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

The physiological variability of fibrinolytic response to 20 min upper arm venous occlusion was studied in 191 healthy women and men, 19-80 years old. It was observed that fibrinolytic response measured by the absolute amount of t-PA antigen after venous occlusion increased with increasing age (from 10.7 at 19-30 years to 25.0 ng/ml at 71-80 years), was higher in men than in women (20.9 vs 15.6 ng/ml), higher in obese than in slim subjects (29.5 vs 12.3 ng/ml) and higher in subjects with moderately elevated blood cholesterol (33.3 vs 18.2 ng/ml) and triglycerides (30.0 vs 24.4 ng/ml, all p < 0.05 or less) than in subjects with normal levels of these variables. Due to simultaneous increase in basal levels of t-PA antigen in all these cases, relative increases in t-PA antigen after venous occlusion were not altered. Fibrinolytic response measured by t-PA activity, but not with euglobulin clot lysis time, increased with age. PAI-1 antigen was not affected by venous occlusion, while PAI activity decreased to zero in most subjects (in 61-80%) regardless of age, gender or blood lipids. However, in obese subjects and especially in subjects with elevated insulin, fibrinolytic response was reduced as determined by residual PAI activity after venous occlusion (1.3 and 10.6 IU/ml, respectively) due to the increased basal level of PAI-1. It was concluded that age, gender, body weight, blood lipids and insulin significantly modulate fibrinolytic response to venous occlusion.
 ...
PMID:Fibrinolytic response to venous occlusion in healthy subjects: relationship to age, gender, body weight, blood lipids and insulin. 846 77

The increase in cardiovascular risk associated with having non-insulin-dependent diabetes mellitus (NIDDM) is far greater in women than men. Conventional risk factors do not account for this excess, and attention has focused on the possible contribution of abnormalities of fibrinolysis and coagulation in NIDDM. In the general population a number of hemostatic factors have been shown to predict the occurrence or progression of coronary artery disease. To investigate sex differences in coagulation and fibrinolysis in NIDDM, we measured levels of fibrinogen, factor VII:C, von Willebrand factor, plasminogen activator inhibitor-1, and tissue plasminogen activator in 213 NIDDM subjects (124 men and 89 women) who were not receiving insulin therapy. The women had higher levels of factor VII:C (144% versus 120.5% in men, P < .0005) and plasminogen activator inhibitor-1 activity (25.6 versus 17.0 U/mL), and these differences remained significant when account was taken of the higher body mass index (29.6 versus 28.0 kg/m2, P = .02), glycosylated hemoglobin (7.2% versus 6.8%, P < .05), and cholesterol levels (6.3 versus 5.7 mmol/L, P < .0005) in women than men. In contrast, levels of fibrinogen (3.2 versus 3.1 g/L), tissue plasminogen activator antigen (10.6 versus 11.2 ng/mL), and von Willebrand factor (1.27 versus 1.23 IU/mL) were no different between women and men, respectively. These results suggest that elevated levels of plasminogen activator inhibitor-1 and factor VII:C may contribute to the increased cardiovascular risk of NIDDM that is particularly marked in women.
 ...
PMID:Sex differences in coagulation and fibrinolysis in white subjects with non-insulin-dependent diabetes mellitus. 854 17

An increase in levels of plasma plasminogen activator inhibitor type 1 (PAI-1) is one of the main hemostatic alterations in patients with coronary heart disease. Despite growing interest in the fibrinolytic system, few studies have been undertaken to determine the effect exerted on it by the different dietary fatty acids. We investigated the effect of a monounsaturated fat (MUFA)-rich diet in comparison with a low-fat diet (National Cholesterol Education Program step 1 diet) (NCEP-1) on factors involved in blood coagulation and fibrinolysis. We also determined the effect of dietary cholesterol on these blood parameters. Twenty-one young, male, healthy volunteers followed two low-fat/high-carbohydrate diets (< 30% fat, < 10% saturated fat, 14% MUFA) for 24 days each, with 115 or 280 mg of cholesterol per 1000 kcal per day, and two oleic acid-enriched diets (38% fat, 24% MUFA) with the same dietary cholesterol as the low-fat/high-carbohydrate diets. Plasma levels of fibrinogen, thrombin-antithrombin complexes, prothrombin fragments 1+2, plasminogen, alpha 2 antiplasmin, and tissue plasminogen activator were not significantly different among the experimental diets used in this study. Consumption of the diet rich in MUFA resulted in a significant decrease in both PAI-1 plasma activity (P < .005) and antigenic PAI-1 (P < .04) compared with the carbohydrate-rich diet (NCEP-1). The addition of dietary cholesterol to each of these diets did not result in any significant additional effect. Changes in insulin levels and PAI-1 activity were positively correlated (r = .425; P < .02). In conclusion, consumption of diets rich in MUFAs decreases PAI-1 plasma activity, which is accompanied by a parallel decrease in plasma insulin levels.
 ...
PMID:Monounsaturated fatty acid-enriched diet decreases plasma plasminogen activator inhibitor type 1. 854 31

