A Comparison of Plasma and Serum Factor VII Activity and the Formation of Tissue Thromboplastin

1962 ◽  
Vol 08 (02) ◽  
pp. 286-296
Author(s):  
P Fantl ◽  
E. C Osborn
Keyword(s):  
Human Brain ◽  
Human Plasma ◽  
Factor Vii ◽  
Brain Extract ◽  
Factor X ◽  
Similar Activity ◽  
Bovine Plasma ◽  
Tissue Thromboplastin ◽  
Species Specific ◽  
Glass Surfaces

Summary1. A mixture of human serum or plasma and bovine plasma free of factors VII and X gave, with human brain extract, identical clotting times.2. An assay of factor VII in materials low in prothrombin using human plasma euglobulin was devised.3. Factor VII isolated from human plasma or serum gave similar activity with human brain extract.4. From a preparation containing factors VII and X which was added to human brain extract in the average 31% factor VII and 25% factor X was recovered. This was not dependent on the activity of factors VII and X in the original preparation. This indicates that factors VII and X are in equilibrium with tissue thromboplastin.5. Factors VII and X are not species specific but a higher concentration of these factors is required for prothrombin conversion in a heterologous reaction mixture.6. Factor VII activity is identical in silicone-coated or uncoated glass surfaces.

scholarly journals Tissue factor-dependent activation of tritium-labeled factor IX and factor X in human plasma

Blood ◽  
1984 ◽  
Vol 63 (6) ◽  
pp. 1338-1347 ◽  
Author(s):  
SA Morrison ◽  
J Jesty
Keyword(s):  
Human Plasma ◽  
Tissue Factor ◽  
Factor Viia ◽  
Stimulate Factor ◽  
Specific Inhibitor ◽  
Factor Xa ◽  
Factor Ix ◽  
Factor Vii ◽  
Factor X ◽  
Bovine Plasma

Recent investigations have suggested that the activation of factor IX by factor VII/tissue factor may be an important alternative route to the generation of factor Xa. Accordingly, we have compared the tissue factor-dependent activation of tritium-labeled factor IX and factor X in a human plasma system and have studied the role of proteases known to stimulate factor VII activity. Plasma was defibrinated by heating and depleted of its factors IX and X by passing it through antibody columns. Addition of human brain thromboplastin, Ca2+, and purified 3H- labeled factor X to the plasma resulted, after a short lag, in burst- like activation of the factor X, measured as the release of radiolabeled activation peptide. The progress of activation was slowed by both heparin and a specific inhibitor of factor Xa, suggesting a feedback role for this enzyme, but factor X activation could not be completely abolished by such inhibitors. In the case of 3H-factor IX activation, the rate also increased for approximately 3 min after addition of thromboplastin, but was not subsequently curtailed. A survey of proteases implicated as activators of factor VII in other settings showed that both factor Xa and (to a much smaller extent) factor IXa could accelerate the activation of factor IX. However, factor Xa was unique in obliterating activation when present at concentrations greater than approximately 1 nM. Heparin inhibited the tissue factor-dependent activation of factor IX almost completely, apparently through the effect of antithrombin on the feedback reactions of factors Xa and IXa on factor VII. These results suggest that a very tight, biphasic control of factor VII activity exists in human plasma, which is modulated mainly by factor Xa. Variation of the factor IX or factor X concentrations permitted kinetic parameters for each activation to be derived. At saturation of factor VIIa/tissue factor, factor IX activation was significantly more rapid than was previously found in bovine plasma under similar conditions. The activation of factor X at saturation was slightly more rapid than in bovine plasma, despite the presence of heparin.

scholarly journals Tissue factor-dependent activation of tritium-labeled factor IX and factor X in human plasma

Blood ◽  
1984 ◽  
Vol 63 (6) ◽  
pp. 1338-1347 ◽  
Author(s):  
SA Morrison ◽  
J Jesty
Keyword(s):  
Human Plasma ◽  
Tissue Factor ◽  
Factor Viia ◽  
Stimulate Factor ◽  
Specific Inhibitor ◽  
Factor Xa ◽  
Factor Ix ◽  
Factor Vii ◽  
Factor X ◽  
Bovine Plasma

