Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00750 (PLA)
 16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of grafting segments of femoral vein in the dog have been studied. The venous segments, either reversed or left in situ, were interposed in the course of the femoral artery; these 'arterialized grafts' were compared with a segment of vein grafted into the venous stream, with normal femoral artery and vein. Histological changes and alterations in fibrinolytic activity were studied after 15, 30 and 90 days. The two types of arterialized venous graft showed similar aspects: normal endothelium (scanning electron microscopy and F VIII immunofluorescence), marked thickening of the smooth muscle cell layer, disappearance of intimal fibrinolytic activity (Todd's technique, quantified by morphometric analysis), associated with a marked increase of antiplasmin activity (Noordhoek Hegt's technique), increase in the activity of vascular plasminogen activator (measured with chromogenic substrates). The venous grafts in the venous stream showed no changes compared to the normal femoral vein. The proliferation of smooth muscle cells following exposure of a segment of vein to arterial conditions appears to be associated with increased synthesis of both an inhibitor of fibrinolysis (antiplasmin), and of vascular plasminogen activator. The contribution of these two factors to the development of the morphological changes in the vessel requires further study.
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PMID:Fibrinolytic activity in experimental vascular grafts. 687 52

Haemostatic measurements were undertaken in 132 patients diagnosed with heat stroke during the pilgrimage to Makkah, in two successive summers of 1989-90. The control group comprised 49 patients, all pilgrims, with a wide range of clinical conditions, but without hyperpyrexia or deranged haemostasis. Heat stroke patients showed (i) significant prolongation of the prothrombin (PT), activated partial thromboplastin (aPTT) and thrombin times (TT) but normal reptilase time (RT); (ii) significant reduction in plasma levels of antithrombin III (AT-III), factor V, proteins C and S, plasminogen activator inhibitor (PAI) and platelet count; (iii) increase in plasma factor VIII, tissue plasminogen activator (t-PA) and serum FDP; (iv) no significant changes in plasma fibrinogen, plasminogen, alpha 2-antiplasmin and factors VII and X. Heat stroke patients were then grouped into those with and those without bleeding symptoms. Bleeders showed greater prolongation of the PT, aPTT and TT and significant reductions in fibrinogen, AT-III, factors V, VIII and X, plasminogen, alpha 2-antiplasmin and platelet count. Logistic regression and discriminant analysis showed that AT-III was the parameter associated most with heat stroke and reliable enough to predict its occurrence, whether or not bleeding occurred. The results indicate that activation of the haemostatic mechanism, consumptive in nature, regularly accompanies heat stroke and highlights the physiological role of AT-III in checking this activation process.
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PMID:The coagulopathy of heat stroke: alterations in coagulation and fibrinolysis in heat stroke patients during the pilgrimage (Haj) to Makkah. 786 79

The aim of this study was to compare the secretory response of the vascular wall in vivo to DDAVP (i.v. 0.3 microgram/kg, 30 min) and to venous occlusion (VO, 20 min) in control healthy subjects, patients with von Willebrand's disease type I (vWd I) and patients with von Willebrand's disease type III (vWd III). In controls (n = 10) and vWd I (n = 12), DDAVP induced a 2 to 3-fold rise in plasma von Willebrand factor antigen (vWf: Ag), factor VIII coagulant activity (VIII: C) and tissue--type plasminogen activator antigen (t-PA:Ag). VO was less effective in increasing vWf: Ag and VIII:C but produced a greater rise in t-PA:Ag. Large increments (over 10-fold) were observed in plasmin-alpha 2-antiplasmin complexes following both stimuli. In vWd III (n = 10), DDAVP and VO failed to increase vWf:Ag, VIII:C and t-PA:Ag. No significant changes in plasmin-alpha 2-antiplasmin complexes were observed in this group. Moreover, the baseline t-PA:Ag values were significantly lower in vWd III (2.17 +/- 1.13 ng/ml) than in controls (4.84 +/- 1.97 ng/ml, p < 0.001). A significant increase in urokinase--type plasminogen activator antigen (u-PA:Ag) was found only in controls after VO. Neither controls nor patients with vWd showed any changes in plasma fibronectin levels following DDAVP. The low t-PA:Ag results and the abnormal fibrinolytic response to DDAVP and VO in patients with severe (type III) vWd indicate that their endothelial cell abnormality is more extensive than the defect in the synthesis or release of vWf.
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PMID:Secretory response of the vessel wall to DDAVP and venous occlusion in von Willebrand's disease. 799 99

