The fibrinolytic system components are increased in systemic sclerosis and modulated by Alprostadil (alpha1 ciclodestryn)

OBJECTIVES: To evaluate urokinase plasminogen activator (u-PA), urokinase plasminogen activator soluble receptor (su-PAR), plasminogen activator inhibitor 1 (PAI-1) and tissue plasminogen activator (t-PA) plasma levels in SSc patients (pts) versus healthy controls and their modulation by intravenous alphacyclodestrine (Alprostadil). METHODS: Plasma levels of u-PA, su-PAR, PAI-1 and t-PA were measured in 40 SSc (34 lSSc and 6 dSSc) pts and in 30 healthy controls. In SSc, blood was drawn before and after 3 consecutive daily of Alprostadil infusion (60 mg in 250 cc NaCl 0.9%). RESULTS: In SSc su-PAR basal levels were higher than controls (7.48 +/- 2.5 vs 4.69 +/- 0.4 ng/ml; p = 0.001) and were significantly reduced by Alprostadil (5.93 +/- 1.7; p = 0.002), but remain higher than controls (p = 0.03). u-PA basal levels were higher than controls (3.78 +/- 1.5 vs 1.29 +/- 0.3 ng/ml; p < 0.001) and were reduced by Alprostadil (2.39 +/- 1.7; p < 0.001) to control levels. SSc PAI-1 basal levels were lower than controls (31.60 +/- 7.7 vs 48.30 +/- 6.8 ng/ml; p < 0.001) and increased by Alprostadil (34.66 +/- 5.4; p = 0.04), but lower than controls (p < 0.001). SSc t-PA basal levels were higher in respect to controls (1645.81 +/- 792.7 vs 571.95 +/- 75.5 pg/ml; p < 0.0001) and reduced by Alprostadil (1318.06 +/- 603.5; p = 0.04), but still higher than controls (p = 0.001). CONCLUSION: Fibrinolysis were increased in SSc. Infusions of Alprostadil modulate u-PA, su-PAR, PAI-1 and t-PA, restoring near normal levels. In SSc, fibrinolysis system may become a potential target for new therapies.     

The role of strict metabolic control by insulin infusion on fibrinolytic profile during an acute coronary event in diabetic patients

BACKGROUND: Many clinical and laboratory observations give support to the hypothesis that strict metabolic control by insulin infusion during acute coronary events may improve the ischemic damage and prognosis. HYPOTHESIS: We investigated the impact of intensive insulin treatment on fibrinolytic parameters during an acute ischemic myocardial event (unstable angina or acute myocardial infarction) in patients with type 2 diabetes mellitus. METHODS: The study group consisted of 48 type 2 diabetic patients, of whom 24 were randomized to conventional therapy plus intensive insulin treatment (Group 1) and 24 to conventional therapy only (Group 2). The two groups were comparable according to gender, age, body mass index, waist:hip ratio, duration of diabetes, previous antidiabetic treatment, type of ischemic events, concomitant therapy, and the classic risk factors for coronary disease. Insulin-treated patients were excluded from the study. Plasma levels of fibrinogen, tissue plasminogen activator (t-PA), and plasminogen activator inhibitor-1 (PAI-1) were measured on admission and discharge. Fibrinogen (fibr) was measured using the photometric method. PAI-1 and t-PA were measured by enzyme-linked immunosorbent assays. RESULTS: T-PA increased in both groups during hospitalization (t-PA(admission) vs. t-PA(discharge): Group 1: 15.42 +/- 4.4 ng x ml(-1) vs. 21.2 +/- 5.74 ng x ml(-1), p = 0.000037; Group 2: 14.47 +/- 6.31 ng x ml(-1) vs. 19.18 +/- 6.88 ng x ml(-1), p = 0.001). On the other hand, fibr and PAI-1 levels increased remarkably in controls (Group 2, fibr(admission) vs. fibr(discharge): 2.98 +/- 1.04 g x l(-1) vs. 3.59 +/- 1.01 g x l(-1), p = 0.002, and PAI-1admission vs. PAI-1 discharge: 30.6 +/- 17.34 ng x ml(-1) vs. 40.62 +/- 23.48 ng x ml(-1), p = 0.003). This finding was not observed in the intensive insulin treatment group (Group 1, fibr(admission) vs. fibr(discharge): 2.87 +/- 0.73 g x l(-1) vs. 2.67 +/- 0.72 g x l(-1), p = 0.101, and PAI-1 admission vs. PAI-1 discharge: 30.75 +/- 15.81 ng x ml(-1) vs. 27.75 +/- 6.43 ng x ml(-1), p = 0.484). CONCLUSION: Intensive insulin treatment during an acute coronary event improves fibrinolytic profile in patients with diabetes mellitus. This is a possible mechanism for the reduced short- and long-term mortality in diabetic patients treated with intensive insulin treatment protocol.     

