TBC-1269/LPS. Experimental design consisted of the development of hemorrhagick shock (3 mL/100 g) in a 15-min period, tail amputation and drug administration at 30 min, and subsequent resuscitation to maintain mean arterial pressure at 70mm Hg. A septic challenge was produced with 0.1 mg/kg of LPS ( Escherichia coli type 78H4086; Sigma Chemical, St. Louis, MO) given intravenously via penile vein at 20 h. Liver injury tests (alanine aminotransferase, ALT), liver myeloperoxidase, liver histology, and 21-day survival were evaluated. Statistical analysis included the Bartlett test for equality of variance, a two-way analysis of variance (ANOVA), and overall followed by pairwise log-rank test for survival. Significant improvements in liver function and histology were observed in animals treated with TBC-1269 with or without a nonlethal septic challenge. Neutrophil infiltration, as evidenced by liver myeloperoxidase (MPO) was significantly decreased in animals treated with TBC-1269 alone and those having LPS administration after TBC-1269 treatment. We conclude that TBC-1269, multisectin blocker, was effective in reducing liver damage even with the addition of a second inflammatory insult as the nonlethal LPS challenge used in this study.     

Multiple selectin blockade with a small-molecule selectin inhibitor does not affect survival after a second inflammatory challenge with nonlethal LPS.

The effects of anti-adhesion molecule antibodies on the blockade of leukocyte-endothelial interactions have the potential of decreasing survival through possibly increased infection vulnerability. The aim of this study was to determine the effect of a small-molecule selectin inhibitor (TBC-1269) on both liver response and survival to a nonlethal lipopolysaccharide (LPS) challenge after hemorrhagic shock. Ninety-six Sprague-Dawley rats were subjected to a model of uncontrolled hemorrhagic shock. Six groups of animals were included in this study (n = 16 per group): sham/saline, sham/LPS, shock/saline, shock/LPS, shock/TBC1269, and shock/TBC-1269/LPS. Experimental design consisted of the development of hemorrhagick shock (3 mL/100 g) in a 15-min period, tail amputation and drug administration at 30 min, and subsequent resuscitation to maintain mean arterial pressure at 70mm Hg. A septic challenge was produced with 0.1 mg/kg of LPS (Escherichia coli type 78H4086; Sigma Chemical, St. Louis, MO) given intravenously via penile vein at 20 h. Liver injury tests (alanine aminotransferase, ALT), liver myeloperoxidase, liver histology, and 21-day survival were evaluated. Statistical analysis included the Bartlett test for equality of variance, a two-way analysis of variance (ANOVA), and overall followed by pairwise log-rank test for survival. Significant improvements in liver function and histology were observed in animals treated with TBC-1269 with or without a nonlethal septic challenge. Neutrophil infiltration, as evidenced by liver myeloperoxidase (MPO) was significantly decreased in animals treated with TBC-1269 alone and those having LPS administration after TBC-1269 treatment. We conclude that TBC-1269, multisectin blocker, was effective in reducing liver damage even with the addition of a second inflammatory insult as the nonlethal LPS challenge used in this study.     

戊乙奎醚预先给药对大鼠内毒素性脑损伤时NF-κB和iNOS表达的影响

目的 评价戊乙奎醚预先给药对大鼠内毒素性脑损伤时NF-κB和诱导型一氧化氮合酶(iNOS)表达的影响.方法 雄性SD大鼠105只,体重200～220 g,随机分为5组(n=21),D1组、D2组或D3组分别腹腔注射戊乙奎醚0.05、0.15、0.45 mg/kg,NS组和L组给予等容量生理盐水,10min后L组、D1组、D2组和D3组经左颈内动脉注射脂多糖150 μg,NS组给予等容量生理盐水.分别于注射戊乙奎醚后4、6和12 h处死7只大鼠,取脑组织,测定脑组织含水量、NF-κB和iNOS表达水平,光镜和电镜下观察脑组织病理学结果.结果 与NS组相比,L组、D1组、D2组和D3组脑组织含水量、NF-κB和iNOS表达增加(P<0.05);与L组相比,D1组脑组织含水量、NF-κB和iNOS表达差异无统计学意义(P0.05),D2组和D3组脑组织含水量、NF-κB和iNOS表达降低(P<0.05).D2组和D3组脑组织病理学损伤轻于L组.结论 戊乙奎醚0.15、0.45 mg/kg预先给药减轻大鼠内毒素性脑损伤的机制与抑制脑组织NF-κB和iNOS表达上调有关.     

