Tissue factor pathway inhibitor and bacterial infection

See also van den Boogaard FE, Brands X, Schultz MJ, Levi M, Roelofs JJTH, van ‘t Veer C, van der Poll T. Recombinant human tissue factor pathway inhibitor exerts anticoagulant, anti‐inflammatory and antimicrobial effects in murine pneumococcal pneumonia. This issue, pp 122–32.     

Tissue factor pathway inhibitor is an inhibitor of factor VII‐activating protease

Background:  Factor VII‐activating protease (FSAP) is a serine protease that circulates in plasma in its inactive single‐chain form and can be activated upon contact with dead cells. When activated by apoptotic cells, FSAP leads to the release of nucleosomes. The serpins C1‐inhibitor and α₂‐antiplasmin are reported to be the major inhibitors of FSAP. However, regulation of FSAP activity by Kunitz‐type inhibitors is not well studied. Objectives:  To compare the inhibition of FSAP activity and FSAP‐induced nucleosome release from apoptotic cells by tissue factor pathway inhibitor (TFPI) with that of C1‐inhibitor and α₂‐antiplasmin. Methods:  Apoptotic cells were incubated with plasma or FSAP in presence of the inhibitor, and nucleosome release was analyzed with flow cytometry. Monoclonal antibodies against TFPI and altered forms of TFPI were used to investigate which domains of TFPI contribute to FSAP inhibition. Results and Conclusions:  We show that TFPI abrogates FSAP activity and nucleosome release from apoptotic cells. TFPI is a much more efficient inhibitor than C1‐inhibitor or α₂‐antiplasmin. The active site of K2 is required for inhibition of FSAP. A direct binding interaction between FSAP and the C‐terminal domain of TFPI is also required for efficient inhibition. Inhibition of FSAP‐induced nucleosome release by recombinant TFPI might, in part, explain the anti‐inflammatory effects of recombinant TFPI infusion observed in animal and human sepsis.     

胃癌患者基质金属蛋白酶组织抑制因子2的表达与其临床检测的意义

目的探讨在正常胃黏膜组织、胃癌组织及胃区域淋巴结中基质金属蛋白酶组织抑制因子2(TIMP-2)的表达情况。方法选取经病理证实的胃癌标本96例,胃癌区域淋巴结96例,正常胃黏膜60例,全部病例均随访5年以上。采用免疫组织化学方法的链霉菌抗生物素蛋白-过氧化物酶连接(SP)法检测上述标本中TIMP-2的表达。结果各病理因素TIMP-2表达阳性率:高中度分化与低分化69.0%vs 18.4%(P<0.01);浸润深度T1+T2与T3+T465.9%vs 36.4%(P<0.01);临床分期Ⅰ～Ⅱ型比Ⅲ～Ⅳ型71.1%vs 34.5%(P<0.01);无淋巴结转移与有淋巴结转移64.3%vs 37.0%(P<0.01);生存期≥5年与<5年73.0%vs 33.9%(P<0.01)。结论胃癌组织中TIMP-2表达的下降在胃癌的侵袭转移及预后中发挥着重要的作用。TIMP-2的表达对预测胃癌侵袭转移、评估患者预后状况及合理指导胃癌的综合治疗等具有重要的临床意义。     

Tissue factor pathway inhibitor and antithrombin trial results

The endogenous plasma anticoagulant proteins tissue factor pathway inhibitor (TFPI) and antithrombin (AT) have both been extensively studied in large, multinational phase III clinical trials in patients with severe sepsis. The TFPI and AT trials failed to result in significant reductions in the 28-day, all-cause mortality rates in their respective study populations. However, there appear to be definable patient populations within each study that may have benefited from TFPI or AT. Drug-drug interactions and dosing issues were observed in both trials. The similarities and differences of each anticoagulant and the lessons learned from the recent phase III clinical trials are examined in this review.     

角膜基质细胞基质金属蛋白酶1，2活性与组织因子途径抑制物2的效应

背景：有研究表明,基质金属蛋白酶所参与的细胞外基质降解在角膜新生血管形成过程中起关键作用,组织因子途径抑制物2是新近发现的一种新型的丝氨酸蛋白酶抑制物,能有效抑制基质金属蛋白酶的活性。 目的：观察组织因子途径抑制物2对体外角膜基质细胞表达基质金属蛋白酶活性的关系。 方法：在体外对兔角膜基质细胞进行原代及传代培养,用脂质体介导的人类组织因子途径抑制物2真核表达载体转染兔角膜基质细胞,G418筛选阳性细胞。 结果与结论：RT-PCR,Western blot及明胶酶谱法分析结果显示,转染后角膜基质细胞组织因子途径抑制物2 mRNA和蛋白质的表达均上调（P 〈 0.05）,而基质金属蛋白酶1,2的活性下降（P 〈 0.05）。结果提示,组织因子途径抑制物2可明显抑制角膜基质细胞中基质金属蛋白酶1,2的活性。     

Tissue factor pathway inhibitor as a universal anticoagulant for use in clinical laboratory tests.