Fibrinolytic activities and their relations to esophageal variceal bleeding in patients with liver cirrhosis]

BACKGROUND/AIMS: Esophageal variceal bleeding in liver cirrhosis is a major complication and has high mortality rate. We tried to find fibrinolytic parameters, which correlated with variceal bleeding in cirrhotic patients. METHODS: We divided the cirrhotic patients into two groups: bleeding group (group A, n=15) and non-bleeding group (Group B, n=17). Fibrinolytic parameters (fibrinogen, D-dimer, plasminogen, tissue plasminogen activator [t-PA], fibrin degradation product [FDP], and plasminogen activator inhibitor type-1 [PAI-1]) were compared between two groups. In the group A, serial samplings were taken at the initial period, 3 days, 8 days, 15 days and 6 weeks after the bleeding onset. RESULTS: Plasma levels of FDP and D-dimer in the group A were significantly higher than the group B (1.7 +/- 1.16 vs. 0.95 +/- 1.27 mg/L and 10.96 +/- 6.58 vs. 4.99 +/- 3.50 micro gram/mL, respectively, p value<0.05). The clinical, biochemical, and coagulation parameters didn't show significant differences in both groups. The fibrinolytic parameters were improved along with the hemodynamic stabilization in group A. CONCLUSIONS: Cirrhotic patients with increased fibrinolytic activity were at higher risk of bleeding. Thus, the measurement of these parameters would be useful to identify patients at higher risk of esophageal variceal bleeding.     

Long-term behavior of endothelial and coagulation markers in Eisenmenger syndrome.

The long-term behavior of endothelial markers was studied in patients with Eisenmenger syndrome who were subjected to conventional therapy (no vasodilators) and observed for 18 months. Biochemical markers were analyzed comparatively in patients with class II or III symptoms (group 1, n=10) and patients with class IV symptoms (group 2, n=7). Plasma von Willebrand factor antigen (vWF:Ag), thrombomodulin, tissue-type plasminogen activator (t-PA) and its inhibitor (PAI-1), and D-dimer were determined by immunoenzymatic assay at baseline, and at 6, 12, and 18 months. At baseline, the main clinical difference between groups was a decreased peripheral oxygen saturation in group 2 versus group 1 (77+/-5% and 86+/-4%, respectively, p=0.001). Basal vWF:Ag and t-PA were increased and thrombomodulin was decreased in both groups in comparison with controls (p<0.0001), while D-dimer was increased in group 2 only (p=0.0003). In response to treatment, there was a decrease in vWF:Ag in both groups (19% and 23%, respectively in groups 1 and 2, at 18 months vs. baseline, p<0.0001) and t-PA in group 1 (38% vs. baseline, p=0.0485). Plasma vWF:Ag tended to be higher in group 2 in comparison with group 1 during the whole follow-up. Levels of PAI-1 greater than 38.4 ng/mL (upper 90% limit for normals) and D-dimer greater than 500 ng/mL were detected in individual patients (both groups) during the follow-up period. Thrombomodulin remained decreased in both groups. Thus, severity of symptoms in the Eisenmenger syndrome appears to correlate with low oxygen saturation and higher vWF:Ag levels. Improvement of endothelial dysfunction may occur in response to treatment, although increased risk for thrombosis persists, in view of residual abnormalities.     

