缬沙坦治疗原发性高血压对内源性纤溶活性的影响

目的 :观察缬沙坦治疗原发性高血压 (EH)的同时对内源性纤溶活性的影响。方法 :用发色底物分解显色法测定 6 4例EH患者 (EH组 )和 35例正常对照者 (对照组 )的组织型纤溶酶原激活因子 (t PA)、纤溶酶原激活抑制物 (PAI 1)的活性 ,然后EH组口服缬沙坦 80mg ,每日 1次 ,共 8周 ,比较治疗前后的t PA和PAI 1活性变化。结果 :EH组治疗前t PA活性较对照组明显降低 ,PAI 1活性明显升高 (P <0 .0 5 )。经缬沙坦治疗 8周后 ,t PA活性较治疗前显著上升 ,PAI 1活性降低 (P <0 .0 5 )。结论 :缬沙坦在降低血压的同时 ,有改善内源性纤溶活性的作用。     

血管紧张素Ⅱ和血管紧张素1-7对内皮细胞释放组织纤溶酶原激活物及其抑制剂-1的影响

目的 :研究血管紧张素Ⅱ (AngⅡ )和血管紧张素 1 7[Ang ( 1 7) ]对内皮细胞分泌组织纤溶酶原激活物 (t PA)和纤溶酶原激活物抑制剂 1(PAI 1)的影响。方法 :培养内皮细胞株 (ECV30 4 ) ,分为AngⅡ和Ang ( 1 7)刺激组 ,培养基中AngⅡ和Ang ( 1 7)加至终浓度为 5、10、2 5、5 0、10 0nmol/L ,2 4h后测定上清液中的t PA和PAI 1的含量。结果 :内皮细胞在AngⅡ终浓度为 5 0、10 0nmol/L组刺激 2 4h后 ,其分泌的PAI 1含量较对照组有明显升高 ,差异有统计学意义 (P <0 .0 5 )。而Ang ( 1 7)在同样浓度组却显著降低PAI 1(P <0 .0 5 ) ,AngⅡ和Ang ( 1 7)两组t PA含量差异无统计学意义 ( P >0 .0 5 )。结论 :AngⅡ对内皮细胞株分泌的PAI 1有显著的升高作用 ,而Ang ( 1 7)对PAI 1作用相反。两者对t PA均无显著影响。提示AngⅡ和Ang ( 1 7)对纤溶系统的调节有一定作用     

缺血性脑血管病纤溶活性和血清同型半胱氨酸含量测定的临床意义

目的　探讨缺血性脑血管病 (ICVD)患者血浆纤溶活性和血清同型半胱氨酸 (Hcy)含量的变化及其临床意义。方法　入选ICVD患者 86例 (ICVD组 ) ,根据病情又分为短暂脑缺血发作 (TIA)组 14例 ,脑梗死组 72例 ,并入选非脑血管病患者 4 3例作为对照组 ,分别采用产色法测定血浆纤溶酶原 (Plg)、组织型纤溶酶原激活物 (t PA)、纤溶酶原激活抑制物 1(PAI 1)活性 ,荧光偏振光法测定血清Hcy,电化学发光法测定叶酸 ,同时常规测定血脂水平。结果　ICVD组 ,TIA患者和脑梗死患者血浆Plg、t PA活性均较对照组显著降低 (P <0 .0 5 )。ICVD组血清Hcy水平较对照组明显升高 (P <0 .0 1) ,t PA活性降低和高Hcy对ICVD的发生均有显著作用。结论　t PA活性降低和高Hcy分别是ICVD的独立危险因素     

体外治疗性超声对大鼠纤溶系统的影响

目的　研究体外治疗性超声对大鼠血浆组织型纤溶酶原激活因子 (t-PA)、纤溶酶原激活物抑制因子 -1(PAI -1)的影响。方法　采用酶联免疫吸附法测定超声治疗前后大鼠血浆t-PA、PAI -1的改变。结果　超声治疗后ETUS组t-PA(0 .5 4± 0 .19)IU/ml,PAI -1(0 .44± 0 .18)AU/ml,对照组t -PA(0 .5 1± 0 .2 5 )IU/ml,PAI -1(0 .43± 0 .19)AU/ml,二者比较无明显差异 (P >0 .0 5 )。结论　治疗剂量超声对大鼠纤溶系统没有影响     

