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
Query: UNIPROT:P00750 (
PLA
)
16,800
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
In this study the authors attempted to restore the coagulative fibrinolytic homeostasis that is compromised in
peripheral vascular disease
. Eleven patients with arterial disease, eleven with venous disease and seven healthy volunteers underwent oral treatment using 3 g of propionyl-L-carnitine divided into thrice daily doses for a period of 20 days. (1 g t.i.d.). This quaternaria amine is able to correct tissue hypoxia by increasing ATP and energy production and has the capacity to prevent alterations in endothelial membrane permeability. The authors observed a significant increase of
t-PA
synthesis on the 10th day of therapy in the arterial disease and control groups. All three groups showed a significant increase in
t-PA
synthesis on the 20th day of therapy. A significant decrease in PAI-1 activity was observed on the 10th and on the 20th day of therapy in both the patient groups, but not in the control group. Although the exact pathological mechanisms of
peripheral vascular disease
are complex and in many aspects still unknown, it is now absolutely certain that there is a pathogenetic role of functional imbalances. An important part is played by the reduction in
t-PA
synthesis and the increase in PAI-1 activity, and the authors conclude that it is necessary to use pharmaceutical substances to restore proper equilibrium.
...
PMID:The action of propionyl-L-carnitine on the vasal endothelium: increased t-PA synthesis and a decrease in the activity of PAI-1. A preliminary study. 129 17
Low dose metformin (500 mg b.i.d.) was tested in 11 patients with symptomatic
peripheral vascular disease
(
PVD
) in an open design. At -1, 0, 1, 4, 7 months the major lipid and lipoprotein parameters, arterial function, and fibrinolytic activity were monitored. Arterial function changes were similar to those found with a high dose (850 mg t.i.d.) metformin but plasma lipids did not change to an appreciable extent. Post-ischaemic blood flow, by plethysmography, rose 30%; the exercise capacity, evaluated by treadmill test, also increased significantly by 105.7% for relative and 53.3% for absolute claudication. Total fibrinolytic activity did not change during the treatment but the antigens of two of the major components of the fibrinolytic system, i.e.
t-PA
and PAI-1, were significantly reduced at the end of the study. This study gave results quite consistent with those obtained with higher metformin doses, associated with a potentially higher risk of lactic acidosis.
...
PMID:Treatment with low dose metformin in patients with peripheral vascular disease. 173 59
Ancrod is a purified coagulant venom which renders blood incoagulable by cleaving fibrinopeptide A (FPA) from fibrinogen, but the mechanism involved in the clearance of fibrin from the circulation is unknown. To investigate the fibrinolytic response to ancrod, and to increase understanding of clearance mechanisms, six patients with
peripheral vascular disease
causing claudication were infused with ancrod at 2 u/kg over 6 h followed by 2 u/kg at 12 h intervals for 38 h. Venous blood samples were taken at time 0, 3, 6, 25 and 49 h for assay of fibrinogen (Fbg), fibrinopeptide A (FPA), total fibrin(ogen) degradation products (TDP), fibrin degradation products (FbDP), fibrinogen degradation products (FgDP), cross-linked fibrin degradation products (XL-FDP), tissue plasminogen activator (tPA), urinary type
plasminogen activator
(u-PA), plasminogen, alpha 2 antiplasmin (alpha 2 AP) and plasminogen activator inhibitor-1 (PAI-1). Fibrinogen (median and range) was 2.3 (1.4-3.90) g/l at time 0 and thereafter was undetectable. FPA rose from 2.5 (1.8-3.6) to 600 and 188 pmol/l at 3 h and 6 h and remained elevated. TDP, FbDP and FgDP increased greatly following ancrod while there was no evidence of XL-FDP. The surprising increase in FgDP during defibrination suggests either that fibrinogen is digested following its incorporation into circulating fibrin protofibrils or that some of the fibrin subunits in the photofibril retain one of the two fibrinopeptide A's. tPA and uPA remained unchanged. Plasminogen fell from 125 (100-155)% to 79 (40-118)% at 49 h and alpha 2 AP fell from 91 (75-107)% to 24 (10-35)% at 49 h. The level of PAI-1 was depressed during defibrination, with the exception of the 6 h data. The results demonstrate that ancrod removes FPA from fibrinogen to produce non-cross-linked (soluble) fibrin. This is cleared from the circulation without evidence of an increase in the circulating activities of the plasminogen activators, tPA or UK, but with evidence of plasminogen activation and consumption.
