Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.21.7 (plasmin)
9,023 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fluid cadaveric blood is generally known as a characteristic of sudden death. However, it has been reported that soft blood clots have been observed in a number of cases of sudden death after alcohol drinking. Such a tendency was also recognized on autopsy cases in our laboratory. This study was carried out to reveal the effects on clotting and fibrinolytic system in golden hamsters under acute alcohol intoxication. Furthermore, the influences of ether anaesthesia were also observed. Activities of clotting and fibrinolytic factors were measured with fluorogenic peptide substrate. Prothrombin and factor X activities began to decrease 1 hr after administration of alcohol. But thrombin-like and factor Xa-like activities significantly increased after 1 hr and then returned to the initial value 4 hr after administration. Plasminogen activity began to decrease 1 hr after administration, whereas plasmin-like and t-PA-like activities increased after 1 hr and returned to the initial values or decreased after 4 hr. These results show that under acute alcohol intoxication clotting and fibrinolytic factors (prothrombin, factor X and plasminogen) in golden hamsters were converted temporarily to their active forms (thrombin, factor Xa and plasmin). No influence of only ether anaesthesia on clotting and fibrinolytic activities was observed. At 1 hr after administration of alcohol some effects of ether anaesthesia on prothrombin, prekallikrein and kallikrein were observed and then were not observed after 4 hr. But it seems that the influence of ether anaesthesia on clotting and fibrinolytic activities was negligible in the process after alcohol consumption.
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PMID:[Clotting and fibrinolytic activities in acute alcoholic golden hamsters with or without ether anaesthesia]. 192 Sep 21

Slow and fast contracting muscles differ in their innervation and electrophysiological properties as well as in their regenerating potentialities. The purpose of the present work was to investigate the expression of plasminogen activators and its possible relation to each type of muscle. Slow (Soleus) and fast (Extensor Digitorum Longus) muscles were obtained from white Wistar rats. Before sectioning the muscles, the euthanized rats were perfused with cold phosphate buffer saline to avoid interference by circulating proteases and inhibitors. Muscle extracts were pounded in an ice-cold Potter tube. Plasminogen activators (PAs) were assayed by fibrin zymography and by both liquid and solid-phase fibrin spectrophotometric assays for the detection of PAs activity. Both urokinase (uPA) and tissue-type plasminogen activator (tPA) activities corresponding to proteins of 38 kDa and 65 kDa molecular masses, were detected in the extracts. Slow muscles contained higher amounts of both activators than fast muscles, but the relative amount of uPA was higher in both types of muscles. In addition, the characteristics of each type of extracts differed somewhat: the fast muscle activity curve was typical of an accelerating process, while the slow muscle curve showed an activity probably related to already formed plasmin or to some other trypsin-like enzyme. These results suggest that the amount of plasminogen activators could be a new criterion of discrimination between slow and fast skeletal muscles.
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PMID:Slow and fast rat skeletal muscles differ in their plasminogen activator activities. 211 33

The ability of tissue plasminogen activator (tPA) to induce human umbilical vein endothelial (HUVE) cell migration was studied using an in vitro, serum-free wound assay system. At pharmacological doses, tPA stimulated HUVE cell migration dose-dependently. Treatment of cells with epsilon amino caproic acid (EACA) to detach cell-surface and extracellular matrix bound plasminogen, which could lead to plasmin generation, resulted in increased HUVEcell migration on stimulation with tPA.Plasminogen activator inhibitor-1 (PAI-1), a natural plasminogen activator inhibitor, abolished tPA-induced HUVEcell migration. These results demonstrate for the first time that tPA is capable of stimulating endothelial cell migration in wound assays and this effect is susceptible to PAI-1 inhibition.
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PMID:Tissue-plasminogen activator stimulates endothelial cell migration in wound assays. 212 Nov 40

Plasminogen activator (PA), which catalyzes the conversion of plasminogen to the proteinase plasmin, has been implicated in a variety of cutaneous disorders. Lesional epidermis from patients with psoriasis, pemphigus, bullous pemphigoid, and Hailey-Hailey disease contains elevated levels of tissue-type PA (tPA) activity compared to non-lesional epidermis or to epidermis from normal individuals. In the present study, we have used Northern blot analysis to demonstrate that mRNA for tPA is detectable in lesions from patients with psoriasis, pemphigus, and bullous pemphigoid, but is not detectable in normal epidermis. These data strongly suggest that the tPA enzymatic activity present in lesional epidermis results from enhanced synthesis of the enzyme in situ, secondary to elevated steady-state levels of tPA mRNA. Cultured keratinocytes likewise are shown to contain tPA mRNA. Previous investigators have suggested that the phenotypes of keratinocytes in culture, psoriatic epidermis, and epidermis in the process of wound reepithelialization are comparable. Our findings, combined with those of other investigators, suggest that elevated tPA expression may be another common feature of epidermis under these circumstances.
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PMID:mRNA for tissue-type plasminogen activator is present in lesional epidermis from patients with psoriasis, pemphigus, or bullous pemphigoid, but is not detected in normal epidermis. 212 33

