Antioxidants vitamin E and C attenuate hepatic fibrosis in biliary-obstructed rats

INTRODUCTION Hepatic fibrosis is a highly integrated cellular response to tissue injury[1]. It is essentially characterized by activation of hepatic stellate cells, secretion and accumulation of extracellular matrix proteins[2]. Various causes of cholesta…     

干扰素α对实验大鼠肝内纤维组织及肝星状细胞的影响

目的 探讨干扰素(IFN)α防治肝纤维化作用机制。方法 雄性SD大鼠54只分成A组(正常对照组)6只、B组(模型对照组)12只、C组(IFNα预防组)12只、D组(IFNα治疗组)12只和E组(生理盐水对照组)12只。分别于实验6～12周末处死,取肝组织行病理组织学与电镜下同步观察。结果 B组大鼠肝内纤维组织广泛增生,假小叶形成,活化的肝星状细胞(HSC)明显增多,C组和D组肝内纤维组织明显减轻,活化HSC数量减少,凋亡数目明显增多。结论 IFNα通过抑制HSC活化并诱导其凋亡防治肝纤维化形成。     

维生素E抗大鼠四氯化碳所致肝纤维化的实验研究

目的为探讨维生素Ｅ（ＶＥ）对肝纤维化的治疗作用。方法观察了ＶＥ对四氯化碳（ＣＣＩ４）诱导的肝纤维化大鼠肝功能，脯氨酸肽酶（ＰＬＤ）、透明质酸（ＨＡ）、丙二醛（ＭＤＡ）、超氧化物歧化酶（ＳＯＤ）及肝脏组织学的影响。同时没有正常对照、溶剂对照及空白对照组。结果维生素Ｅ治疗１０周后，上述生化指标除ＨＡ（３８７．５７±１２９．３９ｎｇ／ｍｌ）仍示达正常外，其余各指标均恢复正常，其中ＡＬＴ于第２周后、ＰＬＤ和ＭＤＡ于第４周后恢复。溶剂对照及空白对照组在第１０周时各指标虽有下降，仍高于ＶＥ治疗组（Ｐ＜０．０１，Ｐ＜０．０５）；光镜观察治疗组大鼠肝内网状纤维由粗大变纤细并有缩短和断裂，经真彩色图像系统分析与对照组比较差异有显著性（Ｐ＜０．０１）。结论ＶＥ治疗有助于实验性四氯化碳肝纤维化的恢复。     

抗纤二号抗大鼠肝纤维化的实验性研究

目的探讨复方抗纤二号抗肝纤维化的治疗机制.方法雄性Wistar大鼠分成5组,除正常对照外,余4组均腹腔注射猪血清（0.5 ml/次,2次/周,共12周）用作肝纤维化造模.抗纤二号早期治疗组B在第3周给予中药灌胃,1 ml/100g体重,每天一次.抗纤二号晚期治疗组C在第9周给予中药灌胃,1 ml/100 g体重,每天一次.γ-干扰素治疗组D在第9周每天皮下注射10万单位的干扰素.模型组A和正常对照组N给等量的生理盐水灌胃.12周末杀大鼠,苏木精-伊红染色和Masson染色观察肝纤维化的形成,免疫组织化学观察平滑肌肌动蛋白（SMA）的表达.同时逆转录聚合酶链反应（RT-PCR）检测肝组织中SMA、Ⅰ、Ⅲ胶原和转化生长因子β1（TGF-β1）下游信号Smad3 mRNA的表达.结果抗纤二号治疗组B和C与模型组比较,体重较重,肝脏、脾脏变小,肝重/体重和脾重/体重降低（P＜0.05）.病理学观察,抗纤二号治疗组B显著逆转了免疫性大鼠的肝纤维化.苏木精-伊红染色和Masson染色显示抗纤二号治疗组B胶原明显减少（P＜0.05）.逆转录聚合酶链反应分析SMA、Ⅰ、Ⅲ型胶原和Smad3 mRNA的表达在抗纤二号治疗组均明显减少（P＜0.05）.免疫组织化学观察SMA的表达在抗纤二号治疗组均明显降低,同时分析表明Smad3 mRNA与Ⅰ、Ⅲ胶原mRNA存在正相关（r=0.890）.结论抗纤二号能逆转免疫性肝纤维化,这是由于能部分抑制肝星状细胞的增殖和抑制肝纤维化有关的细胞因子TGF-β1下游信号Smad3的表达.     