纤溶酶原激活物抑制物-1基因转导对肾小球系膜细胞外基质积聚的影响

目的　利用体外基因转染技术使纤溶酶原激活物抑制物 1(PAI 1)基因过表达 ,直接观察局部PAI 1对大鼠系膜细胞外基质 (ECM)积聚的影响 ,解析ECM积聚的分子机制。方法　以绿色荧光蛋白 (GFP)为报告基因 ,构建PAI 1/GFP融合基因真核表达载体 ,利用脂质体将外源PAI 1cDNA导入体外培养的大鼠系膜细胞。在活细胞状态下 ,动态观察外源基因的表达。用Northern杂交、ELISA方法检测大鼠系膜细胞纤维连接蛋白 (FN)、层连蛋白 (LN)及IV型胶原表达。结果　PAI 1基因转染后 ,转染组大鼠系膜细胞中的培养上清PAI活性明显增高 ,到 2 4小时达最高值 ( 8.16± 0 .62 )IU/ml,与对照组 ( 2 .2 7± 0 .19)IU/ml相比 ,差异有显著性 (P <0 .0 5 )。同时基因转染组FN( 0 .5 1±0 0 3 )、LN( 1.2 6± 0 .0 7)及Ⅳ型胶原 ( 0 .98± 0 .0 8)水平均较对照组明显增高 (P <0 .0 5 )。结论　首次建立了系膜细胞PAI 1的过度表达体系 ,证实细胞过度表达PAI 1可以直接导致ECM的积聚。局部PA/PAI活性的变化可能是调节系膜细胞ECM积聚与降解的重要因素。     

缺血性脑血管病患者血脂、凝血及纤溶指标的变化

目的　观察缺血性脑血管病 (ICVD)患者血脂、凝血及纤溶指标的变化。方法　对缺血性脑血管病 113例 [包括脑梗死 (CI)急性期 2 5例 ,恢复期 30例 ;短暂性脑缺血发作 (TIA) 5 8例 ]和正常对照组 77名进行血脂、血浆组织型纤溶酶原激活物 (t PA)、纤溶酶原激活物抑制物 (PAI)和D 二聚体浓度进行测定。结果　CI组甘油三酯 (TG)、总胆固醇 (TC)、载脂蛋白B10 0 (ApoB10 0 )、氧化型低密度脂蛋白 (ox LDL)水平显著高于对照组 ;CI急性期、恢复期和TIA组PAI高于对照组 ,而t PA活性均低于对照组 ;TIA伴有梗死灶者血浆D 二聚体和PAI含量明显高于无梗死灶者 ,t PA含量低于无梗死灶者。结论　ICVD患者不仅存在血脂代谢紊乱 ,且体内凝血活性增强 ,纤溶功能下降。     

纤溶酶原激活物及其抑制物与肝脏疾病

纤溶酶原激活物(plasminogenactivator ,PA)主要有组织型(t-PA)和尿激酶型(u -PA)二类,由血管内皮细胞和组织细胞分泌,是一种有丝氨酸蛋白水解酶作用的单链糖蛋白,主要参与纤溶过程、细胞迁移和组织重建。纤溶酶原激活物抑制物(plasminogenactivatorinhibitor,PAI)大部分来源于     

单纯性肥胖患者低热量高蛋白饮食减肥对纤溶活性影响的研究

目的　观察低热量高蛋白饮食减肥对单纯性肥胖患者血纤溶系统活性的影响。方法　武警广东总队医院2000-10~2001-01采用自身对照的研究方法,对30例单纯性肥胖患者给予低热量高蛋白饮食治疗12周。治疗前后测定组织型纤溶酶原抑制物(PAI- 1Ag)及活性、纤溶酶原激活物(t- PA)和纤维蛋白原(FIB)。结果　经过12周的治疗,平均减轻体重4 .72 ,体重指数(BMI)、腰围和腰臀围比明显下降;随着体重的下降,血清空腹胰岛素(FINS)、甘油三酯(TG)、总胆固醇(TC)、血浆PAI 1Ag及活性、t-- PA明显降低,而空腹血浆血糖(FPG)和FIB无明显变化;PAI -1Ag、t -PA与BMI、腰围和FINS等呈正相关;多元逐步回归分析显示ΔFINS和Δ体重为ΔPAI- 1Ag的独立影响因素。结论　低热量高蛋白饮食减肥可增加单纯性肥胖患者的纤溶活性,PAI- 1Ag的降低主要是由于体重的减轻。     