Abstract Recent investigations have suggested that the activation of factor IX by factor VII/tissue factor may be an important alternative route to the generation of factor Xa. Accordingly, we have compared the tissue factor-dependent activation of tritium-labeled factor IX and factor X in a human plasma system and have studied the role of proteases known to stimulate factor VII activity. Plasma was defibrinated by heating and depleted of its factors IX and X by passing it through antibody columns. Addition of human brain thromboplastin, Ca2+, and purified 3H- labeled factor X to the plasma resulted, after a short lag, in burst- like activation of the factor X, measured as the release of radiolabeled activation peptide. The progress of activation was slowed by both heparin and a specific inhibitor of factor Xa, suggesting a feedback role for this enzyme, but factor X activation could not be completely abolished by such inhibitors. In the case of 3H-factor IX activation, the rate also increased for approximately 3 min after addition of thromboplastin, but was not subsequently curtailed. A survey of proteases implicated as activators of factor VII in other settings showed that both factor Xa and (to a much smaller extent) factor IXa could accelerate the activation of factor IX. However, factor Xa was unique in obliterating activation when present at concentrations greater than approximately 1 nM. Heparin inhibited the tissue factor-dependent activation of factor IX almost completely, apparently through the effect of antithrombin on the feedback reactions of factors Xa and IXa on factor VII. These results suggest that a very tight, biphasic control of factor VII activity exists in human plasma, which is modulated mainly by factor Xa. Variation of the factor IX or factor X concentrations permitted kinetic parameters for each activation to be derived. At saturation of factor VIIa/tissue factor, factor IX activation was significantly more rapid than was previously found in bovine plasma under similar conditions. The activation of factor X at saturation was slightly more rapid than in bovine plasma, despite the presence of heparin.

Treatment of Tissue Thromboplastin Membranes with Phospholipase C

1973 ◽  
Vol 30 (03) ◽  
pp. 509-518 ◽  
Author(s):  
E Bjørklid ◽  
A.-B Otnæss ◽  
E Storm ◽  
H Prydz ◽  
B. V Johansen ◽  
...  
Keyword(s):  
Human Brain ◽  
Phospholipase C ◽  
Morphological Changes ◽  
Phospholipid Fraction ◽  
Enzyme Treatment ◽  
Factor Vii ◽  
Gel Chromatography ◽  
Coagulation Activity ◽  
Binding Factor ◽  
Tissue Thromboplastin

SummaryTissue thromboplastin from human brain, partially purified by extraction with deoxycholate, gel chromatography and recombination of the protein (fraction A) and phospholipid (fraction B) fractions, was examined after treatment with phospholipase C (E.C. 3.1.4.3). Various morphological changes accompanied the loss in coagulation activity caused by the enzyme. All concentrically arranged vesicles (spherulites) disappeared. Instead, a large number of quite small vesicles and many big “blebs”, probably containing diglycerides, were seen. Fused membranes appeared after treatment with the enzyme. The phospholipid fraction (fraction B) showed similar structures as thromboplastin, but not quite the same morphological changes after enzyme treatment.Phospholipase C treatment probably caused a splitting of the concentrically arranged tissue thromboplastin membranes, which spontaneously rearranged to form new vesicles or were fused to other membranes. The hydrophilic parts of the phospholipids are required for coagulation activity, either because they impart a certain ultrastructure to the membrane, or because they participate in the coagulation process in a more direct way, e.g. by forming complexes with factor VII or by binding factor VII through calcium bridges.