Role of hepatic vitamin A and lipocyte distribution in experimental hepatic fibrosis

ABSTRACT— Lipocytes are the major site of hepatic vitamin A storage, and they have been demonstrated to lose their vitamin A content in the process of hepatic fibrosis. To investigate the relationship between hepatic vitamin A content and the degree of hepatic fibrosis, we measured levels of retinyl palmitate and retinol in the CCl₄-induced fibrotic liver using high-performance liquid chromatography. We estimated hepatic collagen content using a spectrophotometric analysis with sirius red, and also by measuring hydroxyproline levels. Lipocytes were detected by an immunoperoxidase method with anti-desmin antibody, and were counted morphometrically through a Texture Analyzing System. A significant negative correlation was observed between the level of retinyl palmitate and collagen content (r = –0.64) as well as the hydroxyproline level (r = –0.69) in the CCl₄-induced fibrotic liver. In the process of fibrosis, hepatic retinol levels were elevated in association with a decrease in retinyl palmitate. In particular in the early stage of fibrosis, lipocytes increased remarkably in number in fibrotic areas in spite of a decrease in total hepatic vitamin A. The present study suggests that an increase in hepatic retinol as well as a decrease in retinyl palmitate may facilitate the process of hepatic fibrosis produced by lipocytes.     

大黄素抗肝纤维化作用的实验研究

目的 研究大黄素抗肝纤维化作用。方法 采用40％四氯化碳给大鼠皮下注射制备肝纤维化模型并以小、中和大剂量大黄素（20mg/kg、40mg/kg和80mg/kg体重）干预,测定肝功能、血清透明质酸、层粘连蛋白及肝组织胶原蛋白,并通过光镜观察肝组织病理变化,免疫组织化学法检测肝组织α－肌蛋白表达。结果 大黄素组较模型组：（1）肝功能明显改善：谷氨酸转氨酶及碱性磷酸酶显著降低,总蛋白及白蛋白显著升高;（2）血清透明质酸及层粘连蛋白显著降低;（3）肝组织胶原蛋白含量明显减少;（4）肝组织纤维化程度明显改善;（5）肝组织α－肌动蛋白表达减少。结论 大黄素具有抗肝纤维化作用。     

螺内酯防治实验性大鼠肝纤维化作用研究

探讨螺内酯对肝纤维化的防治作用。雄性SD大鼠46只,随机分成对照组(6只);模型组(30只),复合因素制成肝纤维化模型;螺内酯预防组(10只),造模方法同模型组,螺内酯每天100mg·11ml灌胃。于第8W末,将模型组(16只)再随机分为A组(肝硬化组)8只,用等量自来水灌胃;B组(螺内酯治疗组)8只,螺内酯灌胃8w。分别观察肝内纤维组织变化。显示螺内酯预防组肝脏I、Ⅲ型胶原、纤维连接蛋白、层粘蛋白增生明显减低(PO.05)。     

Effect of vitamin E on experimental inflammation in rats

Besides other mediators like prostaglandins, kinins and histamine, oxygen radicals potentiate inflammations. Vitamin E as natural antioxidant could scavenge radicals produced during an inflammation and therefore reduce the inflammatory response. In experiments with male Wistar rats maintained on a diet deficient in or supplemented with vitamin E for 6 weeks the influence of the administration of DL-alpha-tocopherol on the inflammation of the right hind paw was tested. The irritation produced by injection of Freund's complete adjuvants was observed for 21 days. Measuring the thickness of the paw and the activity of acid phosphatase in the paw tissue there was no difference in the intensity of inflammation among the control and the vitamin-E-deficient diet groups. The supplementation with a pharmacological dose of tocopherol (324 mg DL-alpha-tocopherol/100 g food) had no effect on the inflammation of animals with different vitamin E supplements. Differences in the antioxidant status (contents of tocopherol and malondialdehyde in several organs, activity of creatine kinase in plasma) among the groups were mainly linked to the various tocopherol supplies. The irritation increased the lipid peroxidation in liver mitochondria and the activity of creatine kinase in the plasma. The data show no influence of vitamin E on this kind of inflammation.     