...
PMID:The fibrinolytic response to ancrod therapy: characterization of fibrinogen and fibrin degradation products. 845 76
Fibrinogen has been recognised in recent years as an independent risk factor in athero/thrombogenesis. However, the mechanism by which elevated fibrinogen translates into higher incidence of atherosclerosis is not known. One possible mechanism may be through the modification of fibrin. While it is already known that fibrin network is altered in disease states like
peripheral vascular disease
, diabetes, hypercholesterolaemia and myocardial infarction, the influence of altered fibrin network structure on growth and function of endothelial cells (EC) and fibroblasts (FB) requires investigation. Fibrin network structure in plasma clots was modified by changing pH and characterised using established biophysical methods. PGI(2), von Willebrand Factor (vWF),
t-PA
and PAI-1 were measured to evaluate changes in cell function induced by modified fibrin structure. In general, networks composed of thin fibres induced growth over their entire layer. Networks composed of thick fibres and open matrix promoted infiltration of cells into gel matrix and growth of macrovascular structures. Furthermore, thin fibres promoted a more prothrombotic environment as observed from changes in cell biochemical function. Fibrin, whilst initially acting as a scaffolding for cellular and biochemical processes, may also alter cell function and determine the progress of atherosclerosis.
...
PMID:Interaction of endothelial cells and fibroblasts with modified fibrin networks: role in atherosclerosis. 906 11
The prevention of coronary artery disease is based on the control of several factors associated with a disease or clinical condition and suspected to play a pathogenetic role, defined as 'risk factors'. Smoking is a powerful risk factor for coronary artery disease, with risk of events increasing in relation to the number of cigarettes smoked daily. Smoking cessation is associated within 3-4 years, with a significant reduction in cardiovascular risk. Hyperlipidaemia is a powerful predictor of coronary disease with a strong, independent, continuous and graded positive association between cholesterol levels and risk of coronary events. Several large studies have shown the benefit of cholesterol reduction, and there is clear evidence of the efficacy of statins in the reduction of events in primary and secondary prevention. Hypertension is a significant, strong and independent risk factor for coronary artery disease morbidity and mortality and the reduction of events and mortality by antihypertensive treatment is well documented. Obesity is associated with an increase in all-cause mortality and cardiovascular mortality, with a particularly high risk for subjects with central obesity. Central obesity is also part of the so-called 'metabolic X syndrome' including insulin resistance, which appears to be associated with a particularly high risk of coronary artery disease. Type 1 and type 2 diabetes mellitus are associated with an increased risk of cardiovascular disease, especially in women. Several studies have shown that good metabolic control and multifactorial risk factor reduction significantly lower the coronary risk in these patients. Recent evidence is accumulating that some clotting factors (fibrinogen, factor VII, von Willebrand factor) and fibrinolytic factors (
t-PA
and PAI-1) are associated with an increased risk of coronary artery disease. The European Concerted Action on Thrombosis (ECAT) showed that the levels of fibrinogen, von Willebrand factor antigen, and
t-PA
antigen are independent predictors of subsequent coronary syndromes in patients with angina pectoris, and that low fibrinogen is associated with a low risk of events despite high cholesterol levels. Post-menopausal status is associated with increased risk of coronary artery disease, particularly when menopause is premature (before the age of 45) or abrupt (surgical). There is strong, thought not yet completely definite evidence that post-menopausal hormone replacement therapy may significantly reduce the risk of events and improve survival. Hyperhomocysteinaemia is an emerging risk factor independently associated with an increased risk of coronary artery disease, cerebral vascular disease, and
peripheral vascular disease
. The administration of vitamin B6, B12 or folate seems to be useful and is currently under further evaluation. Recently, attention has been focused on the correlation between coronary artery disease and genetic factors, such as ACE gene polymorphism or the gene polymorphism for the IIIa-moiety of the platelet fibrinogen receptor IIb-IIIa. In primary prevention, control of the major risk factors mainly in patients with clustered factors will substantially reduce the risk of ischaemic events. Secondary prevention of CHD is based on: aggressive behavioural advice, blood pressure reduction in hypertensives, good metabolic control of diabetes, and cholesterol reduction. Aspirin, beta-blockers, ACE inhibitors, and oral anticoagulants, may be useful in selected patients.
