纤溶药物出血机制的进展及分析

传统的溶栓药多为纤溶酶原激活剂类药物,严重依赖于患者本身的纤溶酶原水平,溶栓效果受到限制。与之不同的是,纤溶药物具有直接纤维蛋白水解活性,能够直接溶解血栓,是一种新型的具有“直接疗效”的溶栓药物,具有更高的溶栓效率和安全性,是目前的研究热点之一。虽然能作为纤溶药物的纤溶物质不断被发现研究,但真正开发成新药、成功运用于临床的却很少,主要是其出血风险限制了发展。本文综合国内外有关纤溶药物的最新研究进展,就其出血机制及应对策略进行系统综述,总结了纤溶药物的5类出血机制,提出了3类应对策略,为研发更安全、高效的纤溶药物提供理论依据。     

蚓激酶及其在心血管疾病中的研究进展

蚓激酶是近年发现的一种新型溶栓物质,具有纤溶活性和溶栓活性,在心血管疾病中受到了极大关注,获得广泛应用。本文综述了蚯蚓纤溶酶结构特点、作用机制及心血管临床应用等的研究成果。     

溶栓胶囊治疗血栓性疾病的临床评价

溶栓胶囊是是山西中远威药业有限公司研制的新型抗血栓药。它是从传统中药特种地龙(双胸蚯蚓)中分离提取出的含纤溶酶、纤溶酶原激活物和胶原酶。因而具有抗凝、溶纤和溶栓作用。经过全国数十家医院的临床观察和验证,其主要适应症及功效如下:     

浅谈溶栓药的特点及应用

在1959年已经用链激酶(SK)治疗心肌梗死,在80年代前可供使用的溶栓药除SK外还有尿激酶(UK),80年代以来,先后有基因重组组织型纤溶酶原激活剂(rt-PA)及其突变体、TNKt-PA前尿激酶(Pro-UK)和葡激酶(SAK)。至今所有溶栓药的基本药理都是将纤溶酶原转变成纤溶酶,纤溶酶可裂解纤维蛋白原,纤维蛋白(血栓的重要成分),凝血因     

施爱克

[通用名称]recombinant staphylokinase for injection（r-Sak）,注射用重组葡激酶 　　[性状]为白色疏松体,溶解后为澄明液体. 　　[药理作用]本品具有溶栓作用.其溶栓机制为：与血浆中纤溶酶原形成复合物,激活纤溶系统,促使纤溶酶原转化为纤溶酶,特异性地降解纤维蛋白,使血栓溶解.     

蛇毒纤溶酶溶栓作用的研究进展

蛇毒纤维蛋白(原)溶解酶(简称纤溶酶)主要通过降解纤维蛋白(原)而起到抑制血栓形成的作用,是一种潜在的强力溶栓剂.本文主要对近年来蛇毒纤溶酶的性质和溶栓机制的研究及其应用做一综述.     

浅谈溶栓药的特点及应用

在1959年已经用链激酶(SK)治疗心肌梗死，在80年代前可供使用的溶栓药除SK外还有尿激酶(UK)，80年代以来，先后有基因重组组织型纤溶酶原激活剂(rt-PA)及其突变体、TNKt-PA前尿激酶(Pro-UK)和葡激酶(SAK)。至今所有溶栓药的基本药理都是将纤溶酶原转变纤溶酶，纤溶酶可裂解纤维蛋白原，纤维蛋白(血栓的重要成分)，凝血因子     

尖吻蝮蛇毒无出血活性纤溶酶对动物血栓的溶栓作用

目的　研究尖吻蝮蛇毒 (Agkistrodonacutus)无出血活性的纤溶酶对动物血栓形成的溶栓作用。方法　采用家兔动物血栓和大白鼠静脉血栓模型 ,静脉注射尖吻蝮蛇无出血活性纤溶酶 ,分 3个剂量组 (n =6) ,其剂量分别为 0 1 4、0 7、1 4mg·kg- 1 ,用生理盐水作阴性对照。测定尖吻蝮蛇毒无出血活性的纤溶酶对动脉血栓、静脉血栓的溶栓作用。结果　给药后 ,尖吻蝮蛇毒无出血活性的纤溶酶对动脉血栓、静脉血栓湿重均有减轻作用 ,与生理盐水对照组相比 ,差异均有显著性 (P <0 0 5或P <0 0 1 )。结论　尖吻蝮蛇无出血活性纤溶酶对动物血栓有明显的溶栓作用 ,具有潜在的临床应用价值     

海洋假单胞菌纤溶酶的体外溶栓实验研究

目的确证血纤维蛋白溶酶的体外溶栓作用。方法用血纤维蛋白平板法、体外血块溶解实验研究该酶的纤溶特点及对血块的溶解作用。结果可直接水解血纤维蛋白 ,溶栓活性同蝮蛇抗栓酶类似 ,但对红细胞形态没有影响。结论血纤维蛋白溶酶是一种直接纤溶酶 ,有较强的纤溶活性     

CK纤溶酶的分离纯化及其体外溶栓研究

目的:探索CK纤溶酶的分离纯化方法及观察其体外溶栓作用.方法:先用硫酸铵沉淀,然后通过羧甲基琼脂糖快速胶柱层析后进行分离纯化,并用SDS-PAGE测定纯度、相对分子质量,及其对人血凝块的水解活性.结果:得到了电泳纯的酶,其分子质量为27 000,且具有显著的体外溶栓作用.结论:CK纤溶酶有望开发成为一种新型口服溶栓药物.     