安络化纤丸对二甲基亚硝胺诱导大鼠肝纤维化的抑制作用

目的 观察安络化纤丸对二甲基亚硝胺诱导大鼠肝纤维化形成的抑制作用.方法 采用二甲基亚硝胺诱导大鼠肝纤维化模型,观察安络化纤丸干预后大鼠肝功能、血清透明质酸(HA)和肝组织羟脯胺酸含量变化,并观察肝组织病理学改变和基质金属蛋白酶2(MMP-2)的表达情况.多组计量资料分析采用One way ANOVA,多重比较采用LSD方法.结果 安络化纤丸干预组血清ALT、AST水平分别为(129.08±53.45)U/L和(321.25±138.32)U/L,血清HA和肝组织羟脯胺酸含量分别为(1644.47±380.45)ng/ml和(0.23±0.08)μg/mg,均明显低于模型组[分别为(611.77±354.17)U/L,(1199.00±763.54)U/L,(3768.38±851.98)ng/ml,(0.51±0.13)μg/mg],差异均具有统计学意义(P<0.01).光镜下显示安络化纤丸干预组大鼠肝组织病理改变较模型组明显减轻(P<0.01),肝组织MMP-2表达强度明显高于模型组(P<0.05).结论 安络化纤丸对二甲基亚硝胺诱导的大鼠肝纤维化形成有较好的抑制作用,其可能的机制与保肝降酶、增强肝组织MMP-2活性和促进细胞外基质降解有关.     

罗格列酮影响肝纤维化大鼠转化生长因子β1(TGF-β1)表达的机制

目的探讨罗格列酮对大鼠肝纤维化的保护作用和对转化生长因子β1（TGF-β1）mRNA表达影响的机制。方法检测肝组织病理学改变；生化法检测肝功能指标；免疫组织化学技术检测TGF-β1、PPARγ在肝内的表达及定位；采用RT-PCR检测肝组织TGF-β1、PPAR-γ mRNA的表达。结果与模型组大鼠比较，干预组肝组织结构变化明显改善，纤维化增生程度减低，肝功能改善，大鼠肝内TGF-β1表达有所降低，并且大剂量组干预效果最为显著。结论罗格列酮能有效减轻肝纤维化大鼠的肝脏损伤及纤维化程度，其机制可能与PPAR-γ直接或间接抑制肝内TGF-β1 mRNA的表达有关。     

坎地沙坦对肝纤维化大鼠Ang-(1-7)的影响

目的研究血管紧张素Ⅱ1型受体拮抗剂坎地沙坦抗大鼠肝纤维化的疗效及对血管紧张素1-7[Ang-(1-7)]的影响。方法制备四氯化碳诱导大鼠肝纤维化模型,同时应用坎地沙坦灌胃,共8周。肝组织进行常规HE与Masson三色染色,并测定门脉压及血清肝功能,血浆中Ang-(1-7)应用酶联免疫方法检测。结果与模型组大鼠比较,坎地沙坦可改善肝纤维化程度及降低门脉压,血浆Ang-(1-7)水平增加。结论坎地沙坦抗肝纤维化可能与升高Ang-(1-7)有关。     

缬沙坦对免疫性大鼠肝纤维化的影响

目的研究血管紧张素Ⅰ型(AT1)受体阻断剂对免疫性大鼠肝纤维化的影响。方法采用猪血清诱导建立肝纤维化模型,以大剂量和普通剂量缬沙坦干预,观察肝组织纤维化程度、胶原表达变化;免疫组化染色观察α平滑肌肌动蛋白(αSMA)、转化生长因子β1(TGFβ1)及核因子(NF)κBp65表达情况。结果与模型组比较,治疗组胶原面积显著减少,具有剂量依赖性(P<0.05),纤维化程度也明显改善;模型组αSMA、TGFβ1、NFκBp65表达增强(P<0.05),缬沙坦治疗后,都有不同程度的减弱,模型组和大剂量组αSMA分别为19.68±1.28和8.66±1.72,TGFβ1分别为22.36±4.77和9.95±2.28,NFκBp65分别为30.31±4.16和19.80±1.96(均为面密度值,P<0.05)。结论缬沙坦能明显抑制猪血清诱导的大鼠肝纤维化发生,可能与抑制肝星状细胞活化、增殖,降低TGFβ、NFκBp65等表达有关。     