老年人不稳定型心绞痛与稳定型心绞痛TF、tPA和PAI-1检测的临床意义

目的　观察老年人 (≥ 60岁 )不稳定型心绞痛 ( U A)和稳定型心绞痛 ( SA)患者体内组织因子 ( TF)、组织型纤溶酶原激活物( t PA)、组织型纤溶酶原激活物抑制物 -1( PAI-1)的变化。方法　采用 ELISA双夹心法。结果　不稳定型心绞痛组血浆 TF水平高于稳定型心绞痛组和对照组 ,稳定型心绞痛组高于对照组。不稳定型心绞痛组与稳定型心绞痛组和对照组对比 ,血浆 t PA活性、t PA/PAI-1明显降低 ,PAI-1活性明显增高 (均为 P<0 .0 5 )。结论　冠心病患者存在凝血纤溶系统失平衡 ,可能对老年人不同类型冠心病的发生发展起重要作用。     

慢性心力衰竭患者内皮功能和纤溶功能的研究

慢性心力衰竭(CHF)是各种心血管疾病发展的终末阶段,有很高的致残率。临床研究表明,CHF患者血液呈高凝状态,并与CHF严重程度有关〔1〕,有发生血栓栓塞的倾向,但其形成血栓的机制尚未完全阐明。本研究通过观察CHF患者血浆血管性血友病因子(vWF)、纤溶酶原激活物抑制物1 (PAI 1 )、组织型纤溶酶原激活物(t PA)抗原水平的变化,旨在探讨CHF患者内皮细胞功能和纤溶功能的变化及意义。1 　对象与方法1 .1 　对象本院收治CHF患者60例,其中男33例,女2 7例,年龄1 5～5 8( 4 0 .37±9.98)岁。CHF的诊断依据国内外通用的诊断标准,心功能Ⅱ…     

uPA纤溶途径与肝纤维化

细胞外基质(extracellular matrix,ECM)过度沉积是肝纤维化的特征性表现,纤溶系统尤其是尿激酶型纤溶酶原激活剂(urokinase- plasminogen activator,uPA)所介导的纤溶途径与肝纤维化关系密切,其主要成分包括纤溶酶原、纤溶酶、纤溶酶原激活剂及其抑制剂．uPA纤溶途径位于ECM降解酶系的顶端,肝纤维化时通过uPA-纤溶酶-基质金属蛋白酶(matrix metalloproteinases,MMPs)-ECM级联机制下调ECM降解,促进ECM在肝内沉积,而且可能在肝星状细胞(hepatic stellate cell,HSC)增殖、迁移以及肝细胞再生等过程中起到重要作用．     

尿激酶型纤溶酶原激活物及其抑制物与肝纤维化

肝纤维化是肝脏对慢性损伤的一种修复反应,以细胞外基质(ECM)在肝内过多沉积为特征。尿激酶型纤溶酶原激活物(uPA)及其抑制物(PAI)是调节基质金属蛋白酶(MMP)活性和ECM降解的关键因素。uPA通过uPA-纤溶酶-MMP级联反应途径,最终可产生活化的纤溶酶和MMP,后两者是降解ECM的重要物质。因而调控uPA的表达,可能为肝纤维化的治疗提供新的途径。     

Production and release of plasminogen by isolated perfused rat liver.

In view of conflicting evidence for a major hepatic role in the synthesis of circulating plasminogen, the precursor of the fibrinolytic enzyme plasmin, we carried out the present study with a sensitive assay in order to measure the accumulation of small quantities of plasminogen in a recycling rat liver perfusion system. We have purified plasminogen from Sprague-Dawley rat plasma and have raised a monospecific antiserum against it in rabbits. Isolated rat liver perfusions were performed with an oxygenated recycling perfusate consisting of a perfluorotributylamine/Pluronic F-68 emulsion (Fluosol 43) free of plasma proteins and blood cells. The system was shown to be capable of synthesizing albumin and transferrin. The cumulative appearance of plasminogen in the perfusate was measured by a sensitive, specific radioimmunoassay. Plasminogen concentration increased progressively during the first 2 hr of perfusion; the observed average net synthesis in five separate experiments was approximately 35 microgram/hr per 100 g of body weight. Exposure of the perfused liver to 18 microM cycloheximide inhibited additional increase in the titer of plasminogen. Evidence for de novo synthesis was provided by the incorporation of 14C-labeled leucine into specific immunoprecipitates of plasminogen and the inhibition of this incorporation by cycloheximide. Analysis of the immunoprecipitates by sodium dodecyl sulfate/polyacrylamide gel electrophoresis revealed a single peak of radioactivity corresponding to Mr of 82,000. These data indicate that the liver is a major site of plasminogen production.     