Acute hyperglycemia and acute hyperinsulinemia decrease plasma fibrinolytic activity and increase plasminogen activator inhibitor type 1 in the rat

Decreased plasma fibrinolysis may contribute to accelerated atherothrombosis in diabetes. To observe whether hyperglycemia and hyperinsulinemia, common findings in type 2 diabetes, acutely affect plasma fibrinolysis in vivo, we evaluated plasma fibrinolysis (lysis of fibrin plates, free PAI-1 activity and t-PA activity) in the rat after a hyperglycemic euinsulinemic clamp (n=8), an euglycemic hyperinsulinemic clamp (n=7) or a saline infusion (n=15). Plasma fibrinolytic activity was sharply reduced after both the hyperglycemic and hyperinsulinemic clamps as compared to the respective controls (mean lysis areas on the fibrin plate, 139+/-21 vs. 323+/-30 mm2, p<0.001; 78+/-27 vs. 312+/-27 mm2 p<0.001, respectively). Plasma PAI-1 activity was greater after both hyperglycemic and hyperinsulinemic clamps as compared to saline infusion (6.6+/-2.6 vs. 1.6+/-0.6 IU/ml, p<0.001; 26+/-4 vs. 1.3+/-0.7 IU/ml, p<0.0001, respectively). Plasma t-PA activity was significantly reduced both after the hyperglycemic (0.36+/-0.15 vs. 2.17+/-0.18 IU/ml in controls, p<0.001) and the hyperinsulinemic (0.3+/-0.1 vs. 2.3+/-0.3 IU/ml in control, p<0.001) clamps. These data show that in vivo both acute hyperglycemia and acute hyperinsulinemia can decrease plasma fibrinolytic potential and that this is due to increased plasma PAI-1 and decreased free t-PA activities.     

An increase of C-reactive protein is associated with enhanced activation of endogenous fibrinolysis at baseline but an impaired endothelial fibrinolytic response after venous occlusion

OBJECTIVES: The goal of this study was to determine whether chronic inflammation of the vascular wall may be associated with an impaired activation of the fibrinolytic system. BACKGROUND: Inflammation plays an important role in the initiation and progression of atherosclerosis, and the fibrinolytic system may prevent local thrombus formation. METHODS: We included 50 patients six months after their first myocardial infarction. Plasma levels of the inflammatory marker C-reactive protein (CRP) were determined at basal conditions, and the fibrinolytic parameters tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor type-1 (PAI-1) were measured at basal conditions and after a standardized venous occlusion (VO) of the forearm. RESULTS: Patients with high CRP levels (> or =3 mg/l) showed a significantly higher t-PA activity at baseline compared with patients with medium (1 to 2.9 mg/l) and low (<1 mg/l) CRP levels (p <0.005). In contrast, patients with low CRP levels showed a higher increase of t-PA activity (p <0.05) and a higher reduction of PAI-1 activity during VO (p <0.05) compared with patients with medium and high CRP levels. A multivariate analysis that included cardiovascular risk factors and medical treatment showed that CRP is an independent predictor of the t-PA response after a standardized VO. CONCLUSIONS: Chronic low-grade inflammation is associated with enhanced activation of endogenous fibrinolysis at baseline but a reduced fibrinolytic response to VO. This impaired endogenous fibrinolytic capacity might be an important contributor to the increased coronary event rate associated with elevated CRP levels.     

Tissue-type plasminogen activator and its inhibitor (PAI-1) in plasma in cases of non-insulin-dependent diabetes mellitus (NIDDM)

Parameters of fibrinolysis, including plasminogen, alpha 2 plasmin-inhibitor (alpha 2 PI), tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) antigens, and fibrinogen were assayed in 53 patients (28 women and 27 men; mean age: 64 years, age range: 32-87 years) with non-insulin-dependent diabetes mellitus (NIDDM). The control group was similarly aged (mean age: 60.4 years, age range: 38-81). The levels of t-PA and t-PA/PAI-1 ratio of the diabetic group (mean +/- SD; 9.8 +/- 4.3 ng/ml, 0.94 +/- 0.47, respectively) were significantly higher than that of the control group (5.5 +/- 2.5 ng/ml, 0.51 +/- 0.23, respectively). The increased levels of t-PA antigen and t-PA/PAI-1 ratio in diabetics mean that free t-PA has been released. However, there was no significant difference in the level of PAI-1 between the diabetic group (12.9 +/- 6.4 ng/ml) and the control group (12.1 +/- 5.6 ng/ml). Levels of fibrinogen, plasminogen and alpha 2 PI in plasma were not different in the two groups. Duration of the disease, levels of glycosylated hemoglobin, differences in treatment and presense of diabetic nephropathy or retinopathy did not affect the fibrinolytic parameters. The levels of fibrinogen was higher in those with nephropathy than in the diabetics without nephropathy and retinopathy (p less than 0.05). There were no significant differences in the levels of t-PA, t-PA/PAI-1 ratio and PAI-1 between younger (less than 65 years) and older (65 years or more) subjects, in either the control or diabetic groups.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effects of rosiglitazone treatment on the fibrinolytic system in patients with type 2 diabetes mellitus.