Effects of perindopril and valsartan on expression of transforming growth factor-beta-Smads in experimental hepatic fibrosis in rats

BACKGROUND: Previous studies have shown that the renin-angiotensin system (RAS) plays an important role in the pathogenesis of hepatic fibrosis, and blockers of the RAS may be active as an antifibrogenic goal. However, the potential role of RAS inhibition on expression transforming growth factor (TGF)-beta-Smads in hepatic fibrosis remains unknown. The aim of this study was to investigate the effect and mechanism of an angiotensin-converting enzyme inhibitor (perindopril) and an angiotensin II receptor blocker (valsartan) on TGF-beta1 and TGF receptor II (TRII) mRNA, Smad3 and Smad7 in fibrotic hepatic livers in rats. METHODS: Sixty Wistar rats were randomly divided into four study groups (n = 15 for each group), including normal controls, hepatic fibrosis models, and two treated groups with either perindopril or valsartan, starting from the fourth week after being exposed to carbon tetrachloride (CCl(4)) for 4 weeks. The levels of TGF-beta and TRII mRNA in liver tissue were analyzed by RT-PCR. The expressions of TGF-beta1, Smad3 and Smad7 in liver tissues were evaluated by immunohistochemistry. The liver histopathology was examined by hematoxylin and eosin (HE) staining and by electron microscopy, respectively. The liver function and serum hyaluronic acid were also assayed by biochemistry and radioimmunoassay. RESULTS: Compared with the hepatic fibrosis models, the levels of TGF-beta1, TRII mRNA and the expression Smad3 significantly decreased in the two treated groups, and the expression of Smad7 was significantly increased in the liver of rats treated with perindopril or valsartan (P < 0.05 or P < 0.01). The histological changes and ultrastructure of fibrotic liver, liver function and hyaluronic acid also remarkably improved in the treated rats. CONCLUSIONS: The angiotensin-converting enzyme inhibitors perindopril and valsartan have a protective effect on liver injury and can ameliorate hepatic fibrosis in rats induced by CCl(4). The mechanisms may be associated with their effects of down-regulating TGF-beta1, TRII mRNA and smad3, and up-regulating Smad7.     

替米沙坦对肝纤维化大鼠肝组织病理学变化的影响

目的观察替米沙坦对四氯化碳（CCl4）诱导的大鼠实验性肝纤维化模型肝组织病理学变化的影响。方法 SD大鼠40只被随机分成正常对照组（12只）、模型组（12只）和替米沙坦防治组（16只）。在制备大鼠肝纤维化动物模型成功后,取肝、脾,常规进行组织病理学检查。结果模型组大鼠平均肝指数为4.85±0.42（P〈0.05）,正常对照组为2.92±0.41,而药物干预组为3.09±0.36;模型组大鼠肝炎症活动度平均计分为18.6±2.1（P〈0.05）,正常对照组为0.0±0.0,替米沙坦干预组为8.6±1.9;模型组大鼠肝纤维化计分平均为14.5±1.6,正常对照组为0.33±0.49,替米沙坦干预组为7.7±1.7（P〈0.01）。结论替米沙坦可改善实验性纤维化大鼠肝组织病理学损伤。     

芪苓益肝颗粒对大鼠肝纤维化的治疗作用

目的:观察芪苓益肝颗粒对复合因素致大鼠肝纤维化的治疗作用。方法:采用CCl4(四氯化碳)腹腔注射联合BSA(牛血清白蛋白)皮下注射5周,制备大鼠肝纤维化模型。治疗组大鼠以芪苓益肝颗粒高、中、低3种剂量灌胃给药,分别于5、9周末观察其肝纤维化指标及肝组织病理和纤维化分期变化。结果:5周末,与模型组比较,高剂量治疗组大鼠CⅣ(Ⅳ型胶原)明显降低(P0.05),高、中、低剂量治疗组大鼠LN(层粘蛋白)、HA(透明质酸)均显著降低(P0.01或P0.05);病理组织学观察显示:与模型组比较,高剂量治疗组大鼠肝纤维化分期差异有显著性意义(P0.01)。9周末,与模型组比较,低剂量治疗组大鼠PCⅢ(Ⅲ型前胶原)显著降低(P0.01),LN、HA明显降低(P0.05),高、中、低剂量治疗组大鼠CⅣ明显降低(P0.05);病理组织学观察显示:与模型组比较,高剂量治疗组大鼠肝纤维化分期差异有显著性意义(P0.05)。结论:芪苓益肝颗粒对CCl4联合BSA所致的大鼠肝纤维化有明显的干预和治疗作用。     