Tissue factor pathway inhibitor (TFPI) is a protease inhibitor of extrinsic coagulation. The present study investigates the possibility of utilizing TFPI as a universal anticoagulant in clinical laboratory tests. The optimal concentration of TFPI for use in clinical laboratory tests was found to be 1 microl TFPI/ml blood (100 mmol TFPI/ml blood); the subsequent analyses were conducted at this concentration. In hematological tests, complete blood cell count and differential white blood cell count were done with an automatic blood analyzer. The results except for platelet and white blood cell counts were similar for ethylenediaminetetraacetic acid (EDTA)-treated and TFPI-treated samples. The effects of TFPI on platelet count were more pronounced when blood samples were stored at 4 degrees C than at room temperature. The effects of TFPI on cell morphology were evaluated by spreading blood samples into thin films and applying a Giemsa stain. The results showed that TFPI did not alter the morphology of blood cells. An automatic biochemical analyzer performed seventeen basic biochemical tests on serum samples and TFPI-treated plasma samples. The results of seventeen tests were comparable between TFPI-treated samples and EDTA-treated samples. The prothrombin time for TFPI-treated plasma samples was longer than that for citrated plasma samples. Nonetheless, in activated partial thromboplastin time tests, the addition of the reagent caused turbidity and partial coagulation, thus demonstrating that TFPI is not suitable for this assay. These findings suggest that although some tests cannot be performed with TFPI, this compound may be useful as a universal anticoagulant in the future.     

Tissue factor pathway inhibitor-γ is an active alternatively spliced form of tissue factor pathway inhibitor present in mice but not in humans

Summary.  Background:  Tissue factor pathway inhibitor (TFPI) is a potent inhibitor of tissue factor procoagulant activity produced as two alternatively spliced isoforms, TFPIα and TFPIβ, which differ in domain structure and mechanism for cell surface association. 3' Rapid amplification of cDNA ends was used to search for new TFPI isoforms. TFPIγ, a new alternatively spliced form of TFPI, was identified and characterized. Methods:  The tissue expression, cell surface association and anticoagulant activity of TFPIγ were characterized and compared to those of TFPIα and TFPIβ through studies of mouse and human tissues and expression of recombinant proteins in Chinese hamster ovary (CHO) cells. Results:  TFPIγ is produced by alternative splicing using the same 5'-splice donor site as TFPIβ and a 3'-splice acceptor site 276 nucleotides beyond the stop codon of TFPIβ in exon 8. The resulting protein has the first two Kunitz domains connected to an 18 amino acid C-terminal region specific to TFPIγ. TFPIγ mRNA is differentially produced in mouse tissues but is not encoded within the human TFPI gene. When expressed in CHO cells, TFPIγ is secreted into conditioned media and effectively inhibits tissue factor procoagulant activity. Conclusions:  TFPIγ is a third alternatively spliced form of TFPI that is widely expressed in mouse tissues but not made by human tissues. It contains the first two Kunitz domains and is a secreted, rather than a cell surface-associated, protein. It is a functional anticoagulant and may partially explain the resistance of mice to coagulopathy in tissue factor-mediated models of disease.     