The first generation high-dose ( 80 mcg estrogen) oral contraceptives (OCs) were associated with an increased risk of deep venous thrombosis (DVT). So manufacturers removed the high-dose OCs and first replaced them with OCs with 50 mcg estrogen, resulting in a lower incidence of thromboembolic events (40 vs. 20/100,000 users). When they introduced an even lower dose OC (30 mcg estrogen), the incidence fell further (about 8/100,000 users). Yet, women using the lowest-dose OCs still have DVT more often than do control women. Life-style, age, and smoking may be confounding factors, however. It is not clear whether loss of endogenous ovarian steroid production or the effects of the orally administered contraceptive steroids cause significant changes in hemostatic factors (antithrombin III, protein S, protein C, plasminogen, tissue-type plasminogen activator, plasminogen activator inhibitor 1, histidine-rich glycoprotein, and VII, VIII, X, XII coagulation factors) during OC use. These changes tend to be within normal ranges. There is some doubt that these changes have any clinical significance. In nonsmokers, increased activity of anticoagulant factors and fibrinolytic factors counteract the effects on coagulation factors. Progestin-only OCs appear to affect hemostasis but have not increased the risk of thrombosis. There are considerable differences between people in pharmacokinetics and pharmacodynamics of contraceptive steroids. These differences may account for the increased risk of thromboembolic events in some people. Further research should identify methods of individualizing the dose of contraceptive steroids for a single patient. It should also explore the close interrelationship between hemostasis and lipid metabolism, carbohydrate metabolism, and hypertension in the development of cardiovascular disease in OC users. Providers should discourage women with a past history of DVT from using hormonal contraception.
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PMID:Coagulation and anticoagulation effects of contraceptive steroids. 817 1

Patients with end-stage renal disease (ESRD) are at risk of ischemic cardiovascular complications and vascular thrombosis. These observations prompted the present survey of the blood coagulation, fibrinolytic, and inhibitory proteins in a group of 31 ESRD patients and 32 normal controls. Immunologic and functional assays were used to quantitate plasma antigen concentrations and/or functional activities of factors XII, XI, IX, VIII, VII, X, II, and XIII, von Willebrand factor, fibrinogen, fibronectin, high molecular weight kininogen, D-dimer, antithrombin III, protein C, protein S, plasminogen, tissue-type plasminogen activator, plasminogen activator inhibitor, alpha 2-antiplasmin, alpha 1-antitrypsin, and alpha 2-macroglobulin as well as antiplasmin activity. The coagulant activities of factors XII, IX, X, and II were significantly reduced in ESRD patients despite their normal or increased plasma antigen concentrations. In addition, the ESRD patients showed hyperfibrinogenemia and significant elevations of plasma concentrations of D-dimer, von Willebrand factor, factor VII, and factor XIII antigens. They also exhibited significant reductions of antithrombin III, free protein S, plasminogen, and tissue-type plasminogen activator concentrations. Despite ultrafiltration, plasma factor IX activity and von Willebrand factor and fibrinogen concentrations decreased after hemodialysis with little or slight changes in other measured parameters. The ESRD patients studied here exhibited numerous abnormalities of coagulation, fibrinolytic, and inhibitory proteins at multiple levels. These abnormalities may be involved in the pathogenesis of cardiovascular complications and vascular thrombosis in this population. The precise mechanism(s) and clinical significance of the observed abnormalities are unknown and await further investigation.
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PMID:Blood coagulation, fibrinolytic, and inhibitory proteins in end-stage renal disease: effect of hemodialysis. 820 65

The levels of plasma tissue-type plasminogen activator (tPA), plasminogen activator inhibitor (PAI), VIII factor related antigen (VIIIR:Ag) and anti-thrombin (AT-III) were determined in 40 hypertensive patients with Blood Stasis. The results indicated that the function of coagulation-fibrinolytic system was disturbed. After one year of practising Qigong, plasma PAI and VIII R:Ag levels were decreased, while plasma tPA and AT-III levels increased. It suggested that Qigong could improve the function of coagulation-fibrinolytic system.
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PMID:[Effect of qigong on plasma coagulation fibrinolysis indices of hypertensive patients with blood stasis]. 825 25