Effects of vitamin E deficiency on bleomycin-induced pulmonary fibrosis in the hamster

The effects of vitamin E deficiency on bleomycin (BLM)-induced pulmonary fibrosis have been studied by analyses of pressure volume (PV) curves and morphological examinations. Golden hamsters were divided into groups on a control diet (group C), vitamin E-deficient diet (E), control diet with BLM treatment (CB), and vitamin E-deficient diet with BLM treatment (EB). Group EB showed PV curves shifted downward and to the right soon after BLM administration (10 days) and gradually shifted upward and to the left compared to group CB in the later period (30 and 60 days after BLM treatment). Histologically group EB was characterized by relatively severe interstitial pneumonitis in the early stages. In later stages, emphysematous changes were induced in combination with a lesser degree of fibrosis in group EB. Mean thickness of the alveolar wall of group CB was larger than group C while that of group EB was smaller at 30 days after BLM treatment. These results indicate that, with BLM treatment, vitamin E-deficient hamsters show increased distensibility on the PV curve and emphysematous changes mixed with focal fibrosis on morphological examination. This means that by adding other modulating factors, such as vitamin E deficiency, BLM, an agent known to produce pulmonary fibrosis, acts to induce an emphysematous lesion in the lung. Although pulmonary fibrosis and emphysema have been considered to be final and different forms of parenchymal injury, each may proceed to the other under the influence of some modulating factors.     

Effects of vitamin E deficiency on bleomycin-induced pulmonary fibrosis in hamsters]

We examined the effect of free radicals on lung defense mechanism in bleomycin (BLM)-induced pulmonary fibrosis in hamsters. The concentration of vitamin E (VE) in the lung tissue increased significantly after intratracheal BLM administration. VE deficient hamsters showed increased lipid peroxide values in the lung tissue at a very early stage after BLM treatment. This was followed by decreased superoxide dismutase activities in the lung tissue. The results indicate that; 1) VE appears to be necessary for the prevention of lipid peroxidation in BLM-induced oxidant lung injury, 2) VE deficiency produces a large number of free radicals at the early stage after BLM treatment, and might induce protease-antiprotease imbalance within the lung, which probably causes an emphysematous change in the BLM-treated lung at a late stage after BLM administration.     

Effects of vitamin E deficiency on bleomycin-induced pulmonary fibrosis in the hamster

The effects of vitamin E deficiency on bleomycin (BLM)-induced pulmonary fibrosis have been studied by analyses of pressure volume (PV) curves and morphological examinations. Golden hamsters were divided into groups on a control diet (group C), vitamin E-deficient diet (E), control diet with BLM treatment (CB), and vitamin E-deficient diet with BLM treatment (EB). Group EB showed PV curves shifted downward and to the right soon after BLM administration (10 days) and gradually shifted upward and to the left compared to group CB in the later period (30 and 60 days after BLM treatment). Histologically group EB was characterized by relatively severe interstitial pneumonitis in the early stages. In later stages, emphysematous changes were induced in combination with a lesser degree of fibrosis in group EB. Mean thickness of the alveolar wall of group CB was larger than group C while that of group EB was smaller at 30 days after BLM treatment. These results indicate that, with BLM treatment, vitamin E-deficient hamsters show increased distensibility on the PV curve and emphysematous changes mixed with focal fibrosis on morphological examination. This means that by adding other modulating factors, such as vitamin E deficiency, BLM, an agent known to produce pulmonary fibrosis, acts to induce an emphysematous lesion in the lung. Although pulmonary fibrosis and emphysema have been considered to be final and different forms of parenchymal injury, each may proceed to the other under the influence of some modulating factors.