An increased risk of ischemic heart disease in men with the Lewis blood group phenotype Le(a-b-) has been reported. It has been suggested that the Le(a-b-) phenotype is a genetic marker of the insulin resistance syndrome. To examine whether Le(a-b-) confers the insulin resistance syndrome, we studied a random sample of unrelated healthy young white men and women living in Copenhagen (n = 380, 18 to 32 years). All individuals had their insulin sensitivity estimated using Bergman's minimal model (intravenous glucose in combination with tolbutamide) and systolic blood pressure (SBP) was measured with a London School of Hygiene Sphygmomanometer. A number of anthropometric measurements including body mass index (BMI, kilograms/meters squared) and biochemical characteristics were performed. The Lewis blood group typing was carried out on erythrocytes. Twenty-one men had the Le(a-b-) phenotype. Compared to all other men (N = 165), the Le(a-b-) men had a significantly higher SBP (6 mm Hg, P = .0024). They also had higher values of BMI (8%, P = .016), total body fat mass (25%, P = .015), fasting values of serum insulin (32%, P = .006), serum C-peptide (20%, P = .029), and plasma glucose (8%, P = .003). The fasting values of serum lipids, plasminogen activator inhibitor (PAI-1) activity, tissue plasminogen activator (t-PA) antigen, and insulin sensitivity did not differ between Le(a-b-) men and men with other Lewis phenotypes. Altogether 194 women participated in the study of which 21 women had the Le(a-b-) phenotype. Except for a lower PAI-1 activity (45%, P = .044), no values differed between Le(a-b-) women and women with other Lewis phenotypes. The women were also stratified according to use of oral contraceptives. Le(a-b-) women using oral contraceptives (N = 8) had a significantly lower plasma level of fasting PAI-1 activity (P = .029) and t-PA antigen (P = .004) compared to women using oral contraceptives without the Le(a-b-) phenotype (N = 42). Our data support the hypothesis that Le(a-b-) men exhibit features of the insulin resistance syndrome, including higher levels of BMI, SBP, and fasting levels of serum insulin and plasma glucose. In young women no signs of the insulin resistance syndrome were found in subjects with the Le(a-b-) phenotype.
 ...
PMID:Lewis phenotypes and the insulin resistance syndrome in young healthy white men and women. 855 28

In addition to new knowledge concerning the mechanisms whereby conventional risk factors act, other risk factors have been newly described, such as dietary antioxidants, lack of exercise, insulin resistance, excess iron stores, increased plasma angiotensin-converting enzyme, and left ventricular hypertrophy. An intact endothelium protects both by the formation of nitric oxide, which is a vasodilator and also an inhibitor of platelet aggregation and neutrophil adhesion, and by manufacturing tissue plasminogen activator. The acute thrombotic event occurs with a diurnal variation but may be precipitated by acute exertion, especially in untrained individuals, and reflects a balance between vasoconstrictory and vasodilatory stimuli from the vascular endothelium, as well as procoagulant versus anticoagulant effects of complex balancing systems. Increased risk of sudden cardiac death in the morning is thought to be a reflection of transient risk factors, such as a blood pressure increase, heart rate increase, and changes in coagulation factors, as well as changes in platelet aggregation. There is an apparent paradox between the acute effect of exercise in promoting sudden cardiac death and the chronic effect of exercise training in decreasing the risk of myocardial infarction. The explanation may be that chronic exercise training has an inhibitory effect on adrenergic discharge.
 ...
PMID:New concepts regarding events that lead to myocardial infarction. 856 63

