The Basis for the Increase in Factor VIII Procoagulant Activity During Exercise

1983 ◽  
Vol 49 (01) ◽  
pp. 053-057 ◽  
Author(s):  
Robert G Kopitsky ◽  
Mary Ellen P Switzer ◽  
R Sanders Williams ◽  
Patrick A McKee
Keyword(s):  
Factor Viii ◽  
Acute Exercise ◽  
Post Exercise ◽  
Fviii Activity ◽  
Plasma Factor ◽  
The Subject ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Healthy Males ◽  
Related Increase

SummaryWe studied the effect of acute exercise on the ability of thrombin to activate plasma factor VIII (FVIII) activity in 20 healthy males. The subject showed an average exercise-related increase in FVIII activity of 54.5±8.2% over pre-exercise FVIII activity (p<0.001). When exposed to the same concentration of thrombin, post-exercise FVIII activity showed greater enhancement than pre-exercise FVIII activity: 157.1±12.8% increase in activity versus 117.3±9.9%, respectively (p<0.01). The degree of the potentiated thrombin effect in post-exercise samples relative to pre-exercise samples was linearly correlated with the degree of the exercise-related increase in FVIII activity. Taken together with our previous observations that the extent of thrombin enhancement of FVIII activity varies inversely with the mole ratio of FVIII/von Willebrand factor subunits to thrombin, these findings imply that release of FVIII does not occur during exercise, and that the exercise-related increase in FVIII activity results primarily, if not completely, from activation of already circulating but inactive FVIII.

scholarly journals Factor VIII/von Willebrand factor in subendothelium mediates platelet adhesion

Blood ◽  
1985 ◽  
Vol 65 (4) ◽  
pp. 823-831 ◽  
Author(s):  
VT Turitto ◽  
HJ Weiss ◽  
TS Zimmerman ◽  
II Sussman
Keyword(s):  
Factor Viii ◽  
Von Willebrand Factor ◽  
Vessel Wall ◽  
Platelet Adhesion ◽  
Human Factor ◽  
Rabbit Aorta ◽  
Human Factor Viii ◽  
Plasma Factor ◽  
Von Willebrand ◽  
Willebrand Factor

The present studies were undertaken to determine whether factor VIII/von Willebrand factor (vWF) present in the vessel wall (in addition to that in plasma) may mediate the attachment of platelets to subendothelium. Subendothelium from everted rabbit aorta was exposed to human citrated blood flowing through an annular perfusion chamber at 40 mL/min (wall shear rate of 2,600 s-1 for five minutes). The vessel segments were incubated at 37 degrees C for one hour with various dilutions of either goat-anti-rabbit factor VIII/vWF serum or an IgG fraction prepared from the serum. Control segments were incubated with serum or IgG from a nonimmunized goat. Values of platelet contact (C), platelet adhesion (C + S), and thrombus formation (T) on the subendothelium were evaluated by a morphometric technique. Compared with vessels incubated with fractions prepared from a normal goat, a significant decrease in platelet adhesion (C + S), ranging from 45% to 65%, was observed on vessels incubated with various dilutions (1:5 to 1:50) of either serum or IgG fractions of goat-anti-rabbit factor VIII/vWF. A similar decrease in platelet adhesion was observed with vessels incubated with an F(ab')2 fragment against rabbit factor VIII/vWF prepared in the goat. When goat-anti-rabbit factor VIII/vWF IgG was added to rabbit blood (1:75 dilution), platelet adhesion was reduced to the same extent (65%) on normal rabbit vessels and on vessels pre-incubated with goat-anti-rabbit factor VIII/vWF. Immunofluorescence studies revealed the presence of rabbit factor VIII/vWF in the subendothelium of rabbit aorta and the continued binding of the goat-anti-factor VIII/vWF antibodies on subendothelium during the perfusion studies. No uptake of human factor VIII/vWF on the rabbit subendothelium was observed by this immunologic technique; human factor VIII/vWF was found to be entirely associated with the attached human platelets. Thus, factor VIII/vWF in the vessel wall may mediate platelet attachment to subendothelium in a manner similar to that of plasma factor VIII/vWF.

scholarly journals Multimeric composition of factor VIII/von Willebrand factor following administration of DDAVP: implications for pathophysiology and therapy of von Willebrand's disease subtypes

