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)

There is evidence that ACE-inhibitors exert beneficial effects on endogenous fibrinolysis in patients with previous myocardial infarction. It is still unknown if this effect is restricted to this patient group only and by which mechanisms ACE-inhibitors exhibit the profibrinolytic effects. One possible explanation might be the positive influence of ACE-inhibitors on insulin metabolism by decreasing plasma insulin which in turn could decrease PAI-1, a major regulator of the fibrinolytic system. Therefore the present study examines the relationship between insulin and PAI-1 plasma levels during intravenous glucose tolerance tests before and after administration with the ACE-inhibitor lisinopril in 12 male obese patients with angiographically proven coronary artery disease and borderline hypertension. After a 4-weeks wash-out period glucose tolerance tests were performed before and after lisinopril-treatment (10mgs/d) for 12 weeks. After the treatment period, fasting plasma insulin level decreased from 15.6 +/- 2.1 to 11 +/- 1.8 uU/ml, p < or = 0.01. Stimulated levels of insulin during glucose tolerance test also significantly decreased by lisinopril (peak insulin from 57 +/- 10 to 41.2 +/- 7.3 uU/ml, p < or = 0.02). Basal plasma tissue plasminogen activator antigen, PAI-1 total antigen and PAI-1 "active" antigen were unaffected by therapy (8.4 +/- 0.5 vs 8.6 +/- 0.5 ng/ml, 118 +/- 20 vs 124 +/- 16 ng/ml and 21 +/- 7 vs 30 +/- 7 ng/ml, respectively). Our data confirm a beneficial effect of lisinopril on plasma levels of insulin but failed to demonstrate any profibrinolytic effect in this study population, thus questioning the postulated mechanism of influencing endogenous fibrinolysis by changes of plasma insulin.
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PMID:The ACE-inhibitor lisinopril affects plasma insulin levels but not fibrinolytic parameters. 883 13

Disturbances of the haemostatic system may favour the development of vascular damage and the final occlusion events in the progress of coronary heart disease (CHD). It has been shown recently in epidemiological studies, that increased concentration of several factors, mainly fibrinogen, factor VII, von Willebrand factor (vWF), and the fibrinolytic variables plasminogen activator inhibitor 1 (PAI-1) and tissue plasminogen activator (t-PA), can be considered as risk factors for CHD. As morbidity and mortality through coronary atherosclerosis are higher in type 2 diabetic patients than in nondiabetic subjects and as insulin resistance represents a situation which favours the development of atherothrombosis, evaluation of the haemostatic factors which are recognized as risk factors may be interesting to consider in these situations. In fact, it has been shown that the fibrinolytic parameters PAI-1 and t-PA antigen are strongly related to the metabolic disorder of insulin resistance, whereas the link with fibrinogen, factor VII, and vWF remains weak. Many cross-sectional studies conducted in different populations have shown that PAI-1 and t-PA antigen (which represents t-PA/PAI-1 complexes) are strongly correlated with insulin, triglyceride, high-density lipoprotein (HDL) cholesterol, body mass index, walst-to-hip ratio and blood pressure, and that the improvement of insulin resistance improves in parallel the metabolic abnormalities and the concentration of the fibrinolytic parameters. Attempts at explaining the elevated PAI-1 and t-PA antigen levels in the insulin resistance syndrome have involved many clinical and in vitro studies, in which the role of insulin, insulin propeptides, very-low-density lipoprotein (VLDL) triglyceride, insulin resistance per se, glucose, and adipose tissue have successively been analysed and the main results of these studies are presented in this review. Due to recent experimental data from animal models of thrombosis, a pathogenic role of decreased fibrinolytic activity or increased PAI-1 levels can be proposed and could play a role in the development of vascular disease in subjects with Type 2 diabetes or insulin resistance.
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PMID:Thrombogenic and fibrinolytic factors and cardiovascular risk in non-insulin-dependent diabetes mellitus. 886 93

