Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.68 (tissue plasminogen activator)
 11,311 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Changes in the plasma levels of components of the fibrinolytic system have been investigated in 80 patients suffering from gastrointestinal carcinomas. Urokinase antigen (RIA), tissue-type plasminogen activator antigen (ELISA) and plasminogen activator inhibitor (functional assay) were determined. Patients with pancreatic and colorectal carcinoma and metastases as well as those without metastases revealed significantly increased plasma urokinase levels. Those with gall bladder or gastric carcinoma did not show significantly elevated urokinase antigen levels compared to age-matched controls. Determination of tissue-type plasminogen activator antigen in all four carcinoma groups did not reveal significant differences when compared to an age-matched healthy control group. The concentrations of plasminogen activator inhibitor were significantly increased in all carcinoma groups; there being no differences between the patient groups with or without metastases. No correlations between the different parameters of the fibrinolytic system could be obtained.
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PMID:Pattern of fibrinolytic parameters in patients with gastrointestinal carcinomas. 310 63

Two types of plasminogen activator (tissue-type, tPA; urokinase-type, uPA) have been demonstrated in ovarian granulosa cells, but only tPA activity was found in denuded oocytes. Immature rats were treated subcutaneously with 20 IU pregnant mare's serum gonadotropin (PMSG) to stimulate follicle maturation, followed 2 days later by an injection of 10 IU human chorionic gonadotropin (hCG) to induce ovulation. Cellular plasminogen activator activities were determined by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis followed by a fibrin-overlay technique. Cumulus-oocyte complexes from rats before and after PMSG treatment contained low amounts of tPA, but not uPA, activity. After hCG treatment, tPA activity showed a time-dependent increase, reaching a maximum at 24 h after injection. At 12 and 24 h after hCG treatment, uPA activity was also detected. The appearance of high molecular weight lysis zones further suggested the formation of plasminogen activator-inhibitor complexes. Morphological analysis indicated that the increases in oocyte tPA activity were correlated with the extent of cumulus cell expansion and dispersion. In denuded oocytes, tPA activity also progressively increased during the periovulatory period to a maximum at 24 h after hCG treatment. In contrast, neither uPA activity nor activator-inhibitor complex was detected. Secretion of the proteases was measured in the conditioned media of cumulus-oocyte complexes cultured for 24 h in vitro. Substantial increases in tPA release were found in complexes obtained at 8 and 12 h after hCG injection, with lower secretion from complexes obtained at 24 h after hCG treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Plasminogen activator activity in cumulus-oocyte complexes of gonadotropin-treated rats during the periovulatory period. 310 10

The biofunctional activity of the plasminogen activators urokinase and tissue plasminogen activator has been measured in extracts from 50 colorectal carcinomas and 21 adenomas using a bioimmunoassay. Compared with control mucosa urokinase activity was significantly elevated in adenomas (P less than 0.001) and carcinomas, levels being significantly higher in carcinomas (P less than 0.05). In contrast tissue plasminogen activator activity was reduced in adenomas (P less than 0.01) and carcinomas, levels being significantly lower in carcinomas (P less than 0.01). Although enzyme activity did not relate to Dukes' stage or histological grade urokinase activity was higher in carcinomas with venous invasion (n = 17, P less than 0.05), in those with moderate or extensive local spread (n = 27, P less than 0.05) and in cases where a palliative resection only was feasible because of advanced disease (n = 8, P less than 0.05). Urokinase has been implicated in tissue degradation as well as fibrinolysis and may play a role in tumour invasion and metastasis in human colorectal neoplasia.
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PMID:Role of urokinase in colorectal neoplasia. 311 78

We have studied the mechanism of a transforming growth factor-beta (TGF-beta)-stimulated production of type-1 plasminogen activator inhibitor (PAI-1) in WI-38 human lung fibroblasts. TGF-beta causes an early increase in the PAI-1 mRNA level which reaches a maximal 50-fold enhancement after 8 h. Blocking of protein synthesis with cycloheximide causes an equally strong increase in the level of PAI-1 mRNA. Quantitative studies of the effect of TGF-beta on PAI-1 protein levels in cell extracts and culture media by using monoclonal antibodies are consistent with the effect on PAI-1 mRNA. The results suggest a primary effect of TGF-beta on PAI-1 gene transcription, and also suggest the possibility that the transcription of this gene in non-induced cells may be suppressed by a short-lived negatively regulating protein. Urokinase-type (u-PA) and tissue-type (t-PA) plasminogen activators are decreased in the culture media of TGF-beta-treated cells concomitantly with the increase in PAI-1 accumulation. These findings show that a primary and important biological effect of TGF-beta may be an overall decreased extracellular proteolytic activity, and give an insight into the molecular mechanisms underlying TGF-beta action at the genetic level.
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PMID:Transforming growth factor-beta is a strong and fast acting positive regulator of the level of type-1 plasminogen activator inhibitor mRNA in WI-38 human lung fibroblasts. 311 44

Plasminogen Activator Inhibitors (PA Inhibitor) have recently been identified in plasma. They are directed against t-PA and Urokinase. Two PA Inhibitors have been described: PA Inhibitor 1 from endothelial cells, hepatocytes and platelets and PA Inhibitor 2 from placenta. Enzymatic assays have been developed. They show that plasma levels of PA Inhibitor are very low under normal conditions, but a considerable increase (X10 or 20) is found in several pathological conditions (thrombo embolic disease, atherosclerosis, thrombotic risk factors (obesity, hypertriglyceridemia, diabetes) inflammatory syndrome, post operative period for PA Inhibitor 1, and in some physiological conditions (pregnancy for PA Inhibitor 2). These results plead for a pathogenic role of PA Inhibitor 1 in the development of thrombosis. Pharmacological products able to decrease the plasma level of PA Inhibitor are as yet scarce. Stanozolol, an anabolic steroid, some biguanides such as Metformin possess this property.
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PMID:[Anti-activator inhibitors of plasminogen]. 311 99