In healthy nondiabetic women, oral contraceptives (OCs) affect hemostatic function. In diabetic women, there is concern that they may also increase the risk of diabetic vascular complications. This study was designed to examine the balance between coagulation activity and fibrinolytic activity--an indirect measure of endothelial cell function--in women with insulin-dependent diabetes mellitus (IDDM) during long-term use of OCs. The study group included 11 young women with uncomplicated IDDM who were prescribed ethinyl estradiol 30 micrograms and gestodene 75 micrograms. Twelve other diabetic women not taking OCs constituted the control group. Hemostatic function was evaluated at entry and after 1,3,6, and 12 months. In women taking OCs, plasma levels of factor VII(c) increased, while fibrinogen levels did not change. Inhibition of coagulation was affected by increased levels of protein C, although plasma levels of antithrombin III and protein S remained stable. The antigen concentrations of tissue-type plasminogen activator and plasminogen activator levels themselves were unchanged. There was a proportionate increase in the concentrations of thrombin-antithrombin III complexes and D-dimer. None of the hemostatic variables changed significantly in the control group. We conclude that the balance between coagulation activity and fibrnolysis does not change during use of this OC. Our findings suggest that low-dose OCs induce a procoagulatory state that is compensated for by enhanced fibrinolytic activity.
 ...
PMID:Balance of coagulation activity with fibrinolysis during use of oral contraceptives in women with insulin-dependent diabetes mellitus. 857 52

Hypertriglyceridemia is linked to impaired fibrinolytic function, and lipid-lowering treatment with fibric acid derivatives could hypothetically improve fibrinolysis in this condition. We therefore conducted a double-blind, placebo-controlled, crossover study of gemfibrozil treatment on fibrinolytic function in 21 men with combined hyperlipoproteinemia. Measurements were performed at rest and during mental stress and after venous occlusion. The patients had clearly disturbed fibrinolytic function, with elevated plasminogen activator inhibitor-1 (PAI-1) activity at rest ( approximately 25 U/mL; reference, <15 U/mL). Gemfibrozil reduced plasma total and VLDL cholesterol as well as all triglyceride fractions, whereas HDL cholesterol increased (P <.001 for all). Total triglyceride levels were reduced by 57 +/- 4% (from 5.3 to 2.1 mmol/L). Fasting serum insulin levels were not altered by gemfibrozil treatment. Plasma levels of PAI-1 activity and tissue-type plasminogen activator (TPA) activity or antigen were unaffected by gemfibrozil treatment both at rest and during the provocations. The levels of D-dimer, plasmin/antiplasmin complex, and fibrinogen were also uninfluenced by gemfibrozil treatment. Mental stress elevated plasma TPA (P=.0036) and lowered PAI-1 (P=.0012) activity during placebo but not gemfibrozil treatment (P=.28 and P=.17, respectively), but treatment effects did not differ by ANOVA on delta values (ie, stress minus rest). Venous occlusion reduced PAI-1 activity, whereas TPA and plasmin/antiplasmin complex increased during both treatments. Thus, gemfibrozil treatment did not improve fibrinolysis or lower fibrinogen levels in men with combined hyperlipoproteinemia despite marked reduction of plasma triglyceride levels. It seems unlikely that improved fibrinolysis explains the primary preventive effect of gemfibrozil.
 ...
PMID:Gemfibrozil treatment of combined hyperlipoproteinemia. No improvement of fibrinolysis despite marked reduction of plasma triglyceride levels. 862 72