Blood ◽  
1982 ◽  
Vol 59 (6) ◽  
pp. 1272-1278 ◽  
Author(s):  
ZM Ruggeri ◽  
PM Mannucci ◽  
R Lombardi ◽  
AB Federici ◽  
TS Zimmerman
Keyword(s):  
Factor Viii ◽  
Von Willebrand Factor ◽  
Resting State ◽  
Bleeding Time ◽  
Type I ◽  
Von Willebrand's Disease ◽  
Von Willebrand’S Disease ◽  
Plasma Factor ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract We have studied the modifications in the multimeric composition of plasma factor VIII/von Willebrand factor and the bleeding time response following administration of 1-Deamino-[8-D-arginine]-Vasopressin (DDAVP) to patients with different subtypes of von Willebrand's disease. In type I, all multimers were present in plasma in the resting state, though they were decreased in concentration. Administration of DDAVP resulted in an increased concentration of these forms as well as the appearance of larger forms than were previously present. There was concomitant correction of the bleeding time. In type IIA, large multimers were absent in the resting state, and although DDAVP induced an average threefold increase in the plasma concentration of factor VIII/von Willebrand factor, the larger multimers did not appear and the bleeding time, although shortened, was not corrected. In contrast, the larger multimers that were also absent from type IIB plasma in the resting state rapidly appeared following DDAVP administration. However, their appearance was transitory and the bleeding time, as in IIA patients, was shortened but not corrected. The characteristic multimeric composition of platelet factor VIII/von Willebrand factor in given subtypes predicted the alteration in plasma factor VIII/von Willebrand factor induced by DDAVP. These studies provide evidence that the different subtypes of von Willebrand's disease represent distinct abnormalities of factor VIII/von Willebrand factor. They also suggest that complete hemostatic correction following DDAVP can be routinely expected only in type I von Willebrand's disease, and only if factor VIII/von Willebrand factor can be raised to normal levels.

scholarly journals The mutation Arg (53)----Trp causes von Willebrand disease Normandy by abolishing binding to factor VIII. Studies with recombinant von Willebrand factor

Blood ◽  
1992 ◽  
Vol 79 (3) ◽  
pp. 563-567 ◽  
Author(s):  
S Jorieux ◽  
EA Tuley ◽  
C Gaucher ◽  
C Mazurier ◽  
JE Sadler
Keyword(s):  
Amino Acid ◽  
Factor Viii ◽  
Von Willebrand Factor ◽  
Protein Complex ◽  
Von Willebrand Disease ◽  
Cho Cell ◽  
Fviii Activity ◽  
New Variant ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract von Willebrand factor (vWF) and factor VIII (FVIII) circulate in plasma as a noncovalently linked protein complex. The FVIII/vWF interaction is required for the stabilization of procoagulant FVIII activity. Recently, we reported a new variant of von Willebrand disease (vWD) tentatively named “Normandy,” characterized by plasma vWF that appears to be structurally and functionally normal except that it does not bind FVIII. Three patients from one family were found to be homozygous for a C----T transition at codon 816 converting Arg 53 to Trp in the mature vWF subunit. To firmly establish a causal relationship between this missense mutation and vWD Normandy phenotype, we have characterized the corresponding recombinant mutant vWF(R53W). Expressed in COS-7 cells or CHO cell lines, normal vWF and vWF(R53W) were processed and formed multimers with equal efficiency. However, vWF(R53W) exhibited the same defect in FVIII binding as did plasma vWF from patients with vWD Normandy, confirming that this mutation is responsible for the vWD Normandy phenotype. These results illustrate the importance of Arg 53 of the mature vWF subunit for the binding of FVIII to vWF, and identify an amino acid residue within a disulfide loop not previously known to be involved in this interaction.

Presence Of Receptor For Activated Factor VIII On The Surface Of Released Platelets

1981 ◽  
Author(s):  
K Brodén ◽  
L-O Andersson
Keyword(s):  
Factor Viii ◽  
Von Willebrand Factor ◽  
Factor X ◽  
Factor Viii Activity ◽  
Platelet Receptor ◽  
Plasma Factor ◽  
Centrifuge Tube ◽  
Dilute Suspension ◽  
Von Willebrand ◽  
Willebrand Factor

In normal plasma Factor VIII activity is associated with a series of high molecular weight glycoprotein complexes also containing von Willebrand Factor related activities. To study the possible binding of various forms of Factor VIII to released platelets, a solution containing Factor VIII was mixed with a dilute suspension of platelets, which were released by addition of collagen. After 10 minutes of incubation the mixture was layered over 1.5 ml of 30% human serum albumin solution in a centrifuge tube and subjected to centrifugation at 7,000xg. Fractions were collected and analyzed for Factor VIII activity and phospholipid-related procoagulant activity. When purified Factor VUI/von Willebrand Factor complex was studied no significant association between the Factor VIII activity and the platelets were found. When purified Factor VUI/von Willebrand Factor complex was activated with 10-3 units/ml of thrombin and then tested, the main part of the Factor VIII activity became associated with the platelets. Even at very low platelet counts this binding was clearly detectable. The binding occurred both in the presence and in the absence of Ca2+. Thus released platelets bind thrombin-activated Factor VIII but not the Factor VUI/von Willebrand Factor complex. It is known that activation of Factor VIII by thrombin causes dissociation of the Factor VIII from the von Willebrand Factor part of the complex. The data obtained indicate that this dissociation is necessary in order to get the Factor VIII to bind to the platelet receptor. It may work as an amplification mechanism where the first traces of Thrombin formed upon initiation of coagulation dissociates Factor VIII from von Willebrand Factor, followed by binding to receptor on released platelets and formation of Factor X activator complex on the surface of the platelets.