...
PMID:Classical risk factors and emerging elements in the risk profile for coronary artery disease. 951 44
When urokinase was withdrawn from the market, alternative thrombolytics such as
alteplase
and
reteplase
needed to be evaluated for
peripheral vascular disease
(
PVD
). The efficacy, safety, and cost of these agents were evaluated formally by the Department of Pharmacy and presented to the Pharmacy and Therapeutics Committee. No published data support a difference in efficacy or safety between these agents. A cost analysis estimated the average total cost of care was higher for patients treated with
reteplase
($4,556) compared with
alteplase
($2,139). Therefore,
alteplase
was determined to be a more cost-effective thrombolytic agent to treat
PVD
.
...
PMID:Using efficacy, safety, and cost data to support a formulary decision regarding thrombolytic therapy. 1140 91
Tissue type
plasminogen activator
is available, through recombinant technology, for thrombolytic use as
alteplase
. Alteplase is relatively clot specific and should cause less bleeding side effects than the non-specific agents such as streptokinase. Alteplase has been used successfully in evolving myocardial infarction (MI) to reopen occluded coronary arteries. It is probably equally effective or superior to streptokinase in opening arteries and reducing mortality in MI. Alteplase is most effective when given early in MI and is probably ineffective when given 12 h after the onset of symptoms. The effectiveness of
alteplase
in MI can be increased by front loading with a bolus of 15 mg, followed by an infusion of 50 mg over 30 min and 35 mg over 60 min. Percutaneous transluminal coronary angioplasty or stenting is associated with a greater patency and lower rates of serious bleeding, recurrent ischaemia and death than
alteplase
in MI and is likely to take over from
alteplase
as the standard MI treatment. A reduced dose of
alteplase
to increase coronary artery patency prior to angioplasty may be useful in MI. An exciting new indication for the use of
alteplase
is in stroke, where it has become the first beneficial intervention. Alteplase is used to reopen occluded cerebral vessels but is associated with an increased risk of intracerebral haemorrhage. Alteplase is beneficial if given within 3 h of the onset of stroke but not after this time period. Therefore, the next challenge is to increase the percentage of people being diagnosed and treated within this period. Clinical trials have not established a role for
alteplase
in the treatment of acute coronary syndromes or deep vein thrombosis. However,
alteplase
is useful in treating pulmonary thromboembolism and
peripheral vascular disease
.
...
PMID:Alteplase: descendancy in myocardial infarction, ascendancy in stroke. 1177 4
A relationship may exist between endothelial-mediated vasodilation and
tissue-type plasminogen activator
(t-PA) release. However, the existing evidence is mainly based upon exogenous agonist administration, and needs testing under more physiological conditions. We evaluated the link between t-PA, the key fibrinolytic factor in man, and forearm reactive hyperemia, a model of endogenous endothelial-mediated vasodilation, in 13 uncomplicated hypertensive subjects and six elderly hypertensive patients with atherosclerotic
peripheral vascular disease
and hypercholesterolemia (i.e a group in whom post-ischemic hyperemia was probably defective because of dysfunctional endothelium). To characterize further the phenomenon, 29 additional uncomplicated hypertensive patients underwent intra-arterial drug infusions. Study variables were forearm blood flow (strain-gauge plethysmography), arterial and venous concentrations of t-PA mass concentrations, and calculated net release (forearm plasma flow x veno-arterial differences). Reactive hyperemia was induced by inflating a cuff midway between systolic and diastolic pressure for 10 min; blood and forearm blood flow were sampled before and after cuff release. Post-ischemic t-PA release increased in uncomplicated hypertensives, and did not change in hypercholesterolemic atherosclerotic patients in whom post-ischemic vasodilation was negligible. Local adenosine (n = 9), acetylcholine (n = 12) and bradykinin (n = 8) vasodilated similarly, but only bradykinin increased t-PA release. Thus, reactive hyperemia stimulates t-PA release, and that relationship is altered when endothelium is dysfunctional. Release of t-PA is independent of forearm vasodilatation, adenosine or biological products of muscarinic stimulation and may, perhaps, be related to the activity of the endogenous kininogen/kinin system.