The effect of chronic stress on tissue-type plasminogen activator (TPA) and plasminogen activator inhibitor-1 (PAI-1) antigens was studied in 69 healthy middle-aged men. Chronic stress, defined as feelings of fatigue, lack of energy, increased irritability, and demoralization, was positively associated with plasma concentrations of PAI-1 antigen but was unrelated to TPA. The association remained unaltered after controlling for age, smoking, alcohol consumption, and physical activity but became nonsignificant after further controlling for abdominal obesity, BMI, and serum insulin and triglyceride levels. This attenuated association implies that the relationship between vital exhaustion and PAI-1 may be secondary to the effects of the metabolic variables. Thus, the present study shows that long-term stress affects the fibrinolytic system and suggests that obesity and insulin and triglyceride concentrations, which are closely correlated with the fibrinolytic parameters, may mediate the association. These findings are consistent with the hypothesis that chronic stress causes increased synthesis of PAI-1, thus promoting the risk for atherothrombotic disease by decreasing the likelihood of spontaneous fibrinolysis and increasing the likelihood of fibrin deposition.
 ...
PMID:Association of chronic stress with plasminogen activator inhibitor-1 in healthy middle-aged men. 863 Jun 60

The associations between abdominal visceral fat and the plasma hemostatic system were examined in 38-year-old healthy men (n=52) with a wide range of fatness and fat distribution. Plasma hemostatic factors and metabolic parameters, including glucose tolerance, were measured, and body fatness and adipose tissue distribution were assessed by using computed tomography. The men with more visceral fat (ie, higher than the median value [n=26]) had a less favorable metabolic profile than the men with less visceral fat (n=26). They also had significantly (P<.05) higher plasma fibrinogen, factor VIII clotting activity, tissue-type plasminogen activator antigen, and plasminogen activator inhibitor-1 (PAI-1) activity (19.2+/-2.4 versus 8.5+/-1.6 AU/mL, P<.001) and lower basal tissue-type plasminogen activator activity. After adjustment for plasma insulin, the men with larger abdominal visceral fat area still had significantly higher plasma PAI-1 activity, but no difference was found in any of the other hemostatic factors. In multiple linear regression analysis, abdominal visceral fat area was a positive predictor of plasma PAI-1 activity, but it failed to show any significant association with other hemostatic factors after controlling for plasma insulin. These results suggest the presence of relationships between abdominal visceral fat and several plasma hemostatic factors that are largely mediated by concomitant alterations in plasma insulin concentration. In addition, our results suggest that abdominal accumulation of visceral fat is an independent predictor of plasma PAI-1 activity.
 ...
PMID:Visceral fat accumulation and its relation to plasma hemostatic factors in healthy men. 863 Jun 61

A possible cause of accelerated atherothrombosis in the syndrome of insulin resistance appears to be an elevated blood concentration of plasminogen activator inhibitor type-1 (PAI-1). Insulin resistance occurs with aging, attributable partly to increased adiposity. Scarce information exists regarding the effects of weight loss in elderly, obese individuals on PAI-1 concentrations. Consequently, weight loss (9 +/- 1 kg) was induced by energy intake restriction in 19 elderly, obese individuals, and its effect on fibrinolytic system peptides was measured. Initially elevated PAI-1 concentrations decreased by 50%, with a simultaneous decrease in the concentration of tissue-type plasminogen activator (t-PA)/PAI-1 complexes but no significant change in t-PA suggested a decrease in inhibition of the fibrinolytic system. The concentration of plasmin/antiplasmin complexes (PAP complex) increased by approximately 20%, indicating augmented fibrinolytic system activity. The decline in PAI-1 correlated with that of the decrease in body weight (r = 0.5, P < 0.05) and fat mass losses (r = 0.46, P < 0.05). The increase in PAP complexes correlated with weight and fat mass losses (r = 0.4 and r = 0.46, respectively; P < 0.05 for both). No correlation was seen between fibrinolytic system variables and baseline concentrations of substrates or insulin, but the change in PAI-1 correlated with the change in plasma triacylglycerols (r = 0.58, P < 0.05). Results indicate that energy restriction sufficient to induce moderate weight loss leads to diminution of elevated plasma PAI-1 and relief of inhibition of the fibrinolytic system in elderly, obese subjects. To the extent that these changes are associated with a decrease in the progression of vasculopathy, weight loss in elderly, obese individuals may be a useful means to reduce cardiovascular morbidity and mortality.
 ...
PMID:Amelioration of the inhibition of fibrinolysis in elderly, obese subjects by moderate energy intake restriction. 866 17


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>