Patients with type 2 diabetes mellitus (DM) are at risk for the development of cardiovascular diseases, which can in part be explained by disturbances in the hemostatic and fibrinolytic systems. The effects of rosiglitazone treatment on the fibrinolytic system and insulin sensitivity in patients with type 2 DM were assessed. Twenty-four patients with type 2 DM and 28 healthy subjects were enrolled in the study. Plasma global fibrinolytic capacity (GFC), tissue plasminogen activator (t-PA), and plasminogen activator inhibitor-1 (PAI-1) levels were measured. Insulin resistance was calculated by hoemostasis model assessment. Patients with type 2 DM then were placed on rosiglitazone (4 mg/day, for 12 weeks) in addition coexistent medication, and baseline tests were repeated. There was no difference between mean t-PA levels of the two groups. PAI-1 levels were higher in diabetic patients than control subjects (p < 0.01). Diabetic patients had lower GFC and t-PA/PAI-1 levels than control subjects (p < 0.05, p < 0.05). PAI-1 levels were positively correlated with waist circumference in diabetic group (r = 0.4, p < 0.05). After rosiglitazone treatment, there was no difference in mean plasma levels of GFC, t-PA, PAI-1 and t-PA/PAI-1 in diabetics. Insulin sensitivity significantly improved after the addition of rosiglitazone treatment in diabetic patients (p < 0.01). The short-term and low-dose treatment with rosiglitazone in type 2 diabetic patients has no effects on the fibrinolytic system, although it improves insulin sensitivity.     

Increased plasma fibrinolysis and tissue-type plasminogen activator/tissue-type plasminogen activator inhibitor ratios after ethanol withdrawal in chronic alcoholics.

The effects of alcohol withdrawal on fibrinolysis were studied in 10 middle-aged male chronic alcoholics institutionalized for withdrawal therapy. All patients were sampled on admission [day 1 (D1)] and 21 days after alcohol withdrawal [day 22 (D22)]. The overall plasma fibrinolytic capacity (OFC) was assayed by measuring the ability of patient plasma to generate D-dimers from a standardized fibrin clot, and tissue-type plasminogen activator (t-PA) and t-PA inhibitor (PAI-1) levels were assayed together with serum cholesterol, triglyceride and cholesterol fractions. At D22, the OFC significantly increased in seven patients [D1 = 10 +/- 0.7 microg/h (mean +/- SD), D22 = 17 +/- 7.4 microg/h; P < 0.01], while t-PA and PAI-1 levels decreased in all patients but two (t-PA: D1 = 16.6 +/- 5 ng/ml, D22 = 10.2 +/- 3.8 ng/ml; P < 0.001; and PAI-1: D1 = 46 +/- 39 ng/ml, D22 = 21 +/- 28 ng/ml; P < 0.01). This study clearly demonstrates an increase in overall fibrinolytic activity after alcohol withdrawal, which is mainly due to a decrease in PAI-1 levels. These changes induced by alcohol abstinence might provide clear benefit by reducing the risk of thromboembolic events and particularly of stroke associated with elevated PAI-1 levels described in heavy drinkers.     