To evaluate whether or not activated coagulation is present in the preclinical phases of type 2 diabetes mellitus, we studied 46 non-diabetic first-degree relatives of type 2 diabetic patients and 21 matched controls with no family history of diabetes. We determined the plasma levels of prothrombin fragment 1 + 2, D-dimer, fibrinogen, plasminogen activator inhibitor type 1, tissue plasminogen activator, von Willebrand factor and coagulation factors VII and VIII. Glucose tolerance, beta-cell function and insulin sensitivity were assessed in all subjects by a continuous glucose infusion of 5 mg.kg ideal body weight-1.min-1 for 60 min with model assessment of glucose, insulin and C-peptide values. Plasma levels of prothrombin fragment 1 + 2 (median 1.24 vs 0.68 nmol.l-1; P = 0.0001) and D-dimer (331 vs 254 micrograms.l-1 UEF; P = 0.018) were higher in relatives, without significant differences in the other haemostatic variables. Relatives showed higher fasting (5.5 vs 4.9 mmol.l-1, P = 0.004) and post-infusion (9.3 vs 8.3 mmol.l-1, P = 0.02) serum glucose, no differences in insulin or C-peptide levels, lower beta-cell function (122% vs 147%; P = 0.02) and no significant differences in insulin sensitivity. Fifteen relatives were glucose-intolerant and had lower beta-cell function and insulin sensitivity than glucose-tolerant relatives. Both subsets of relatives exhibited higher levels of prothrombin fragment 1 + 2 and D-dimer than control subjects. Thus, first-degree relatives of type 2 diabetic patients present an activated coagulation, even in the absence of minor degrees of glucose intolerance. These abnormalities can play a role in the pathogenesis of cardiovascular diseases frequently seen at diagnosis of type 2 diabetes.
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PMID:Increased prothrombin fragment 1 + 2 and D-dimer in first-degree relatives of type 2 diabetic patients. Prethrombotic state in relatives of type 2 diabetic patients. 887 Aug 13

The syndrome of growth hormone deficiency (GHD) in adults is associated with premature atherosclerosis, increased cardiovascular mortality, abnormal lipoprotein patterns and abnormal body composition. We have previously shown that GH-deficient adults have increased concentrations of fibrinogen and plasminogen activator inhibitor (PAI-1) activity. The aim of the present investigation was to study coagulation and fibrinolysis in 17 patients with adult-onset GHD during two years of treatment with recombinant human GH (12 micrograms/kg body weight/day). The impact of the contemporary changes in metabolic variables and body composition on coagulation and fibrinolysis was studied. The patients received conventional thyroid, adrenal and gonadal hormone replacement therapy. PAI-1 activity, PAI-1 antigen and tissue plasminogen activator (t-PA) antigen levels decreased during the GH treatment period (p < 0.05). The decrease was more pronounced in patients with high pre-treatment levels of the different variables. alpha 2-antiplasmin decreased (p < 0.05), while plasminogen was unchanged during two years of GH treatment. Fibrinogen concentrations tended to decrease after two years of GH treatment (p = 0.06), while the coagulation factors VII and VIII were unchanged. von Willebrand factor demonstrated a transient decrease after 18 months of GH treatment. The coagulation inhibitor, protein C, decreased (p < 0.05), while antithrombin was unchanged. Fasting plasma insulin increased (p < 0.01), but blood glucose did not differ after two years of GH treatment. Serum high-density lipoprotein cholesterol, total cholesterol and triglycerides were unaltered. Body fat decreased during the initial GH treatment but was unaltered after two years, while lean body mass increased (p < 0.001) and the waist over hip circumference ratio tended to decrease (p = 0.06). In conclusion, PAI-1 activity, PAI-1 antigen and t-PA antigen decreased during long-term GH treatment. These changes may be a direct effect of GH itself or may be secondary to the favourable changes in body composition. It remains to be seen whether changes in these fibrinolytic variables during rhGH treatment reduces the cardiovascular risk in patients with GHD. The present results suggest that GH plays a role in the regulation of fibrinolysis.
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PMID:Long-term treatment with growth hormone decreases plasminogen activator inhibitor-1 and tissue plasminogen activator in growth hormone-deficient adults. 888 81