组织因子途径抑制物-2基因原核表达及其重组蛋白生物活性研究

目的构建人组织因子途径抑制物-2（TFPI-2）基因的原核表达载体并在大肠杆菌中有效表达；探索重组TFPI-2抑制纤溶酶活性及其对人卵巢癌细胞（A2780）迁徙浸润能力的影响。方法1．以TFPI-2cDNA为模板，PCR扩增得到645bpDNA片段，克隆入表达载体pET28a，并转化大肠杆菌B121株表达。2．限制性内切酶和菌落PCR法鉴定TFPI-2基因DNA片段，Western blot法鉴定TFPI-2融合蛋白。3．建立TFPI-2抑制纤溶酶的动力学方法并测定重组TFPI-2对纤溶酶的抑制作用。4．在体外用Boyden小室，以不同浓度TFPI-2作用A2780细胞进行迁徙和浸润实验。结果1．成功构建重组TFPI-2的原核表达载体pET28a并在B121株中表达、纯化，获得大量TFPI-2蛋白。2．Western blot证实表达的融合蛋白为TFPI-2。3．重组TFPI-2对液相和固相中的纤溶酶具有显著抑制作用，且呈剂量-效应关系。4．在迁徙实验中，将A2780．TFPI-2不同浓度组与A2780对照组细胞穿过人工膜的细胞数进行比较，经t检验，无统计学意义（P〉0．05）；在浸润实验中，将A2780-TFPI-2不同浓度组与A2780对照组细胞穿过人工膜的细胞数进行比较及TFPI-2不同浓度组间的细胞数进行比较，经t检验，具有显著差异（P〈0．01）。结论1．人TTPI-2基因的表达，为TFPI-2病理生理的作用和临床研究提供了丰富材料。2．重组TFPI-2抑制纤溶酶活性的研究，为探讨TFPI-2对人卵巢癌细胞浸润转移能力的影响等提供了实验依据。3．重组TFPI-2对人卵巢癌细胞体外自身运动能力无影响，但可显著抑制人卵巢癌细胞的体外浸润能力，为将来卵巢癌用蛋白酶抑制剂治疗提供一可能的靶向依据。     

基质金属蛋白酶基因多态性与原发性高血压伴颈动脉粥样病变相关性研究

目的:探讨基质金属蛋白酶(matrix metalloproteinase,MMP)与原发性高血压(essential hypertension, EH)伴颈动脉粥样硬化(carotid atherosclerosis,CAS)的关系.方法:EH患者488倒,汉族276例.维族212例,采用聚合酶链反应一限制性片断长度多态性技术测定MMPs基因多态性.依据是否存在颈动脉粥样病变分为CAS组293例和颈动脉内膜正常组(NS组)195例.检测各组血压、血脂水平,分别比较各组基因型频率及不同基因型发生EH的风险,分析EH伴CAS的可能危险因素.结果:(1)MMP-2 TT基因型,T等位基因频率和MMP-3 6A/6A基因型、6A等住基因频率在cAs组高于NS组,差异有统计学意义(P<0.05).(2)汉族MMP_2-735 CT+TT和MMP-3-1171 6A/6A联合基因型优势比增加;维族MMP-2-735 CT+TT和MMP-3-11 71 6A/6A联合基因型优势比降低.(3)回归分析显示MMP-2 C-735T基因型是维、汉族EH伴CAS的独立危险因素,MMP-3-1171 5A/6A基因型是汉族EH伴CAS的独立危险因素(P<0.05),与MMP-2具协同效应.结论:MMP一2和MMP一3在人群中的分布存在民族差异;MMP-2-735 T等住基因增加了EH患者伴发CAS的风险,MMP-3-1171 6A等位基因增加了汉族EH患者伴发CAS的风险.     

Tissue factor pathway inhibitor reduces mortality from Escherichia coli septic shock.

This study was designed to test the hypothesis that tissue factor pathway inhibitor (TFPI) plays a significant role in vivo in regulating coagulation that results from exposure of blood to tissue factor after vascular injury as in the case of gram negative sepsis. Highly purified recombinant TFPI (6 mg/kg) was administered either 30 min or 4 h after the start of a lethal intravenous Escherichia coli infusion in baboons. Early posttreatment of TFPI resulted in (a) permanent seven-day survivors (5/5) with significant improvement in quality of life, while the mean survival time for the controls (5/5) was 39.9 h (no survivors); and (b) significant attenuations of the coagulation response and various measures of cell injury, with significant reductions in pathology observed in E. coli sepsis target organs, including kidneys, adrenals, and lungs. TFPI administration did not affect the reduction in mean systemic arterial pressure, the increases in respiration and heart rate, or temperature changes associated with the bacterial infusion. TFPI treated E. coli infected baboons had significantly lower IL-6 levels than their phosphate buffered saline-treated controls, however tumor necrosis factor levels were similarly elevated in both groups. In contrast to the earlier 30-min treatment, the administration of TFPI at 4 h, i.e., 240 min, after the start of bacterial infusion resulted in prolongation of survival time, with 40% survival rate (2/5) and some attenuation of the coagulopathic response, especially in animals in which fibrinogen levels were above 10% of normal at the time of TFPI administration. Results provide evidence for the significance of tissue factor and tissue factor pathway inhibitor in bacterial sepsis, and suggest a role for blood coagulation in the regulation of the inflammatory response.     