辛伐他汀对冠心病患者纤溶参数的影响

目的了解冠心病患者纤溶参数的变化,并观察辛伐他汀对冠心病患者纤溶参数的影响。方法测定87例正常对照者和108例冠心病患者血浆组织型纤溶酶原激活物(t-PA)活性和纤溶酶原激活物抑制物-(1PAI-1)活性,随后108例冠心病患者被随机分成常规治疗组和常规治疗+辛伐他汀40mg每日一次(辛伐他汀组)。治疗14d后复测t-PA活性和PAI-1活性。结果与正常对照组相比较,冠心病患者纤溶参数异常,t-PA活性下降,PAI-1活性上升(P<0.01)。常规治疗组治疗后纤溶参数无显著变化(P>0.05)。辛伐他汀组纤溶参数明显改善,表现为t-PA活性上升,PAI-1活性下降(P<0.01)。结论冠心病患者纤溶参数明显异常,辛伐他汀能改善冠心病患者纤溶参数。     

心力衰竭患者血浆纤溶活性指标的变化及福辛普利的干预作用

目的:探讨心力衰竭患者血浆纤溶活性指标的变化以及血管紧张素转换酶抑制剂福辛普利干预的影响。方法:58例心力衰竭患者随机分成福辛普利组30例和常规治疗组28例,福辛普利组在常规治疗基础上加用福辛普利10mg/d,入院后当天和治疗后2周采血检测血浆纤溶酶原激活剂抑制物1(PAI1)含量与活性、组织纤溶酶原激活剂(tPA)活性。选择20例健康体检者作为正常对照。结果:与健康体检者比较,心力衰竭患者血浆PAI1含量与活性升高,tPA活性降低(P均<0.01);治疗后2周福辛普利组较常规治疗组血浆PAI1含量与活性明显降低(P均<0.01),tPA活性明显升高(P均<0.01)。结论:心力衰竭时血浆纤溶活性降低,福辛普利治疗可改善其纤溶活性,对降低心力衰竭患者血栓栓塞性疾病的发生可能有重要意义。     

Gene Polymorphisms for PAI-1 Are Associated with the Angiographic Extent of Coronary Artery Disease

Localized regulation of fibrinolytic protein gene expression is associated with the histologic extent of atherosclerosis. This regulation may be dependent on the presence of certain fibrinolytic protein gene polymorphisms. The relationship between the plasminogen activator inhibitor (PAI)-1 HindIII and the tissue plasminogen activator (t-PA) EcoR1 gene polymorphisms and the extent of coronary artery disease (CAD) were investigated in 49 Caucasian patients with symptomatic CAD. There was a strong association between PAI-1, but not t-PA, gene polymorphisms and the extent of CAD detected by coronary angiography. Patients homozygous for the presence or absence of the PAI-1 HindIII (1/1, 2/2 PAI-1) gene polymorphisms had a significantly greater extent of CAD (number of diseased vessels) than patients with the respective heterozygous forms (vs. 1/2 PAI-1, P = 0.05). Stepwise ordinal multiple regression analysis of classic CAD risk factors and fibrinolytic protein genotypes indicated that only the PAI-1 genotypes were predictive of the extent of angiographic CAD (P = 0.019). Analysis of variance between classic risk factors and fibrinolytic protein genotypes identified an association between t-PA genotypes and a history of prior infarction or stroke. Fibrinolytic gene polymorphisms for PAI-1 are associated with the extent of CAD in symptomatic patients and with certain risk factors for coronary atherosclerosis.     

Characterization and fibrinolytic properties of human omental tissue mesothelial cells. Comparison with endothelial cells