The migration of arterial smooth muscle cells (SMCs) plays an important role in normal vessel development as well as the pathobiology of blood vessels. Because it is difficult to study cell migration in primates, we used ex vivo explants. The response of baboon aortic medial explants incubated in vitro in a serum-free medium with insulin and transferrin was compared with the response of whole artery injured in vivo by a balloon catheter to establish the validity of the explant model. Both the time course of entry of SMCs into the S phase and the changes in matrix metalloproteinase 9 were similar in the artery and the explants. SMCs began migrating from explants after a lag of 3 days. By day 11, > 90% of the explants exhibited SMC migration from the tissue (percent of explants with > or = 1 migrating cell). Basal migration was inhibited by antibodies to urokinase and tissue-type plasminogen activator, whereas addition of plasminogen to the explants increased migration. An inhibitor of matrix metalloproteinases. BB-94 (Batimistat), decreased migration, as did alpha 2-macroglobulin. These data demonstrate that proteinases of the matrix metalloproteinase and plasminogen/plasminogen activator families play an important role in the migration of primate arterial SMCs through the extracellular matrix.
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PMID:The role of plasminogen, plasminogen activators, and matrix metalloproteinases in primate arterial smooth muscle cell migration. 891 Dec 76

We studied tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor type 1 (PAI-1) in healthy individuals divided by smoking habit into current smokers, former smokers and non-smokers (who had never smoked). Plasma PAI-1 antigen was significantly higher in smokers than in non-smokers with intermediate levels in former smokers. A similar trend was observed for plasma PAI activity but this did not reach statistical significance. Platelet PAI-1 and plasma t-PA were not significantly different when comparing the three groups. After venous occlusion t-PA rose significantly in all groups; no significant change in plasma PAI-1 was observed. The ratio of t-PA to PAI-1 in plasma was similar in non-smokers and former smokers but lower in smokers, suggesting that there is at least partial restoration of plasma fibrinolytic potential after smoking cessation. Plasma PAI-1 antigen and PAI activity correlated with estimated pack-years of cigarettes smoked among smokers and former smokers. When all subjects were studied collectively, plasma PAI-1 correlated strongly with plasma t-PA and triglycerides: plasma t-PA also correlated strongly with triglycerdes. We conclude that chronic smoking is associated with impaired fibrinolysis in plasma and that this largely reflects elevated plasma PAI-1 in smokers. Smoking does not appear to affect the response to venous occlusion. The postulated effect of chronic smoking on plasma PAI-1 may be mediated by the influence of smoking on triglycerides and insulin resistance. Stopping smoking appears to return impaired fibrinolysis towards normal. Smoking does not quantitatively affect the platelet pool of PAI-1. Smoking habit should be controlled for in clinical analyses of PAI-1 and t-PA.
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PMID:The effects of chronic smoking on the fibrinolytic potential of plasma and platelets. 913 67

Plasma levels of lipoprotein(a) [Lp(a)], tissue plasminogen activator (tPA) and plasminogen activator inhibitor type 1 (PAI-1) were assessed in addition to anthropometry and levels of glucose, total cholesterol, triglycerides, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and apo A1 and B in 73 patients (36 men and 37 women) with primary hyperlipidaemia (group NDHL) in Kuwait. Lp(a) levels (212 mg L-1, 8-600 mg L-1, median and range) were similar to those obtained in a matched group of 32 non-insulin-dependent diabetes mellitus (NIDDM) patients with hyperlipidaemia (218 mg L-1, 50-610 mg L-1) and slightly higher, although not significantly so (P = 0.06), than levels seen in 68 healthy normolipidaemic control subjects (182 mg L-1, 70-488 mg L-1). tPA levels (8.4 ng mL-1, 3.8-18.4 ng mL-1, median and range) in group NDHL were lower than in the diabetic group (11.4 ng mL-1, 5.2-14.2 ng mL-1) but higher than in the healthy control subjects (7.4 ng mL-1, 2.8-12.6 ng mL-1). PAI-1 levels in group NDHL (40.4 ng mL-1, 8.6-55 ng mL-1, median and range) were higher than in the control subjects (32.5 ng mL-1, 14.6-46.4 ng mL-1) but lower than in diabetic patients (43.8 ng mL-1, 15.6-55 ng mL-1). Hyperlipidaemia phenotype (hypercholesterolaemia or hypertriglyceridaemia) did not influence tPA and PAI-1 levels, but Lp(a) levels were significantly lower with hypertriglyceridaemia. Gender, cigarette smoking and racial origin (Kuwaitis, other Arabs or South Asians) did not affect Lp(a), tPA and PAI-1 levels, but tPA levels were higher in postmenopausal subjects. Low-density lipoprotein (LDL) levels (whether in total cholesterol or as apo B) correlated significantly (P < 0.05) with Lp(a) levels. tPA levels were correlated with age and the plasma levels of glucose and uric acid (P < 0.05); this correlation with glucose may explain the high levels associated with diabetes, whereas the age association might account not only for the differences observed between group NDHL and the younger control group but also for the higher levels in the postmenopausal women. PAI-1 levels correlated with tPA and triglyceride (TG) levels in the groups of subjects (normo- and hyperlipidaemic). In the normolipidaemic control group, the significant associations of tPA and PAI-1 were with body mass, expressed as the body mass index or the waist-hip ratio. These results suggest that different factors influence the plasma levels of the prothrombotic factors Lp(a), tPA and PAI-1 in healthy control subjects and in patients with hyperlipidaemia. In the latter, hyperlipidaemia phenotype, age, glycaemic status and uric acid levels are important determinants of the levels of these prothrombotic variables, whereas in the healthy, young control population, body mass was the single important association with tPA and PAI-1.
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PMID:Lipoprotein(a), tissue plasminogen activator and plasminogen activator inhibitor 1 levels in hyperlipidaemic patients in Kuwait. 917 44