Protein C (PC) is an anticoagulant protein which, being activated by thrombin, degrades factors V/Va and VIII/VIIIa and releases a tissue-type plasminogen activator. Some Agkistrodon snake venoms contain PC activators which, in experiments, exert an anticoagulant action. An antithrombotic effect of the PC activator from the venom of A. blomhoffi ussuriensis on the model of thrombus formation in the arterio-venous shunt in rats was under investigation. Administration of the PC activator resulted in a dose-dependent prolongation of the thrombus formation time and a decrease in plasma PC activity, which were accompanied by a decrease in factor V activity and APTT prolongation. No reliable changes in the t-PA level, ADP- and epinephrine-induced platelet aggregation were observed. Platelet adhesion to glass beads diminished. We assume that the antithrombotic effect of the PC activator from the A. blomhoffi venom in the platelet-dependent thrombosis model is caused by PC activation and subsequent factor V inactivation as well as by platelet adhesiveness reduction.
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PMID:Protein C activator from the venom of Agkistrodon blomhoffi ussuriensis retards thrombus formation in the arterio-venous shunt in rats. 837 94

Comparative study was performed on the Heart-Qi Deficiency and Blood Stasis type (HQDBS) of hypertensive patients treated with Qigong. The results showed that the clinical symptoms alleviated, cardiac morphology and function, hemorheology and erythrocyte deformity were improved. After one year of practicing Qigong, plasma histofibrinogen activation inhibitor (PAI) and VIII factor related antigen (VIII R: Ag) levels decreased, while plasma tissue fibrinolytic activator (t-PA) and anti-thrombogen III (AT-III) levels increased. Capillary blood velocity of nailfold microcirculation raised from 0.2940 +/- 0.0206 mm/s to 0.3045 +/- 0.0236 mm/s, the diameter and length of afferent limb tended to increase. The above data indicated that Qigong could benefit HQDBS. This might be the mechanism by which HQDBS type of hypertension was treated.
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PMID:[Effect of qigong on heart-qi deficiency and blood stasis type of hypertension and its mechanism]. 858 Jun 89

During acute exercise both coagulant and fibrinolytic potential increase. Since strenuous exertion is associated with an enhanced risk for cardiac events, especially in untrained individuals, it is important to determine whether the initial haemostatic balance is maintained during exercise. Twenty-nine sedentary males (20-30 years) were subjected to a standardized cycle ergometer test. Blood samples were obtained at two exercise levels, 70% VO2max (submaximal), 100% VO2max (maximal) and during 25 min recovery. Both during submaximal and maximal performance, tissue type plasminogen activator antigen, urokinase plasminogen activator antigen and tissue type plasminogen activator activity were increased. A concomitant enhancement of clotting activity of factors VII, VIII, IX, XII and fibrinogen resulted in a shortening of clotting times. Following correction for changes in plasma volume, the results for factor VII:c were reversed, and factor XII:c and fibrinogen no longer demonstrated exercise-related changes. Increases in coagulant (activated partial thromboplastin time) and fibrinolytic (tissue type plasminogen activator activity) potential proceeded in parallel during exercise. However, during recovery while there was a sustained increase in coagulant potential, fibrinolytic potential demonstrated a sharp fall. We conclude that during physical activity, while parallel changes in coagulant and fibrinolytic activity occur, this haemostatic balance is not maintained during recovery. This phenomenon could constitute an enhanced risk for coronary artery thrombosis which may contribute to exercise-related cardiovascular events.
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PMID:Unbalanced haemostatic changes following strenuous physical exercise. A study in young sedentary males. 868 38

To elucidate the possible role of plasminogen activator (PA) in spermatogenesis and spermiation in mammals, we studied the hormonal regulation of PA secretion in cultured rat and mouse seminiferous tubules during defined stages of spermatogenesis. Results indicated that: (1) under basal conditions, segments of rat seminiferous tubules released primarily urokinase-type PA (uPA) at all stages of the cycle. The highest level of PA secretion occurred at stages VIIab, VIIcd and VIII. FSH, 8-bromo cyclic AMP and forskolin (FK) stimulated PA secretion, predominantly tissue-type PA (tPA). (2) In contrast, mouse seminiferous tubules secreted only tPA under basal conditions. In the presence of 50 microM MIX, seminiferous tubules at stages VII and VIII secreted higher levels of both types of PA than at the other stages. Both tPA and uPA secretion was enhanced by addition of FSH and FK to the organ culture media. (3) Segments of both rat and mouse seminiferous tubules at stages IX-XII in which the sperm residual bodies are absorbed into the Sertoli cells were also very sensitive to the addition of FSH to the organ culture. These results suggest that tPA in rat and mouse testes may play an essential role in the process of spermatogenesis and spermiation as well as in sperm residual body absorption.
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PMID:Hormonal regulation of plasminogen activator in rat and mouse seminiferous epithelium. 872 Jun 90


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