Plasminogen activator (PA) is a specific serine protease which catalyses conversion of the inactive plasminogen into the broad-spectrum protease, plasmin. PA exists in two structurally related forms known as tissue-type PA (tPA) and urokinase-type PA (uPA). Conversion of normal cells into a malignant state frequently leads to increased production of uPA. There is increasing evidence that uPA is directly involved in the process of metastasis. High levels of uPA in human breast cancers is a marker for poor prognosis. Finally, uPA may be a target for anti-metastatic agents, either by inhibition of its synthesis, inhibition of its activity or its binding to receptor.
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PMID:Plasminogen activators and cancer. 213 47

Plasminogen, plasmin, and plasminogen activator (PA) activities and PA and PA inhibitor (PAI) contents were measured in granulosa (GC) and theca interna cell extracts and follicular fluid (FF) obtained from preovulatory follicles of prepubertal gilts treated with eCG and hCG to induce follicular growth and ovulation. Plasmin activity in FF increased just before the time of expected ovulation. This increase was not attributable to changes in plasminogen levels, which remained relatively constant during preovulatory follicular development. The increase in follicular plasmin levels was associated with significant (p less than 0.01) increases in PA activity and content and decreases in PAI content in GC and FF. Western blot analysis suggested that follicular PA activity was represented principally by two forms of tissue type PA (t-PA) each with a pI of 7.8 and with molecular masses of 72,000 and 78,000 daltons, respectively. Two PA-PAI complexes of 126,000 and 130,000 daltons were observed. These complexes were partially dissociated with nucleophilic agents into two t-PA-like forms and a 52,000-dalton PAI protein with a pI of 4.8. Biochemical characteristics of the PAI protein suggest that it belongs to the same class of inhibitors as bovine and human PAI-1. These data indicate that rupture of the porcine ovarian follicle is temporally associated with a net increase in PA activity and an increase in plasmin activity. The increase in PA activity appears to be regulated by changes in PA and PAI content.
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PMID:Changes in and partial identification of the plasminogen activator and plasminogen activator inhibitor systems during ovarian follicular maturation in the pig. 214 59

The low density lipoprotein (LDL) variant, lipoprotein(a) (Lp(a)) is a risk factor for coronary heart disease, and in this study we have examined its interaction with the arterial wall. Samples of normal intima and atherosclerotic lesions were extracted with buffer containing EDTA and protease inhibitors and assayed for LDL and Lp(a) by radial immunodiffusion. The extract tissues were washed, then incubated with plasmin and the amounts of LDL and Lp(a) released into the digest were measured. Intimal Lp(a) concentrations were compared to Lp(a) in the patients' blood. Levels of both soluble and plasmin-releasable Lp(a) were related to type of intimal sample and blood Lp(a) level. In early proliferative lesions there was a significant correlation between plasmin-releasable Lp(a) and blood Lp(a) (r = 0.631, P less than 0.002). Highest levels of plasmin-releasable Lp(a) were found in more advanced lesions that had accumulated some lipid. In extracts the amounts of LDL were 5-20 fold greater than Lp(a) but in the plasmin digests Lp(a) could account for most of the apoB detected, suggesting that Lp(a) may bind to fibrin in the lesion through its plasminogen-like structures and thus contribute to lipid accumulation in fibrous plaques. Plasminogen cannot be detected by rocket immunoelectrophoresis in samples from about two-thirds of aortas, and it seemed possible that the large plasminogen-like apo(a) component of Lp(a) was interfering with intimal uptake or retention of plasminogen, or its immunoassay. However, in 28 samples of intima or thrombi from 16 patients there was no relation between amounts of Lp(a) and plasminogen.
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PMID:The inter-relation of fibrin, lipoprotein(a) and plasminogen in human atherosclerotic lesions. 215 35