It has been reported that omental fat tissue is a good source of human microvascular endothelial cells. By characterization we demonstrate that the epitheloid cells isolated from omental tissue are not endothelial cells, but mesothelial cells. They contain abundant cytokeratins 8 and 18, which are absent in endothelial cells, and vimentin. No staining with the endothelial-specific antibodies EN-4 and PAL-E is observed. A faint and diffuse staining of von Willebrand factor (vWF) is seen in mesothelial cells, whereas microvascular endothelial cells from subcutaneous fat display vWF in distinct granular structures. Human peritoneal mesothelium produces plasminogen activator-dependent fibrinolytic activity, which is essential in the resolution of fibrous exudates and may therefore be important in preventing the formation of fibrous peritoneal adhesions. This fibrinolytic activity is plasminogen activator-dependent, but has not been fully characterized. We report here that human omental tissue mesothelial cells in vitro produce large amounts of tissue-type plasminogen activator (t-PA), together with type 1 and 2 plasminogen activator inhibitor (PAI-1 and PAI-2). PAI-1 is predominantly secreted into the culture medium, whereas the major part of PAI-2 is found in the cells. No urokinase-type plasminogen activator is detected. On stimulation with the inflammatory mediator tumor necrosis factor (TNF), at least a threefold decrease in t-PA antigen is observed, together with an increase in both PAI-1 and PAI-2. TNF also induces a marked change in cell shape. Whereas TNF and bacterial lipopolysaccharide (LPS) have similar effects on the production of PA inhibitor by human endothelial cells, LPS has no or only a relatively small effect on the fibrinolytic properties of mesothelial cells. The decreased fibrinolytic activity induced by the cytokine TNF may impair the natural dissolution of fibrin deposits at the peritoneum in the presence of an inflammatory reaction.     

脑血栓形成病人血浆及脑脊液t-PA及其PAI-1含量的观察

目的：研究动脉粥样硬化性脑血栓形成病人血浆及脑脊液组织型纤溶酶原激活物（t-PA)及其抑制物（PAI-1）含量的变化及其临床意义。方法：采用双抗体夹心固相酶联免疫吸附法（ELISA）检测35例脑血栓形成病人血浆和其中31例病人脑脊液t-PA及PAI-1抗原含量，与35例正常对照组血浆和其中20例对照组脑脊液进行比较。结果；脑血栓形成组血浆t-PA含量高于对照组，PAI-1含量显著高于对照组；其脑脊液t-PA,PAI-1含量均显著高于对照组，脑脊液中t-PA,PAI-1的含量分别与血浆中t-PA,PAI-1的含量，分别与血浆中t-PA,PAI-1的含量呈正相关；脑血栓形成组病人神经功能缺损评分与血浆及脑脊液t-PA,PAI-1抗原含量呈正相关。结论：脑血栓形成病人纤溶活性明显下降，t-PA及PAI-1参与了脑血栓形成之病理过程；t-PA及PAI-1抗原含量是反映体内纤溶活性的两个重要指标；可用血浆或脑脊液t-PA,PAI-1的含量作为判断病情的参考指标之一。     

Thrombin and plasmin generation in patients with liver disease

Patients with liver disease frequently have multiple hemostatic abnormalities. Coagulation and fibrinolytic factors and inhibitors may decrease as the result of impaired synthesis and/or enhanced catabolism. In order to assess the actual degree of activation of coagulation and fibrinolytic systems in liver disease, plasma levels of thrombin-antithrombin III complex (TAT) and plasmin-alpha 2-antiplasmin complex (PAP) were measured together with cross-linked fibrin derivatives (XDP), tissue-type plasminogen activator (t-PA), and plasminogen activator inhibitor (PAI-1) in 31 patients with liver disease (five patients with acute hepatitis, seven with chronic hepatitis, nine with liver cirrhosis, and ten with hepatocellular carcinoma). Mean plasma levels of TAT (mean 4.2 +/- SD 4.0 micrograms/L), PAP (0.7 +/- 0.7 mg/L), and XDP (374 +/- 518 micrograms/L) were significantly elevated in patients with liver disease as compared with normal subjects (TAT of 1.7 +/- 0.3 micrograms/L, PAP of 0.2 +/- 0.1 mg/L, and XDP of 30 +/- 14 micrograms/L; P less than 0.005). Plasma concentrations of t-PA and PAI-1 antigens were also elevated. When plotted by the disease categories, the magnitude of elevations of these parameters was variable among subgroups. Patients with acute hepatitis had considerably higher TAT levels. The mean PAP values were relatively high in chronic hepatitis and hepatocellular carcinoma, in which an elevation of the t-PA/PAI-1 ratio was observed. Although clearance of TAT and PAP should be evaluated in the future, these findings suggest that excessive amounts of thrombin and plasmin are actually generated in patients with liver disease.     