Human purified urokinase-type plasminogen activator (u-PA) stimulates chemoattractant activity for human neutrophils using modified Boyden chambers. Checkerboard analysis performed by adding different concentrations of u-PA above and below the polycarbonate filters revealed maximum migration required a positive concentration gradient. These results suggest that uPA was in fact stimulating neutrophil chemotaxis. Incubation of u-PA with an anti-u-PA goat antibody completely abolished the chemotactic activity of u-PA while incubation with the serine protease inhibitor, diisopropyl fluorophosphate, did not reduce chemotactic activity. Purified human tissue-type plasminogen activator demonstrated no chemotactic activity for human neutrophils when tested at concentrations similar to u-PA. These results suggests that the expression of chemotactic activity of u-PA may serve to recruit circulating leukocytes to the inflammatory site.
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PMID:Human urokinase-type plasminogen activator stimulates chemotaxis of human neutrophils. 311 59

To determine if pulmonary perfusion was improved in acute pulmonary embolism after therapy with recombinant human tissue-type plasminogen activator (rt-PA), lung scans were obtained before and a mean of 22 hours after therapy in 19 patients. The posttherapy lung scans were compared with baseline, pretherapy scans with use of two semiquantitative methods--an anteroposterior view method, similar to that used in the Urokinase Pulmonary Embolism Trial, and a segmental method that emphasized pulmonary anatomy. There was an improvement in the defect score from 0.35 to 0.14 (P less than .01) when the anteroposterior view method was used and from 0.37 to 0.16 (P less than .01) when the segmental method was used. These encouraging results in the early posttherapy period suggest that rt-PA is especially effective in improving regional perfusion after pulmonary embolism and that a larger controlled trial of therapy with rt-PA for acute pulmonary embolism should be performed. Scoring lung scans with a segmental method is feasible and appropriate for present-day lung scan technique and should be considered in future studies.
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PMID:Pulmonary perfusion after rt-PA therapy for acute embolism: early improvement assessed with segmental perfusion scanning. 312 66

Two molecular variants of plasminogen activator (PA): urokinase (uPA) and tissue-type plasminogen activator (tPA), have been reported to be synthesized in the rat testis. Data obtained in this study using monospecific antibodies raised against uPA and tPA in immunoblotting and bioimmunoassay protocols consistently demonstrate that only tPA (and not uPA) is synthesized by bovine Sertoli cell-enriched cultures, and is induced by bovine FSH. Zymographic analysis of conditioned medium on gels containing plasminogen and casein showed a dominant PA proteolytic band (72 kDa) which co-migrated with human tPA. A proteolytic band (43 kDa), which was also secreted by FSH-stimulated cells, was not present when protection was afforded from auto-proteolysis by aprotinin, and was therefore concluded to be a proteolytic fragment of tPA, and not uPA.
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PMID:Only tissue-type plasminogen activator is secreted by immature bovine Sertoli cell-enriched cultures. 312 22

Urokinase- and tissue-type plasminogen activators (u-PA and t-PA) were identified immunohistochemically during reepithelialization of mouse and human skin wounds, by means of polyclonal and monoclonal antibodies. In incised mouse skin wounds u-PA immunoreactivity was found in keratinocytes at the edge of the wound after 12 h, and at days 2 to 10 after wounding it was found in virtually all keratinocytes of the epithelial outgrowth that gradually covered the wound. At day 14, the epidermis appeared normal and no u-PA immunoreactivity was detected. t-PA immunoreactivity was found from day 5 to day 10 in some keratinocytes located superficially in the epidermal outgrowths near the edge of the mouse wounds. In 3- and 5-day old human skin wounds, u-PA immunoreactivity was found in keratinocytes in the epithelial outgrowths, whereas no t-PA immunoreactivity was detected. No u-PA and no t-PA immunoreactivity was found in normal mouse and human epidermis. The specificity of the staining was supported by a variety of controls, including absorption of the polyclonal antibodies with highly purified u-PA and t-PA preparations and zymographic analysis of extracts of wound tissue. The function of the plasminogen activators during reepithelialization is discussed and it is suggested that the keratinocytes use plasmin activated by u-PA for dissecting their way through the provisional matrix in the upper part of the granulation tissue.
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PMID:Urokinase- and tissue-type plasminogen activators in keratinocytes during wound reepithelialization in vivo. 313 40

Ovarian follicles produce two types of plasminogen activator (tPA and uPA), and their inhibitor (PAI). We have examined the interaction and regulation of these factors in ovarian intact follicles as well as granulosa and theca-interstitial cells. The results show that only tPA, but not uPA, is regulated by the gonadotropins and reaches maximum prior to ovulation. PAI is secreted mainly by theca-interstitial cells and is stimulated also by the gonadotropins. The formation of complexes between PA and PAI completely blocks or decreases PA activity. It is suggested that the interaction between plasminogen activators and their inhibitor in the follicles may play a very important role in maintaining normal ovarian function and the machnism of ovulation.
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PMID:Interaction and regulation of plasminogen activators and their inhibitor in rat follicles during periovulatory periods. 313 65


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