The purpose of this study was to examine the potential relationship of tissue plasminogen activator-plasminogen activator inhibitor-1 (tPA-PAI-1) complexes and diabetic complications in individuals with insulin-dependent diabetes mellitus (IDDM). To address this issue, data from the third follow-up visit of participants in the Epidemiology of Diabetes Complications (EDC) study were examined. There were 454 participants, aged 32 +/- 8 years, with duration of IDDM of 23 +/- 8 years. Higher levels of tPA-PAI-1 complexes were seen for both men and women with IDDM complications. Specifically, statistically significant differences were seen in men with neuropathy (1.81 +/- 0.9 versus 1.42 +/- 0.8 ng/mL, p < 0.01), microalbuminuria (1.77 +/- 1.1 versus 1.35 +/- 0.6 ng/mL, p < 0.01), retinopathy (1.67 +/- 0.9 versus 1.43 +/- 0.8 ng/mL, p < 0.05), and lower extremity arterial disease (1.93 +/- 0.7 versus 1.50 +/- 0.9 ng/mL, p < 0.05) versus men without the particular complication. In women, higher complex levels were shown for those with retinopathy (1.51 +/- 0.8 versus 1.29 +/- 1.1 ng/mL, p < 0.01). Potential mechanisms for the relationship of higher complex levels and diabetic complications include an altered fibrinolytic response and/or insulin resistance. Because the results are cross sectional, it cannot be established whether the higher concentration of complexes is a result of the presence of complications or are antecedent. Prospective follow-up will be required to determine if tPA-PAI-1 complexes are predictive of the development of IDDM complications.
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PMID:Do tissue plasminogen activator-plasminogen activator inhibitor-1 complexes relate to the complications of insulin-dependent diabetes mellitus? Pittsburgh Epidemiology of Diabetes Complications Study. 920 2