Disruption of tissue-type plasminogen activator gene in mice aggravated liver fibrosis

Background and Aim:  Tissue-type plasminogen activator (tPA) is one of the major components in the matrix proteolytic network whose role in the pathogenesis of liver fibrosis remains unknown. The aim of this study is to investigate the role of tPA in carbon tetrachloride (CCl₄)-induced liver fibrosis.
Methods:  Wild-type and tPA knockout mice (8 mice per group) were injected interperitoneumly with 25% CCl₄ 2 ml/kg twice per week as CCl₄ administration groups and olive oil 2 ml/kg as controls. After 4 weeks, the livers of mice were removed under deep anesthesia and prepared for further studies such as histology, immunostaining, hydroxyproline assay, zymography and western blot analysis.
Results:  Mice lacking tPA developed more severe morphological injury and displayed an increased deposition of collagen in the liver after CCl₄ administration compared with wild-type counterparts. Deficiency of tPA increased α-smooth muscle actin expression in the mice livers. On the other hand, the decrease of matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9) activities, metalloproteinase-13 (MMP-13) expression and a marked increase of tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) expression were found in the liver of CCl₄ administrated tPA^−/− mice compared with wild-type counterparts.
Conclusions:  Deficiency of tPA aggravated liver fibrosis through promoting hepatic stellate cells (HSCs) activation and inhibiting ECM degradation by decreasing MMP-2, MMP-9 activities and disrupting the balance between MMP-13 and TIMP-1.     

Tissue-type plasminogen activator deficiency exacerbates cholestatic liver injury in mice

Recent studies demonstrating a role for plasminogen activator inhibitor (PAI)-1 in cholestatic liver disease in mice suggested that tissue-type plasminogen activator (tPA) or urokinase plasminogen activator (uPA) might be important after biliary tract obstruction. We now demonstrate that blocking tPA exacerbates liver injury after bile duct ligation (BDL). tPA deficient mice have increased bile infarcts, increased TUNEL positive cells, increased neutrophil infiltration, reduced hepatocyte proliferation and reduced ductular reaction 72 hours after BDL compared to wild type mice. In addition, the protective and proliferative effects of plasminogen activator inhibitor 1 (PAI-1) deficiency after BDL are dramatically blocked by the tPA inhibitor tPA-STOP. One potential mechanism for these effects is that both tPA deficiency and tPA-STOP reduce hepatocyte growth factor (HGF) activation and c-Met phosphorylation in the liver after BDL. In support of this hypothesis, HGF treatment reverses the effects of tPA deficiency in mice. Furthermore, preferential tPA activation in areas of injury after BDL might occur because fibrin accumulates in bile infarcts and activates tPA. CONCLUSION: tPA inactivation accelerates liver injury after BDL and reduces HGF activation. These data suggest that strategies to increase HGF activation might be protective in liver diseases with biliary tract obstruction even without increased HGF production.     

Urokinase-type plasminogen activator supports liver repair independent of its cellular receptor

Background  

The urokinase-type (uPA) and tissue-type (tPA) plasminogen activators regulate liver matrix remodelling through the conversion of plasminogen (Plg) to the active protease plasmin. Based on the efficient activation of plasminogen when uPA is bound to its receptor (uPAR) and on the role of uPA in plasmin-mediated liver repair, we hypothesized that uPA requires uPAR for efficient liver repair.     

Increased expression of plasminogen activator and plasminogen activator inhibitor during liver fibrogenesis of rats: role of stellate cells.