Tissue factor production not balanced by tissue factor pathway inhibitor in sepsis promotes poor prognosis

OBJECTIVE: To determine the precise relationship among tissue factor, tissue factor pathway inhibitor (TFPI), and neutrophil elastase in sepsis, as well as to test the hypothesis that low TFPI concentrations are not sufficient to prevent tissue factor-dependent intravascular coagulation, leading to multiple organ dysfunction syndrome and death. DESIGN: Prospective, cohort study. SETTING: General intensive care unit of tertiary care emergency department. PATIENTS: Thirty-one consecutive patients with sepsis, classified as 15 survivors and 16 nonsurvivors. Ten normal, healthy volunteers served as controls. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Tissue factor antigen concentration (tissue factor), TFPI, neutrophil elastase, and global variables of coagulation and fibrinolysis were measured on the day of diagnosis of sepsis, severe sepsis, and septic shock and days on 1-4 after diagnosis. The number of systemic inflammatory response syndrome criteria that patients met and the disseminated intravascular coagulation score were determined simultaneously. The results of these measurements were compared between the survivors and the nonsurvivors. In the nonsurvivors, significantly higher concentrations of tissue factor and neutrophil elastase were found compared with the survivors and control subjects. However, the TFPI values showed no difference between the two groups. No correlation was found between the peak concentrations of tissue factor and TFPI. Disseminated intravascular coagulation scores and numbers of the SIRS criteria met by the survivors significantly decreased from day 0 to day 4, but those of the nonsurvivors did not improve during the study period. The nonsurvivors showed thrombocytopenia and higher numbers of dysfunctioning organs than did the survivors. CONCLUSIONS: We systematically elucidated the relationship between tissue factor and TFPI in patients with sepsis, severe sepsis, and septic shock. Activation of tissue factor-dependent coagulation pathway not adequately balanced by TFPI has important roles in sustaining DIC and systemic inflammatory response syndrome, and it contributes to multiple organ dysfunction syndrome and death. High concentrations of neutrophil elastase released from activated neutrophils may explain, in part, the imbalance of tissue factor and TFPI in sepsis.     

基质金属蛋白酶及其组织抑制剂与滋养细胞侵袭性生长关系的研究

目的了解基质金属蛋白酶（MMPs）和组织抑制剂（TIMPs）在滋养细胞中的定位及其在不同滋养细胞病变中的表达和相互调节作用.方法采用免疫组化方法检测MMP-2、MMP-9和TMP-1、TIMP-2在绒毛膜癌、侵袭性水泡状胎块、水泡状胎块、胎盘植入和超常反应胎盘部位等病变以及胎盘着床部位中的表达.结果MMP-2、9和TIMP-1、2主要在中间滋养细胞和合体滋养细胞表达.滋养细胞在胎盘着床部位仅表达MMP-2;超常反应胎盘部位和胎盘植入不但表达MMP-2,而且多数病例MMP-9（＋）,但阳性强度弱,TIMP-1和TIMP-2（-）;水泡状胎块较强表达MMP-2,伴持续性滋养细胞疾病MMP-9和TIMP-1、2（＋）;侵袭性水泡状胎块和绒毛膜癌MMP-2和MMP-9表达明显增强,TIMP-1和TIMP-2多数（＋）.结论在病理性妊娠中MMP-9活性增强可导致滋养细胞发生过度浸润.MMP-9的过度表达和TIMP-1、2的轻微增加,可能共同增强了肿瘤细胞的侵袭能力.     

组织因子途径抑制物2基因真核表达载体的构建及鉴定

目的:构建人组织因子途径抑制物2(tissuefactorpathwayinhibitor2,TFPI-2)基因的真核表达载体pEGFP-C1-TFPI-2,并对其进行酶切鉴定。方法:实验于2006-09/12在安徽省立医院中心实验室完成。实验方法:①从人胎盘组织中提取总RNA,反转录合成cDNA,以特异性引物扩增TFPI-2基因全长mRNA。②扩增产物回收纯化后用限制性内切酶酶切,与经同样处理的载体pEGFP-C1进行连接反应,连接产物转化感受态大肠杆菌DH5α。③碱变性法提取质粒进行限制性内切酶酶切分析,并进行DNA序列测定。结果:①成功克隆了708bp的TFPI-2基因片段。②构建了人TFPI-2基因的真核表达载体pEGFP-C1-TFPI-2,经限制性内切酶酶切,电泳分析后得到了大小分别为708bp的目的基因片段和4.6kb的载体片段,测序结果与TFPI-2mRNA的cDNA序列吻合。结论:通过基因重组技术,构建了稳定表达TFPI-2的人TFPI-2的真核表达载体pEGFP-C1-TFPI-2。     