Involvement of fibrinolytic factors in mid trimester amniotic fluid with development of severe early-onset preeclampsia

Impaired placental development is a well-known pathogenesis in preeclampsia. The present study was undertaken to elucidate the involvement of fibrinolytic factors in amniotic fluid in midtrimester with development of severe early-onset preeclampsia. Amniotic fluid was obtained by amniocentesis at 15 to 18 weeks of gestation. All specimens were retrospectively identified according to the hospital records as coming from gestations that later had severe early-onset preeclampsia (severe preeclamptic group, n = 9) or gestations with normal outcomes (control group, n = 73). Fibrinolytic factors such as tissue plasminogen activator (t-PA), plasminogen activator inhibitor type 1 (PAI-1), and t-PA-PAI-1 complex (PAI-C) of specimens were measured by enzyme-linked immunoassay. In the control group, concentrations of t-PA as well as PAI-1 in amniotic fluid remained at similar levels from 15 to 18 weeks, although PAI-1 levels were more than 10 times higher compared with t-PA levels. Levels of t-PA and PAI-1 in the severe preeclamptic group were not different from those of the control group. PAI-C levels gradually decreased from 15 through 18 weeks of gestation in the control group. PAI-C levels of the severe preeclamptic group were significantly lower than those of the control group (55.5 +/- 18.0% versus control; mean +/- standard deviation [SD], p <0.001). PAI-C, as the most specific indicator of the early stage of fibrinolytic activities, showed lower levels in midtrimester amniotic fluid in the severe preeclamptic group, suggesting fibrinolytic activities of amniotic fluid may have a significant role in the development of severe early-onset preeclampsia via impaired placental development in the latent stage of preeclampsia.     

Baseline fibrinolytic state and the risk of future venous thrombosis. A prospective study of endogenous tissue-type plasminogen activator and plasminogen activator inhibitor.

BACKGROUND. Although isolated abnormalities of plasminogen activation and inhibition have been reported among selected patients with venous thrombosis, it is unclear whether these deficiencies of fibrinolysis are important risk factors for thromboembolic disease. METHODS AND RESULTS. To evaluate whether baseline levels of endogenous tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor type 1 (PAI-1) predict the future occurrence of venous thrombosis, levels of these proteins were measured in prospectively collected plasma samples from 55 participants in the Physicians' Health Study who later developed deep venous thrombosis or pulmonary embolism and from an equal number of age- and smoking-matched control subjects who remained free of vascular disease during a mean follow-up period of 60.2 months. Overall, there were no statistically significant differences between case patients and control subjects in baseline levels of PAI-1 (50.5 versus 59.5 ng/ml, p = 0.26), t-PA (13.4 versus 13.3 ng/ml, p = 0.94), or PAI-1:t-PA ratio (6.84 versus 6.58, p = 0.82). No evidence of a threshold effect or trend was seen when these data were analyzed by increasing quartiles of PAI-1 (p = 0.73), t-PA (p = 0.62), or PAI-1:t-PA ratio (p = 0.93). These results were unchanged after multivariate analysis that simultaneously controlled for other baseline cardiovascular risk factors. CONCLUSIONS. In contrast to previous uncontrolled case series and smaller retrospective studies, these prospective data provide strong evidence that baseline fibrinolytic state, as measured by t-PA and PAI-1, does not predict the occurrence of future venous thrombosis.     

Diurnal variation of tissue-type plasminogen activator and its rapid inhibitor (PAI-1)

Previous studies have shown that overall fibrinolytic activity in blood follows a diurnal rhythm with a peak in the morning and a trough in the evening. The purpose of this study was to determine which fibrinolytic factor(s) was responsible for this diurnal rhythm. Resting and postvenous occlusion tissue-type plasminogen activator (t-PA) activity, resting t-PA antigen, and resting plasminogen activator inhibitor 1 (PAI-1) activity were measured in the morning and evening in 33 healthy men (mean age, 31 years) and in 15 patients (mean age, 57 years) with previous myocardial infarction or unstable angina. PAI-1 activity and t-PA antigen were significantly higher (p less than 0.01) in the morning compared with the evening in controls and patients. In contrast, resting t-PA activity was significantly lower in the morning (p less than 0.01) in both groups and was inversely correlated with PAI-1 activity (r = -0.57, p less than 0.0001). Postvenous occlusion t-PA activity and t-PA capacity were not significantly different between morning and evening in either group. Because t-PA antigen levels and PAI-1 activity were highest in the morning, the variation in t-PA activity was probably not due to decreased secretion of t-PA but instead to changes in the secretion of PAI-1. Our findings indicate that diurnal variations in PAI-1 activity may reduce fibrinolytic activity in the morning in healthy individuals and in patients with coronary artery disease.     