Design,preparation and activity evaluation of novel recombinant thrombolytic proteins

Recombinant tissue plasminogen activator (rPA) has been used as a thrombolytic agent. However, considerable improvements have been done to prolong its plasma half-life (t_1/2) and reduce its side effects, such as intracranial hemorrhage. Based on these improvements, a mutant of rPA, mrPA, was designed by mutating its PAI-1 binding site to extend its t_1/2. Furthermore, a fusion protein conjugating mrPA with NR3 was designed, which was a rAcAp5 mutant with a platelet GPIIb/IIIa-binding RGD motif, to enhance the ability of targeted-thrombus and thrombolysis. The synthesized DNA sequences coding the two proteins were amplified by PCR, cloned into pET30a to construct recombinant plasmids pET30a-mrPA and pET30a-mrPA-NR3, and transformed into E. coli BL21 (DE3). The two proteins were expressed in inclusion bodies induced by isopropyl β-D-1-thiogalactopyranoside. After purified to qualified purity using one-step Ni affinity chromatography, the denatured proteins were refolded by dialysis. Their thrombolytic effects in vitro and in vivo were evaluated. In vitro 3.5 and 7 μmol/L of mrPA significantly reduced thrombus weight; 1.75, 3.5 and 7 μmol/L of mrPA-NR3 also significantly reduced the thrombus weight, and mrPA-NR3 displayed stronger thrombolytic effects than mrPA at 7 μmol/L. In vivo both mrPA and mrPA-NR3 showed significantly thrombolytic effect at 60−240 μmol/kg in thrombolytic model of inferior vena cava. Importantly, mrPA-NR3 exhibited more potent thrombolytic effect than both mrPA and rhM-tPA (positive control) at 240 μmol/kg. In addition, these two novel proteins did not increase bleeding time while they exerted thrombolytic effect. In conclusion, we engineered two novel proteins and proved that fusion protein had better thrombolytic effect than non-fusion protein, and the results suggest that dual thrombolytic mechanism or thrombus-target potentiated the thrombolytic effect of rPA and alleviated hemorrhage side reaction. This study may shed light on the development of novel thrombolytic agents with targeted thrombolysis and reduced side effects.     

溶栓剂的研究进展

本文介绍了血栓形成原因与溶栓机制，阐述了溶栓剂的发展过程和开发前景，为研究安全、高效、低廉的溶栓药物指明了方向。     

溶血栓药物研究进展

血栓性疾病如心肌梗死、动脉血栓和脑梗死等严重危害人类的身体健康,溶栓被认为是治疗血栓性疾病的重要方法之一。近年来溶栓药物的研发主要集中在两方面,一方面为通过基因工程和单克隆抗体技术改造的新型纤溶酶原激活剂药物,另一方面为新来源的溶栓药。本文将先概述溶栓机理,并对近年来溶栓药物的研究进展及发展方向进行综述。     

扎冲十三味丸的溶栓作用机制及对凝血系统的影响

目的:探讨扎冲十三味丸的溶栓作用及其初步机制,同时评价其对凝血系统的影响及急性毒理试验。方法:采用体内和体外溶栓的方法评价扎冲十三味丸对电刺激大鼠颈动脉血栓的溶栓作用;应用ELISA方法测定扎冲十三味丸对家兔血浆组织型纤溶酶原激活物(tPA)和纤溶酶原激活物抑制物(PAI-1)活性的影响;同时评价扎冲十三味丸凝血酶原时间(PT)、活化部分凝血活酶时间(APTT)、凝血酶时间(TT)、纤维蛋白原(Fib)含量和血液流变学的影响。扎冲十三味丸对实验小鼠的急性毒理试验。结果:0.432 g· kg^-1(中)和0.864 g· kg^-1(高)扎冲十三味丸组于末次给药后2~6 h均明显抑制血浆PAI-1活性, 显著提高血浆tPA活性。0.864,1.728 g·kg^-1组和复方丹参滴丸0.12 g·kg^-1组明显降低Fib水平,明显延长TT,3种剂量的扎冲十三味丸对APTT和PT无明显影响,对红细胞电泳、高切、中切和低切均无明显影响;全部小鼠健存,无中毒反应。结论:扎冲十三味丸抑制PAI-1活性,同时提高tPA的活性可能是其具有较好溶栓作用的分子机制。扎冲十三味丸可影响内凝和外凝系统,减少血管壁纤维蛋白的沉积,也提示在临床用药过程中,有可能发生出血倾向,需密切监测患者的凝血系统;无明显急性毒理反应。     