Women with polycystic ovary syndrome (PCOS) are characterized by defects in insulin action, insulin secretion, ovarian steroidogenesis, and fibrinolysis. We administered the insulin-sensitizing agent troglitazone to 13 obese women with PCOS and impaired glucose tolerance to determine whether attenuation of hyperinsulinemia ameliorates these defects. All subjects had oligomenorrhea, hirsutism, polycystic ovaries, and hyperandrogenemia. Before and after treatment with troglitazone (400 mg daily for 12 weeks), all had 1) a GnRH agonist (leuprolide) test, 2) a 75-g oral glucose tolerance test, 3) a frequently sampled iv glucose tolerance test to determine the insulin sensitivity index and the acute insulin response to glucose, 4) an oscillatory glucose infusion to assess the ability of the beta-cell to entrain to glucose as quantitated by the normalized spectral power for the insulin secretion rate, and 5) measures of fibrinolytic capacity [plasminogen activator inhibitor type 1 (PAI-1) and tissue plasminogen activator]. There was no change in body mass index (39.9 +/- 1.4 vs. 40.2 +/- 1.4 kg/m2) or body fat distribution after treatment. Both the fasting (91 +/- 3 vs. 103 +/- 3 mg/dL; P < 0.001) and 2 h (146 +/- 8 vs. 171 +/- 6 mg/dL; P < 0.02) plasma glucose concentrations during the oral glucose tolerance test declined significantly. There was a concordant reduction in glycosylated hemoglobin to 5.7 +/- 0.1 from a pretreatment level of 6.1 +/- 0.1% (P < 0.03). Insulin sensitivity increased from 0.58 +/- 0.14 to 0.95 +/- 0.26 10(-5) min-1/pmol.L (P < 0.01) after treatment as did the disposition index (745 +/- 135 vs. 381 +/- 96; P < 0.05). The ability of the beta-cell to appropriately detect and respond to an oscillatory glucose infusion improved significantly after troglitazone treatment; the normalized spectral power for the insulin secretion rate increased to 5.9 +/- 1.1 from 4.3 +/- 0.8 (P < 0.05). Basal levels of total testosterone (109.3 +/- 15.2 vs. 79.4 +/- 9.8 ng/dL; P < 0.05) and free testosterone (33.3 +/- 4.0 vs. 21.2 +/- 2.6 pg/mL; P < 0.01) declined significantly after troglitazone treatment. Leuprolide-stimulated levels of 17-hydroxyprogesterone, androstenedione, and total testosterone were significantly lower posttreatment compared to pretreatment. The reduction in androgen levels occurred independently of any changes in gonadotropin levels. A decreased functional activity of PAI-1 in blood (from 12.7 +/- 2.8 to 6.3 +/- 1.4 AU/mL P < 0.05) was associated with a decreased concentration of PAI-1 protein (from 64.9 +/- 9.1 to 44.8 +/- 6.1 ng/mL; P < 0.05). No change in the functional activity of tissue plasminogen activator (from 5.3 +/- 0.4 to 5.1 +/- 0.5 IU/mL) was observed despite a decrease in its concentration (from 9.6 +/- 0.9 to 8.2 +/- 0.7 ng/mL; P < 0.05). The marked reduction in PAI-1 could be expected to improve the fibrinolytic response to thrombosis in these subjects. We conclude that administration of troglitazone to women with PCOS and impaired glucose tolerance ameliorates the metabolic and hormonal derangements characteristic of the syndrome. Troglitazone holds potential as a useful primary or adjunctive treatment for women with PCOS.
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PMID:Troglitazone improves defects in insulin action, insulin secretion, ovarian steroidogenesis, and fibrinolysis in women with polycystic ovary syndrome. 921 80

This study was conducted to identify the mechanisms responsible for coagulative and fibrinolytic alterations and to study the effects of a short-term treatment with low-dose heparin on hemostatic abnormalities in obese non-insulin-dependent diabetes mellitus (NIDDM) patients. Four groups of age- and sex-matched patients were studied: (1) lean nondiabetic subjects (n = 30) with a body mass index (BMI) less than 25 kg/m2 (lean control subjects), (2) obese nondiabetic subjects (n = 30) with a BMI greater than 30 kg/m2 (obese control subjects), (3) lean NIDDM patients (n = 30), and (4) obese NIDDM patients (n = 30). All subjects were tested on the following parameters: fibrinogen, factor VII, prothrombin fragment 1 + 2 (F1 + 2), thrombin-antithrombin III complexes (TAT), tissue plasminogen activator (t-PA) antigen (Ag) before and after venous occlusion (VO), and plasminogen activator inhibitor type-1 (PAI-1) activity pre- and post-VO. In addition, all these parameters were evaluated in obese NIDDM patients after 10 days of treatment with a single dose of 12,500-U/d subcutaneous calcium heparin and after a 10-day washout period. At baseline, obese nondiabetic subjects, lean NIDDM patients, and especially obese NIDDM patients displayed significantly (P < .01) higher levels of fibrinogen, factor VII, F1 + 2, TAT, t-PA(Ag) pre-VO, and PAI-1 pre- and post-VO and significantly (P < .01) lower levels of t-PA(Ag) post-VO. In obese NIDDM patients treated with heparin fibrinogen, factor VII, F1 + 2, TAT, t-PA(Ag) pre-VO, and PAI-1 pre- and post-VO levels significantly (P < .01) decreased and t-PA(Ag) post-VO levels significantly (P < .01) increased at the end of treatment. Our findings demonstrate in obese nondiabetic subjects, lean NIDDM patients, and especially obese NIDDM patients the hemostatic abnormalities contributing to an enhanced risk of thrombotic complications. We conclude that in obese NIDDM patients, short-term treatment with heparin may reduce this thrombophilic state and have a potential benefit in the progression of diabetic microvascular and macrovascular disease and needs further investigation.
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PMID:Effects of heparin treatment on hemostatic abnormalities in obese non-insulin-dependent diabetic patients. 925 77


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