Effects of nicorandil on endogenous fibrinolytic capacity in patients with coronary artery disease.

BACKGROUND: Nicorandil is a hybrid-type anti-anginal drug that combines a K(ATP) channel opener and a nitric oxide donor. Recently the IONA study reported that nicorandil improves the prognosis of patients with stable angina pectoris. METHODS AND RESULTS: To examine the effects of nicorandil on endogenous fibrinolysis, plasma concentrations of tissue-type plasminogen activator (t-PA) antigen, type-1 plasminogen activator inhibitor (PAI-1) antigen and PAI activity were measured in consecutive 11 patients (7 men and 4 women, mean age 63 years, ranges 41-84 years) with coronary artery disease. Nicorandil (15 mg/day) was administered orally to each patient for 2 weeks. Venous blood samples were obtained from each patient before and after the administration of the drug in the early morning before eating. There were no significant changes in the plasma concentrations of t-PA (12.4+/-1.9 to 9.8+/-1.5) or PAI-1 (26.3+/-3.9 to 21.5+/-4.9) antigens (ng/ml, mean +/- SEM) before and after nicorandil administration. On the other hand, the plasma activity of PAI (IU/ml, mean +/- SEM) decreased significantly after the treatment (12.9+/-3.2 to 5.6+/-1.9, p=0.039). CONCLUSIONS: It is well known that PAI activity determines the whole fibrinolytic capacity and oral administration of nicorandil decreased PAI activity in patients with coronary artery disease. This finding suggests that nicorandil improves the fibrinolytic capacity and may reduce the risk of coronary thrombus formation in such patients.     

Acute systemic inflammation enhances endothelium-dependent tissue plasminogen activator release in men

OBJECTIVES: The purpose of this study was to investigate in vivo the effects of acute systemic inflammation on the endogenous fibrinolytic capacity in men. BACKGROUND: Systemic inflammation and endogenous fibrinolysis play a major role in the pathogenesis of coronary artery disease. Although previous studies have shown impaired endothelium-dependent vasomotor function, the effects of inflammation on the endothelial release of the fibrinolytic factor tissue plasminogen activator (t-PA) are unknown. METHODS: In a double-blind randomized placebo-controlled crossover trial, we administered a mild inflammatory stimulus, Salmonella typhi vaccine, or saline placebo to eight healthy men on two separate occasions. Six hours after vaccination, blood flow and plasma fibrinolytic variables were measured in both arms during intrabrachial infusions of bradykinin (40 to 1,000 pmol/min), acetylcholine (5 to 20 microg/min), and sodium nitroprusside (2 to 8 microg/min). RESULTS: Compared with placebo, the S. typhi vaccination caused a rise in white cell count (11.1 +/- 0.5 x10(9)/l vs. 7.9 +/- 0.8 x10(9)/l; p = 0.004) and plasma interleukin-6 concentrations (6.9 +/- 1.4 pg/ml vs. 1.6 +/- 0.4 pg/ml; p = 0.01) in addition to a significant augmentation of t-PA antigen (45 +/- 9 ng/100 ml/min at peak dose vs. 24 +/- 8 ng/100 ml/min at peak dose; p = 0.016, analysis of variance) and activity (104 +/- 15 IU/100 ml/min vs. 54 +/- 12 IU/100 ml/min; p = 0.006, analysis of variance) release during bradykinin infusion. Forearm blood flow increased in a dose-dependent manner after bradykinin, acetylcholine and sodium nitroprusside infusions (p < 0.001), but this was unaffected by vaccination. CONCLUSIONS: Our results showed that acute systemic inflammation augmented local forearm t-PA release in men, which suggests that acute inflammation may invoke a protective response by enhancing the acute endogenous fibrinolytic capacity in healthy men. Further studies are needed to clarify whether this response is impaired in patients with cardiovascular disease.