重组人组织型纤溶酶原激活剂及其突变体的溶血栓研究

目的 比较重组人组织型纤溶酶原激活剂(rht-PA)及其突变体FsGGI和FrGGI的溶血栓作用,验证突变体的构建思想。方法 采用兔颈静脉溶栓模型和体外溶栓试验对纯化的rht-PA及其突变体FsGGI和FrGGI进行家兔体内外溶栓研究。结果 rht-PA、FsGGI及FrGGI三者均有体内外溶栓作用,体外溶栓能力基本相似;体内溶栓活力突变体FsGGI与FrGGI类似,均显著高于rht-PA,溶栓度分别为20.1％、49.1％和46.6％。在体内溶栓作用的同时均未引起血浆纤维蛋白原滴度下降。结论 溶栓作用是血栓特异性的,两种突变体是优于野生型t-PA的溶栓剂,上游的构建思想是正确的。     

尿激酶溶栓治疗急性心肌梗死疗效观察

目的观察尿激酶静脉溶栓治疗急性ST段抬高型心肌梗死的疗效。方法选择该院收治急性ST段抬高型心肌梗死患者132例,按是否符合溶栓条件分两组,溶栓组50例,对照组82例,对照组采用常规治疗,溶栓组在对照组基础上实施尿激酶静脉溶栓治疗。结果溶栓组在冠状动脉再通率、心力衰竭、梗死后心绞痛、病死率分别与对照组相比,差异有统计学意义（P〈0.05）,溶栓组胸痛缓解迅速、明显,但出血并发症高于对照组。结论急性心肌梗死尿激酶溶栓疗效确切、安全,溶栓治疗效果与溶栓开始时间密切相关。     

单环刺螠抗血栓组分的分离纯化和药效学研究

目的从单环刺螠中分离纯化单环刺螠抗血栓组分(ATCUU),并进行有关药效学研究。方法新鲜单环刺螠经过抽提,离心并超滤得到粗提物,并通过DEAE离子交换和凝胶色谱进行分离纯化,得到具有抗血栓作用的组分。并采用动物模型,进行了该组分的抗血栓作用的药效学研究。结果经分离纯化得到的ATCUU,经口给药后能明显减少动脉血栓的湿重和干重,显著延长大鼠的凝血时间,凝血酶原时间和血浆凝血酶时间,且显示一定的量效关系。结论ATCUU具有较好的溶栓效果,有望开发成为新的溶栓药物。     

Role of endogenous tPA in stroke]

The role of endogenous tissue-type plasminogen activator (tPA) on focal cerebral ischemic injury (FII) after middle cerebral artery (MCA) occlusion was studied by using tPA gene deficient (KO) mice and wild type (WT) mice. MCA was occluded by thrombosis induced by 3 different intensities of photochemical damage of MCA. FII size in KO mice was smaller than in WT mice in mild damage whereas it was larger in severe damage. These results suggested that endogenous tPA protected FII through its thrombolytic action on transient occlusion with mild damage, but deteriorated on persistent occlusion with severe damage. Cerebral hemorrhage associated with antithrombotic and thrombolytic therapy in acute stroke is a major clinical problem. We investigated the roles of endogenous tPA and MMPs in hemorrhagic cerebral infarction associated with heparin. We demonstrated that heparin administration caused cerebral hemorrhage in WT but not in KO. Heparin administration increased tPA activity and its mRNA expression in WT. We also observed an induction of MMP9 and its mRNA expression by heparin administration in WT but not in KO. Our findings suggest that endogenous tPA plays an important role in heparin-produced cerebral hemorrhage via MMP9 induction and activation.     

A targeted ferritin-microplasmin based thrombolytic nanocage selectively dissolves blood clots

The use of thrombolytic therapies is limited by an increased risk of systemic hemorrhage due to lysis of hemostatic clots. We sought to develop a plasmin-based thrombolytic nanocage that efficiently dissolves the clot without causing systemic fibrinolysis or disrupting hemostatic clots. Here, we generated a double chambered short-length ferritin (sFt) construct that has an N-terminal region fused to multivalent clot targeting peptides (CLT: CNAGESSKNC) and a C-terminal end fused to a microplasmin (μPn); CLT recognizes fibrin–fibronectin complexes in clots, μPn efficiently dissolves clots, and the assembly of double chambered sFt (CLT-sFt-μPn) into nanocage structure protects the activated-μPn from its circulating inhibitors. Importantly, activated CLT-sFt-μPn thrombolytic nanocage showed a prolonged circulatory life over activated-μPn and efficiently lysed the preexisting clots in both arterial and venous thromboses models. Thus, CLT-sFt-μPn thrombolytic nanocage platform represents the prototype of a targeted clot-busting agent with high efficacy and safety over existing thrombolytic therapies.