BACKGROUND/AIMS: Plasminogen activators and plasminogen activator inhibitors are important regulators of the balance between the proteolytic and antiproteolytic activities that determine extracellular matrix turnover. We examined the expression of plasminogen activator-plasmin system components in experimental liver fibrosis of rats. METHODS: Liver fibrosis was produced in rats by injecting carbon tetrachloride for 6 to 12 weeks. Gene expression for plasminogen activator inhibitor-1 (PAI-1), urokinase and tissue plasminogen activators (uPA and tPA), urokinase plasminogen activator receptor (uPAR), and transforming growth factor-beta1 (TGF-beta1) was examined by Northern analysis. Western analysis was performed to detect protein expression of PAI-1, uPA and uPAR. An immunohistochemical study was performed to detect the localization of PAI-1. Additionally, primary cultured liver cells were examined by Northern and Western analyses for this protein with or without prior incubation with TGF-beta1. RESULTS: At 6 weeks, when fibrosis had occurred, uPA and uPAR mRNAs had increased 2.8-fold and 1.8-fold, respectively; PAI-1 and tPA mRNA levels were unchanged. At the cirrhotic stage (9 to 12 weeks), mRNA levels for PAI-1, uPA, uPAR and tPA were all increased. Western analysis also showed increased uPA and uPAR expressions in fibrotic liver, and increased PAI-1, uPA and uPAR expressions in cirrhotic liver. PAI-1 protein was also demonstrated immunohistochemically along sinusoids, vessels, and bile duct cells of normal and fibrotic liver. In liver cell cultures, Kupffer cells, hepatocytes, and especially stellate cells, expressed PAI-1. Expression was enhanced in stellate cells cultured from fibrotic or cirrhotic liver or stimulated in vitro with TGF-beta1. CONCLUSION: Though increased uPA and uPAR may act on matrix degradation in fibrotic liver, increased PAI-1 together with uPA, uPAR and tPA are associated with overall inhibition of matrix degradation in cirrhotic liver. Hepatic stellate cells are an important source of PAI-1 during liver fibrosis.     

肝硬化患者血浆中尿激酶型纤溶酶激活物的检测及其意义

目的 探讨肝硬化患者血浆尿激酶型纤溶酶激活物(uPA)、尿激酶型纤溶酶激活物受体(uPAR)、纤溶酶原激活物抑制剂-1(PAI-1)的变化及其意义。 方法 确诊的72例乙型肝炎后肝硬化患者,Child-pugh分级A级23例(A组),B级29例(B组),C级20例(C组)。6例健康志愿献血者为正常对照组。酶联免疫吸附实验测定血浆uPA、uPAR、PAI-1的变化。并同时检测血透明质酸(HA)、Ⅳ型胶原(C Ⅳ)、Ⅲ型前胶原(PC Ⅲ)、血浆白蛋白、胆红素、凝血酶原时间及其活动度改变。 结果 随着肝硬化的进展,血浆uPA、uPAR、PAI-1逐渐增加,HA、PC Ⅲ也明显增加。Child C组患者血浆uPA、uPAR、PAI-1水平(μg/L)分别为1.88±0.64、4.82±2.02和52.60±16.87,A组分别为1.36±0.43、3.03±1.48和24.09±7.14,B组分别为1.79±0.62、4.80±2.22和41.40±17.52,C组与A、B组比较,t值为2.81～7.38,P值均<0.01。A组血浆uPA与PC Ⅲ呈负相关(r=-0.4785,P<0.05);C组PAI-1与HA呈正相关(r=0.5447,P<0.01)。 结论 肝硬化晚期,虽然血浆uPA、PAI-1增加,但总的效应表现为uPA相对不足,肝基质纤维降解受抑制,血浆uPA、PAI-1与肝硬化发展密切相关。     

纤溶酶原激活物抑制物在纤维化肝组织中的表达及其血浆活性检测

目的 研究和探讨纤溶酶原激活物抑制物（ｐｌａｓｍｉｎｏｇｅｎ ａｃｔｉｖａｔｏｒ ｉｎｈｉｂｉｔｏｒ－１,ＰＡＩ－１）在人肝纤维化组织中分布、作用及血浆中活性水平的变化。方法 采用原位杂交和免疫组织化学方法检测正常人,慢性乙型肝炎及肝硬化患者肝组织中ＰＡＩ－１ｍＲＮＡ和蛋白表达,并对蛋白表达的半定量结果与肝纤维化程度进行对比分析。同时采用发色７底物法检测血浆中ＰＡＩ－１活性。结果 随肝纤维化程度的