Effects in vitro of bovine and human antihemophilic globulins on substrate plasmas

1964 ◽  
Vol 206 (1) ◽  
pp. 74-78
Author(s):  
Philip H. Geisler ◽  
Mary F. Eichman ◽  
Leandro M. Tocantins
Keyword(s):  
Human Plasma ◽  
Normal Saline ◽  
Normal Human Plasma ◽  
Bovine Plasma ◽  
Normal Human ◽  
Species Specific

Greater clot-promoting activity has been claimed for antihemophilic globulin ( AHG) preparations from bovine plasma than for those from normal human plasma. This has been attributed to an actual higher amount of the globulin in bovine plasma. A comparison was made of the effects of bovine and human antihemophilic globulins, collected and prepared in the same manner, on the rate of clotting of not only normal and hemophilic human plasmas but on bovine plasma as well. AHG was prepared from citrated plasma by dilution, acidification, and solution of the washed precipitate in normal saline. While bovine AHG is more effective than human AHG in accelerating the clotting of normal and hemophilic human plasmas, human AHG has a greater effect on bovine plasma than does bovine AHG. Moderate dilution of the plasma substrate enhances the clot-accelerating action of the homologous AHG. The response of a plasma substrate to AHG preparations suggests the presence in plasma of species-specific antagonists which reduce the clot-promoting activity of the homologous AHG, but which are less effective against preparations from heterologous sources.

ACTIVATION OF FACTOR VII BY ASBESTOS IN BEEF PLASMA AND SERUM

1958 ◽  
Vol 36 (9) ◽  
pp. 953-958 ◽  
Author(s):  
L. G. Israels ◽  
E. Friesen ◽  
C. Sinclair
Keyword(s):  
Prothrombin Time ◽  
Human Plasma ◽  
Factor Vii ◽  
One Stage ◽  
Tissue Thromboplastin ◽  
The One

The adsorption of beef plasma on asbestos markedly shortens the one-stage prothrombin time of the plasma when tissue thromboplastin is used as the throm boplastic agent. This adsorption on asbestos does not affect the Russell viper venom time of the plasma. The adsorbed plasma exhibits increased factor VII activity over that of the original plasma. An eluate can be prepared from the asbestos which prolongs the one-stage prothrombin time sof beef and human plasma.

EXTRINSIC PATHWAY INHIBITOR (EPI) DURING ELECTUVE SUGERY : A COMPARISON WITH OTHER COAGULATION INHIBITORS

1987 ◽  
Author(s):  
P M Sandset ◽  
T R Anderson ◽  
O R Ødegaard ◽  
M L Larsen
Keyword(s):  
Potent Inhibitor ◽  
Hip Prosthesis ◽  
The Other ◽  
Factor Vii ◽  
Surgical Trauma ◽  
Factor X ◽  
Extrinsic Pathway ◽  
Heparin Cofactor Ii ◽  
Coagulation Inhibitors ◽  
Tissue Thromboplastin

Hypercoagulation after surgical trauma is probably induced by tissue thromboplastin (TP) released into the circulation. EPI, in conjuction with activated factor x (FXa), is a potent inhibitor of the IP-factor VII complex. EPI levels (chromogenic substance assay) were compared to other inhibitors; antithrombin (AT), heparin cofactor II (HCII), andprotein C (PC) in patients undergoing cholecystectomy(n=4), hip prosthesis operation (n=5),and aortic grafts operationa(n=5) Mean AT and PC levels parallelled the decrease in albumin. HCII decreased more suggesting a real consumption ofsurgery. The changes in EPI levels depended on the type ofsurgery. In hip surgery, the decline in EI levels was marked and parallelled HCII. In constrast to the other inhibitors, EPI levels stayed low over the first week after surgery:In cholecystectomy, changes were less marked and all inhibitors behaved similar. During aortic operations, EPI increased from mean 110% preoperatively to 252% peroperatively. It decreased to 86% the first day after operation. It then increased similar to the other inhibitors, but the level stayed higher than expected from the preoperative value. The patients received 3000 IU heparin peroperatively.In conclusion, hip operations produce a sustained drop in EPI activity.In aortic operations injection of heparin induced a dramatic, shortlived increase peroperatively followed by a restoration to high normal levels.