组织因子途径抑制物-2对胰腺癌细胞增殖的影响

目的：检测人胰腺癌组织中组织因子途径抑制物-2（TFPI-2）基因的表达,探讨其对胰腺癌细胞增殖的影响.方法：采用免疫组织化学方法检测43例胰腺癌及9例正常胰腺组织中TFPI-2及Ki-67蛋白的表达.结果：胰腺癌中TFPI-2的表达低于正常胰腺组织,其表达水平与胰腺癌临床分期及转移有关, 于Ⅰ、Ⅱ期及无转移的胰腺癌组织中的表达高于Ⅲ、Ⅳ期及有转移的胰腺癌组织（P＜0.05）.其表达水平与胰腺癌细胞增殖活性呈负相关（rs=- 0.339,P＜0.05）.结论：TFPI-2基因在胰腺癌中呈低表达,能抑制肿瘤细胞的增殖,可能参与了胰腺癌细胞周期的调控.     

基质金属蛋白酶/金属蛋白酶组织抑制因子在大鼠创伤性深静脉血栓形成中的表达及作用(英文)

背景:创伤性深静脉血栓形成机制复杂,大量研究主要集中在临床观察和流行病学层面,其分子机制研究一直没有新的突破.目的:应用基因芯片技术研究创伤性深静脉血栓形成过程中基质金属蛋白酶的表达变化规律,探讨其在创伤性深静脉血栓形成中的作用.方法:SPF级8～12周龄SD大鼠150只,体质量250～300 g,随机分为正常对照组10只和模型组140只.模型组140只采用直接钳夹股静脉+双后肢石膏固定方式,建立大鼠创伤性深静脉血栓动物模型.又分为7组亚组,创伤即刻组(0.5 h)、血栓形成初始期组(2.5 h)、高峰期血栓形成组(25 h)、高峰期血栓不形成组(25 h)、血栓消退组(72 h)、血栓不消退组(72 h)和创伤后持续无血栓组(168 h),每组10只.在相应时相点无创切取股静脉血管组织,随后抽取总RNA,采用Genechip Rat Genome 4302.0芯片对股静脉血管组织进行基因表达检测.观察创伤性深静脉血栓形成与不形成和消退与不消退的发生率;运用基因芯片数据分析方法分析基质金属蛋白酶和金属蛋白酶组织抑制因子在各时相点的表达.结果与结论:模型组死亡3只,147只大鼠进入结果分析.造模后25 h血栓形成率约为50.5%,血栓不形成率约为49.5%;168 h,有血栓的大鼠中大概有56.7%发生消退,43.3%的血栓持续存在不消退.基质金属蛋白酶和金属蛋白酶组织抑制因子等均呈不同程度差异表达.血栓不消退状态时,基质金属蛋白酶仍呈高表达,金属蛋白酶组织抑制因子表达在血栓形成过程中处于下调状态,在消退过程呈明显抑制状态.在创伤性深静脉血栓形成与消退演化过程中,创伤后基质金属蛋白酶与创伤性深静脉血栓之间存在密切的关系,基质金属蛋白酶/金属蛋白酶组织抑制因子可能是影响血栓生物学状态的重要因素之一.     

Tissue factor pathway inhibitor and other endothelium-dependent hemostatic factors in elderly individuals with normal or impaired glucose tolerance and type 2 diabetes