Synergistic therapeutic potential of dexamethasone and L-arginine in lipopolysaccharide-induced septic shock

BACKGROUND: Dexamethasone (DEX) is demonstrated to have anti-inflammatory properties and known to induce hemodynamic improvement in sepsis and septic shock. L-arginine (L-arg), a semi-essential amino acid, depending on its metabolic pathway, becomes very essential in stress situations such as heatstroke, burns, sepsis, trauma, and wound healing. The aim of this study was to evaluate the synergistic therapeutic effect of DEX and L-arg in rescuing the mice from experimental septic shock induced by bacterial lipopolysaccharide (LPS). The experiments were designed to delineate the molecular mechanisms responsible for the increased therapeutic benefit of the combination therapy (CT) in LPS-induced septic shock. METHODS: Acute endotoxemia was induced in Swiss male mice by i.p. injection of LPS (18 mg kg(-1)) at 0 h. LPS-treated mice were divided into four groups. The first group (DEX group) received DEX (2 mg kg(-1)) i.p. at +2 h of LPS. The second group (L-arg group) received L-arg i.p. at a dose of 120 mg/kg at +6 h of LPS injection. The third group (CT group) received DEX (2 mg kg(-1)) at +2 h LPS followed by L-arg at +6 h of LPS injection. The fourth group received saline in place of L-arg or DEX (LPS group). A sham group was also included, where normal mice received saline in place of LPS or L-arg or DEX. At +6 h, mice from sham group, LPS group, and DEX group were sacrificed at +24 h. Mice from sham group, DEX group, L-arg group, and CT group were sacrificed to examine various parameters associated with LPS endotoxemia. RESULTS: The CT with DEX followed by L-arg significantly increased the survival of mice injected with a lethal dose of LPS. Monotherapy with either DEX or L-arg given at the same dose and time did not increase the survival of the mice injected with LPS. DEX administration could significantly reduce the levels of serum TNF-alpha, IL-1beta, IFN-gamma, aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), and nitrite. DEX also down-regulated the expression of liver-inducible nitric oxide synthase (iNOS), and up-regulated the levels of serum anti-inflammatory cytokines like TGF-beta1 and IL-4, hepatic and splenic arginase, in LPS-injected mice. The enhanced therapeutic effect of CT correlated with reduced pathological symptoms, decreased Th1 cytokines, increased TGF-beta1 and arginase levels compared to the mice administered with either of the monotherapies. The CT group had significantly increased expression of hepatic Hsp 70 and reduced septic shock associated histopathology, in lung and liver, compared to the mice treated with either DEX or L-arg. CONCLUSIONS: The therapeutic combination therapy with DEX and L-arg, at the appropriate dose, time, and sequence of administration, changed the cytokine profile, in favor of reducing the inflammatory response. The significantly enhanced survival observed in the CT group was accompanied by an increased hepatic Hsp 70, hepatic arginase, splenic arginase, and decreased organ injury. This novel concept of combined therapy could form the basis of an effective therapeutic approach in the treatment of sepsis and septic shock.     

氨基胍对内毒素休克大鼠肝损伤的保护作用研究

目的 探讨诱导型一氧化氮合酶(iNOS)抑制剂氨基胍对内毒素休克大鼠肝脏的组织学和超微结构的影响。方法 取雄性wistar大鼠24只．随机分为正常对照组、内毒素对照组和氨基胍治疗组．每组各8只。用大肠杆菌内毒素(LPS)复制大鼠内毒素性休克模型．氨基胍治疗组采用氨基胍治疗。观察并比较三组大鼠肝脏的组织学、超微结构及其血浆一氧化氮(NO)含量的变化。结果 光镜下可见．内毒素组肝组织有散在小脓肿灶形成．肝细胞坏死，中性白细胞浸润．而氨基胍治疗组的肝组织受损程度较轻。电镜下可见，内毒素组的肝细胞核出现融解性空斑．线粒体肿胀和线粒体嵴数量减少．而氨基胍则对肝脏的结构起到一定的保护作用。内毒素对照组血浆NO水平明显高于正常对照组．给予氨基胍治疗后血浆NO水平明显下降．但仍高于正常对照组。结论 氨基胍通过选择性抑制iNOS活性．抑制了大鼠内毒素休克时过量的NO的产生．保护了肝脏的功能．具有潜在的临床应用价值．值得更深入地研究。     

Role of inducible nitric oxide synthase in pig liver transplantation

BACKGROUND: Previously, we clarified the role of inducible nitric oxide synthase (iNOS) and the protective effect of an iNOS inhibitor in warm ischemia and reperfusion model. In this study, we investigated whether the same effects would be obtained by iNOS inhibitor in liver transplantation model. MATERIAL AND METHODS: Orthotopic liver transplantation was performed in pigs in the usual manner after about 6 h of cold preservation in University of Wisconsin solution. Aminoguanidine hemisulfate (AG) was used as the iNOS inhibitor and AG was administered intraportally at the dose of 10 mg/kg just after reperfusion. Two experimental groups were subjected, control group (n = 10), and AG group (n = 10). We investigated changes of serum nitrite/nitrate (NOx) and aspartate aminotransferase (AST). Expression of iNOS was examined by immunohistochemistry, including a double immunofluorescnce technique in combination with cofocal laser scanning microscopy. RESULTS: Serum NOx and AST were significantly lower in the AG group. Histological hepatic damage and thrombocyte thrombi were attenuated in the AG group. Expression of iNOS was recognized strongly at Kupffer cells and neutrophils in the centrilobular region of liver after reperfusion by cofocal laser scanning microscopy. Moreover, iNOS staining was attenuated in AG group compared with control group. CONCLUSIONS: These results indicate that hepatic ischemia and reperfusion injury in liver transplantation might be triggered by iNOS expression of Kupffer cells and neutrophils, and attenuated by administration of an iNOS inhibitor. Moreover, AG showed down regulation of iNOS expression after reperfusion.