...
PMID:Reactive hyperemia and tissue-type plasminogen activator release in hypertensive men. 1254 24
While there is indisputable evidence supporting the beneficial role of aerobic exercise in reducing cardiovascular risk factors, there are few dose-response studies of this relationship. Increasingly, it is thought that the cardiovascular benefits of exercise are significantly influenced by adaptations within skeletal muscle and its vasculature. However, little is known about the molecular mechanisms underlying these adaptations. To address this need, we initiated a study utilizing longitudinal, microarray-based gene expression profiling of serial skeletal muscle biopsies obtained from the study of targeted risk reduction intervention through defined exercise (STRRIDE). STRRIDE participants were overweight and exhibited symptoms characteristic of the metabolic syndrome that typically precedes type II diabetes such as insulin resistance, abnormal lipids and glucose intolerance. Expression data were statistically filtered and sorted into exercise training-responsive clusters based on gene product knowledge. One such cluster included genes that promote the degradation of fibrin clots such as
tissue plasminogen activator (t-PA)
, connective tissue activation peptide III (CTAP III) and tetranectin. The fibrinolytic activity and protein levels of tetranectin, and t-PA and its endogenous inhibitor PAI-1, were subsequently shown to change significantly in both skeletal muscle and serum in response to exercise training. Our data show that the rigors of exercise directly induce fibrinolytic genes and protein cascades, both within muscle, and in the systemic circulation. This finding is particularly significant given that the metabolic syndrome is an independent risk factor for
peripheral vascular disease
and thrombotic events within the heart and brain. We conclude that aerobic exercise training induces both local and systemic changes in fibrinolysis and vascular homeostasis that are probably protective against cardiovascular disease.
...
PMID:Skeletal muscle dictates the fibrinolytic state after exercise training in overweight men with characteristics of metabolic syndrome. 1261 18
Arterial thrombosis is a complex disorder that involves multiple genetic and environmental factors interacting to produce the characteristic phenotype. In the past decades, investigators have focused on the molecular genetics of arterial vascular disorders and have identified numerous polymorphisms and mutations in genes related to the hemostatic system and to enzymes involved in the synthesis and bioavailability of nitric oxide (NO); however, the relation between most polymorphisms and the risk of coronary artery disease, ischemic stroke, and
peripheral vascular disease
remains highly controversial. In this review, we describe the most common genetic variations involved in the pathogenesis of arterial thrombosis, their functional implications, and their association with disease risk. Specifically, we consider polymorphisms in coagulation factors (fibrinogen, prothrombin, FV Leiden, FVII, and FXIII); fibrinolytic factors (
tissue-type plasminogen activator
, plasminogen activator inhibitor-1, and thrombin-activatable fibrinolysis inhibitor); platelet surface receptors; methylenetetrahydrofolate reductase; endothelial NO synthase; and the antioxidant enzymes paraoxonase and plasma glutathione peroxidase. Overall, there seems to be a modest contribution of individual genetic variants in the hemostatic and antioxidant systems to the risk of arterial thrombosis. Thus, future research ought to focus on identifying novel genetic determinants and on the interaction of these genetic risk factors with each other and the environment to understand better the pathobiology and susceptibility to arterial thrombotic disease.
...
PMID:Genetic determinants of arterial thrombosis. 1461 95
1
2
Next >>