A fibrin glue preparation has been obtained from pooled human plasma using a procedure which includes a solvent-detergent (SD) treatment to inactivate lipid-enveloped viruses. The SD treatment inactivated greater than or equal to 5.5 log10 of HIV in less than 45 min, and greater than or equal to 5 log10 and greater than or equal to 6.5 log10 of VSV and Sindbis virus, respectively, in less than 2 h. The product was found to contain high quantities of fibrinogen (116 +/- 2.49 g/l; n = 12), factor XIII (35 +/- 2.88 U/ml) and von Willebrand factor (23 +/- 1.9 U/ml ristocetin cofactor activity), and relatively low levels of fibronectin (5.9 +/- 0.51 g/l). Plasminogen, the precursor of plasmin, which may play a negative role by decreasing the resistance of the fibrin clot, was at only 0.03 g/l. Cellulose acetate electrophoresis showed 95% gamma-proteins and 5% alpha-2-beta proteins. Sodium dodecyl sulfate polyacrylamide gel electrophoresis under reducing conditions detected three main protein bands with apparent molecular weights of 65, 56 and 47 kilodaltons, probably corresponding to the alpha, beta, and gamma fibrinogen subunits. Other characteristics of the product included (1) high clottability of fibrinogen (over 85%); (2) absence of low molecular weight fibrin degradation products; (3) rapid solubilization at room temperature (less than 10 min); (4) high tensile strength (202 +/- 27 g/cm2 after 2 h of application), and (5) high elasticity of the fibrin clot. In addition, scanning electron microscopy revealed a highly organized structure showing tridimensional arrangement of the fibrin fibers. SD treated fibrin glue should efficiently replace autologous fibrinogen or cryoprecipitate preparations for surgical application.
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PMID:Biochemical and physical properties of a solvent-detergent-treated fibrin glue. 216 Jan 46

The capacity of human monocytoid cell lines and peripheral blood monocytes to modulate their expression of plasminogen receptors has been assessed. After PMA stimulation, THP-1 or U937 monocytoid cells were separated into adherent and nonadherent populations. Plasminogen bound to adherent cells with similar capacity and affinity as to nonstimulated cells. In contrast, the nonadherent cells bound plasminogen with 5-17-fold higher capacity (without a change in affinity). This increase was selective as urokinase bound with similar affinity and capacity to the adherent and nonadherent populations. Upregulation of plasminogen receptors on the nonadherent monocytoid cells was rapid, detectable within 30 min, and reversible, adhesion of the nonadherent cells resulted in a sixfold decrease in plasminogen binding within 90 min. The increase in plasminogen binding to the nonadherent cells was associated with a marked increase in their capacity to generate plasmin activity from cell-bound plasminogen. PMA stimulation of human peripheral blood monocytes increased their expression of plasminogen receptors by two- to fourfold. This increase was observed in both adherent and nonadherent monocytes. Freshly isolated monocytes maximally bound 5.0 x 10(5) plasminogen molecules per cell, whereas monocytes cultured for 18 h or more maximally bound 1.7 x 10(7) molecules per cell, a 30-fold difference in receptor number. These results indicate that both monocytes and monocytoid cell lines can rapidly and markedly regulate their expression of plasminogen binding sites. As enhanced plasminogen binding is correlated with an increased capacity to generate plasmin, an enzyme with broad substrate recognition, modulation of plasminogen receptors may have profound functional consequences.
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PMID:Regulation of plasminogen receptor expression on human monocytes and monocytoid cell lines. 217 Apr 26

Plasminogen activators (PAs) are specific proteolytic enzymes which convert the inactive proenzyme plasminogen to plasmin. The plasmin formed is a potent and nonspecific protease which cleaves blood fibrin clots and several other extracellular proteins. In addition to their primary role in the initiation of fibrinolysis, PAs are implicated in a variety of basic biological processes, such as, degradation of the extracellular matrix, tumor invasiveness, tissue remodelling, and cellular differentiation. This review describes recent observations on the biochemical and biophysical characteristics of the different components of the plasminogen activation system. This complex system includes: the proenzymes of tissue type PA (tPA) and urokinase type PA (uPA); the active enzymes tPA, uPA and plasmin; the substrate plasminogen; several natural inhibitors of PA and plasmin activity; and the cellular receptors that bind the proenzymes, enzymes, and inhibitor-enzyme complexes. Through the coordinated interactions of these components, the location, timing, and extent of potent proteolytic activity is controlled. Recent findings on the structure, properties, biological functions, and regulation of the different components of the plasminogen activation cascade are reviewed. Current methods for assay of the amount and activity of the enzymes, inhibitors, and receptors are described. Observations implying specific functions of the system in health and disease, and its potential utilization for diagnosis are examined. Specifically, the potential application of PAs as laboratory markers of neoplasia, as diagnostic tools in diseases of the blood clotting system, their use for monitoring of thrombolytic therapy, and their possible relevance in certain disease states are described.
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PMID:Biochemical and biological aspects of the plasminogen activation system. 219 30


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