The Formation of the Extrinsic Prothrombin Activator

1961 ◽  
Vol 05 (03) ◽  
pp. 402-425 ◽  
Author(s):  
W Straub ◽  
F Duckert
Keyword(s):  
Tissue Factor ◽  
Factor Vii ◽  
Factor V ◽  
Factor X ◽  
Clotting Factors ◽  
Second Stage ◽  
Ca Ions ◽  
Tissue Thromboplastin ◽  
Congenital Factor

SummaryThe formation of the extrinsic activator of prothrombin conversion is investigated. We use the term “extrinsic activator” to avoid ambiguity which could arise when employing the name tissue thromboplastin.The experiments are carried out with purified clotting factors and congenital factor VII and X-deficient sera. Two steps can be distinguished. First, tissue factor and factor X react together as substrates in presence of Ca ions to form the extrinsic reaction product. The reaction is catalyzed enzymatically by factor VII. In the second stage, the reaction product and factor V (substrate) form the extrinsic activator which in turn can convert the prothrombin to thrombin.

Activation of Factor X

1965 ◽  
Vol 13 (02) ◽  
pp. 314-329 ◽  
Author(s):  
K Lechner ◽  
E Deutsch
Keyword(s):  
Factor Vii ◽  
Final Conclusion ◽  
Neutral Salt ◽  
Factor X ◽  
Salt Solutions ◽  
Molecular Change ◽  
Tissue Thromboplastin ◽  
Autoprothrombin C ◽  
Thromboplastin Factor ◽  
Deae Column

Summary1. Methods have been developed for the preparation of factor VII free of prothrombin and factor X, and of factor X with only a very low contamination with factor VII.2. Factors VII and X could be found with one stage methods in purified prothrombin prepared according to Seegers.3. Purified prothrombin was chromatographed on DE AE-cellulose. Two active fractions could be eluted, the first with the characteristics of Seegers’ DE AE-Prothrombin, the second with the characteristics of factor X.4. It was confirmed that DE AE-Prothrombin does not activate to thrombin in 25% citrate, and does not generate autoprothrombin C.5. The combination of both clotting active fractions coming from the DEAE-column restores the properties of non-chromatographed prothrombin.6. DE AE-cellulose chromatography of prothrombin does not induce a molecular change of prothrombin, but separates factor X from prothrombin.7. Factor X can be activated with tissue thromboplastin-factor VII or with high concentrated neutral salt solutions to a substance with the biological characteristics of autoprothrombin C.8. TAMe activity is generated in factor X preparations after incubation with tissue thromboplastin and calcium.9. Factor VII cannot be transformed into autoprothrombin C under the conditions tested.10. Factor VII is necessary for the activation of factor X with tissue thromboplastin but not with RVV.11. The amount of factor X available determines the amount of autoprothrombin C formed, whereas thromboplastin and factor VII influence the rate of the reaction.12. The final conclusion is that activated factor X is similar to or identical with autoprothrombin C.

ACTIVATION OF FACTOR VII BY ASBESTOS IN BEEF PLASMA AND SERUM

1958 ◽  
Vol 36 (1) ◽  
pp. 953-958
Author(s):  
L. G. Israels ◽  
E. Friesen ◽  
C. Sinclair
Keyword(s):  
Prothrombin Time ◽  
Human Plasma ◽  
Factor Vii ◽  
One Stage ◽  
Tissue Thromboplastin ◽  
The One

The adsorption of beef plasma on asbestos markedly shortens the one-stage prothrombin time of the plasma when tissue thromboplastin is used as the throm boplastic agent. This adsorption on asbestos does not affect the Russell viper venom time of the plasma. The adsorbed plasma exhibits increased factor VII activity over that of the original plasma. An eluate can be prepared from the asbestos which prolongs the one-stage prothrombin time sof beef and human plasma.

Sign in / Sign up

Export Citation Format

Share Document