OBJECTIVE: Impaired glucose tolerance (IGT) is believed to be a prediabetic phase that precedes the development of type 2 diabetes. In elderly subjects, IGT and diabetes are both independently associated with the occurrence of cardiovascular disease. Endothelial damage precedes atherosclerotic changes of the vascular wall. Therefore, several markers of endothelial dysfunction were examined in elderly subjects with IGT and elderly patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: Von Willebrand factor (vWF), tissue plasminogen activator (t-PA), plasminogen activator inhibitor type-1 (PAI-1), and thrombomodulin were studied as markers of endothelial dysfunction in a population-based study of elderly subjects with normal glucose tolerance (NGT) or IGT and type 2 diabetes. In addition to these endothelium-dependent factors, we also investigated tissue factor pathway inhibitor (TFPI) activity in relation to metabolic parameters and cardiovascular risk factors. RESULTS: All data were adjusted for age. Increased levels of vWF antigen, t-PA antigen, and PAI-1 activity were seen in the IGT and diabetic group compared with the NGT group. TFPI activity and thrombomodulin levels were increased in all elderly subjects, and no differences were seen between the groups. There was a positive association between HbA(1c) and TFPI activity and vWF antigen. Fasting blood glucose levels correlated with vWF antigen, t-PA antigen, and PAI-1 activity, whereas urine albumin excretion correlated with TFPI activity, vWF antigen, and PAI-1 activity. Serum insulin levels correlated strongly not only with vWF antigen and t-PA antigen but also with PAI-1 activity. This correlation did not change after further adjustment for serum glucose and HbA(1c), which may suggest that in the elderly subjects, impaired fibrinolysis is probably associated with insulin resistance. There were no associations between the endothelium-dependent hemostatic factors and lipids, except for a negative correlation between HDL cholesterol and thrombomodulin. CONCLUSIONS: In elderly subjects with IGT, several endothelium-dependent hemostatic factors are already consistently increased, indicating endothelial damage in this stage.     

A novel anticoagulant activity assay of tissue factor pathway inhibitor I (TFPI).

Tissue factor (TF) pathway inhibitor I (TFPI) is the physiological inhibitor of TF-induced blood coagulation. Circulating blood contains full-length TFPI and TFPI truncated at the C-terminal end. Previous studies have shown that full-length TFPI exerts a stronger anticoagulant effect on diluted prothrombin time (DPT) than truncated TFPI, and it has been suggested that full-length TFPI is biologically more important in vivo. The objective of this study was to develop and validate an assay of TFPI anticoagulant activity. TFPI anticoagulant activity was assayed using a modified DPT assay. Plasmas were incubated in the absence and the presence of TFPI-blocking antibodies. Results were expressed as a ratio with the clotting time in the presence of anti-TFPI as the denominator. The ratio was normalized against a ratio obtained with a reference plasma. The assay was compared with assays of TFPI free antigen, total antigen, and bound TFPI, and TFPI chromogenic substrate activity. We performed all tests in 436 healthy individuals. The normalized TFPI anticoagulant ratio was strongly associated with TFPI free antigen (r = 0.73) but was weakly associated with TFPI chromogenic substrate activity (r = 0.46), TFPI total antigen (r = 0.48), and bound TFPI (r = 0.30). TFPI chromogenic substrate activity was strongly associated with TFPI total antigen (r = 0.73). We have developed a novel assay of TFPI anticoagulant activity in plasma, which may be considered a functional assay of full-length TFPI. Further studies are needed to establish the role of TFPI anticoagulant activity for thrombotic disorders.     

组织因子途径抑制物-1对无复流作用的实验研究

目的 探讨不同剂量外源性重组人组织因子途径抑制物-1 (TFPI-1)防治实验性无复流(NR)的作用.方法 北京安贞医院实验室,新西兰大白兔52只,结扎回旋支中段120 min,再灌注60 min.在再灌注即刻随机(随机数字法)分为对照组及大、中、小剂量TFPI-1组[分别为1000 ng/kg、100 ng/kg及10 ng/kg静脉注射,随后10 ng/( kg·min)、l ng/( kg·min)及0.1nig/( kg·min)静脉滴注,n=13只/组].活体硫磺素S及Evan’s蓝心肌着色测定解剖无复流面积(NA)和缺血面积(IA).NR严重程度用NA/IA表示.比较不同组别NR严重程度,并观察血栓形成及心肌损伤情况.各组间基本情况、心肌缺血及NR严重程度比较用完全随机设计单因素方差分析,均数两两比较采用LSD检验.结果 各组体质量、缺血面积比较差异无统计学意义(P＞0.05).大、中、小剂量TFPI-1组和对照组NR严重程度分别为(0.210±0.061)、 (0.389±0.1100、(0.478±0.077)和(0.536±0.061).大剂量TFPI-1组NR严重程度较其他三组明显减轻(P＜0.0l);中剂量TFPI-1组NR严重程度明显低于对照组(P＜0.0l)和小剂量TFPI-1组(P＜0.05);小剂量TFPI-1组和对照组NR严重程度差异无统计学意义(P＞0.05).大剂量TFPI-1组血栓形成减少,无复流区心肌组织损伤减轻.结论 外源性TFPI-1可显著减轻兔NR严重程度,且随剂量增大作用增强,再灌注时静脉应用TFPI-1可防治NR现象.