Antifactor VIII Antibody Inhibiting Allogeneic but not Autologous Factor VIII in Patients With Mild Hemophilia A

Blood ◽  
1999 ◽  
Vol 93 (7) ◽  
pp. 2267-2273 ◽  
Author(s):  
Kathelijne Peerlinck ◽  
Marc G. Jacquemin ◽  
Jef Arnout ◽  
Marc F. Hoylaerts ◽  
Jean Guy G. Gilles ◽  
...  
Keyword(s):  
Factor Viii ◽  
Enzyme Linked Immunosorbent Assay ◽  
Type Ii ◽  
Wild Type ◽  
Mutation Site ◽  
Fviii Activity ◽  
Polyclonal Igg ◽  
Reduced Rate ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract Two unrelated patients with the same Arg2150His mutation in the factor VIII (FVIII) C1 domain, a residual FVIII activity of 0.09 IU/mL, and inhibitor titres of 300 and 6 Bethesda Units, respectively, were studied. Further analysis of patient LE, with the highest inhibitor titer, showed that (1) plasma or polyclonal IgG antibodies prepared from LE plasma inhibited the activity of allogeneic (wild-type) but not of self FVIII; (2) the presence of von Willebrand factor (vWF) increased by over 10-fold the inhibitory activity on wild-type FVIII; (3) the kinetics of FVIII inhibition followed a type II pattern, but in contrast to previously described type II inhibitors, LE IgG was potentiated by the presence of vWF instead of being in competition with it; (4) polyclonal LE IgG recognized the FVIII light chain in enzyme-linked immunosorbent assay and the recombinant A3-C1 domains in an immunoprecipitation assay, indicating that at least part of LE antibodies reacted with the FVIII domain encompassing the mutation site; and (5) LE IgG inhibited FVIII activity by decreasing the rate of FVIIIa release from vWF, but LE IgG recognized an epitope distinct from ESH8, a murine monoclonal antibody exhibiting the same property. We conclude that the present inhibitors are unique in that they clearly distinguish wild-type from self, mutated FVIII. The inhibition of wild-type FVIII by LE antibody is enhanced by vWF and is associated with an antibody-dependent reduced rate of FVIIIa release from vWF.

Antifactor VIII Antibody Inhibiting Allogeneic but not Autologous Factor VIII in Patients With Mild Hemophilia A

Blood ◽  
1999 ◽  
Vol 93 (7) ◽  
pp. 2267-2273 ◽  
Author(s):  
Kathelijne Peerlinck ◽  
Marc G. Jacquemin ◽  
Jef Arnout ◽  
Marc F. Hoylaerts ◽  
Jean Guy G. Gilles ◽  
...  
Keyword(s):  
Factor Viii ◽  
Enzyme Linked Immunosorbent Assay ◽  
Type Ii ◽  
Wild Type ◽  
Mutation Site ◽  
Fviii Activity ◽  
Polyclonal Igg ◽  
Reduced Rate ◽  
Von Willebrand ◽  
Willebrand Factor

Two unrelated patients with the same Arg2150His mutation in the factor VIII (FVIII) C1 domain, a residual FVIII activity of 0.09 IU/mL, and inhibitor titres of 300 and 6 Bethesda Units, respectively, were studied. Further analysis of patient LE, with the highest inhibitor titer, showed that (1) plasma or polyclonal IgG antibodies prepared from LE plasma inhibited the activity of allogeneic (wild-type) but not of self FVIII; (2) the presence of von Willebrand factor (vWF) increased by over 10-fold the inhibitory activity on wild-type FVIII; (3) the kinetics of FVIII inhibition followed a type II pattern, but in contrast to previously described type II inhibitors, LE IgG was potentiated by the presence of vWF instead of being in competition with it; (4) polyclonal LE IgG recognized the FVIII light chain in enzyme-linked immunosorbent assay and the recombinant A3-C1 domains in an immunoprecipitation assay, indicating that at least part of LE antibodies reacted with the FVIII domain encompassing the mutation site; and (5) LE IgG inhibited FVIII activity by decreasing the rate of FVIIIa release from vWF, but LE IgG recognized an epitope distinct from ESH8, a murine monoclonal antibody exhibiting the same property. We conclude that the present inhibitors are unique in that they clearly distinguish wild-type from self, mutated FVIII. The inhibition of wild-type FVIII by LE antibody is enhanced by vWF and is associated with an antibody-dependent reduced rate of FVIIIa release from vWF.

scholarly journals Effect of multimeric structure of the factor VIII/von Willebrand factor protein on binding to platelets

Blood ◽  
1981 ◽  
Vol 58 (2) ◽  
pp. 387-397 ◽  
Author(s):  
HR Gralnick ◽  
SB Williams ◽  
DK Morisato
Keyword(s):  
Factor Viii ◽  
Von Willebrand Factor ◽  
Competitive Inhibition ◽  
Human Platelets ◽  
Factor Vii ◽  
Variant Form ◽  
Factor Binding ◽  
Plasma Factor ◽  
Von Willebrand ◽  
Willebrand Factor

The characteristics of the intact factor VIII/von Willebrand factor protein binding to human platelets was compared to 2-mercaptoethanol- treated factor VIII/von Willebrand factor protein and to fractions of plasma factor VIII/von Willebrand factor protein that elute after the void volume. These studies indicate that the factor VIII/von Willebrand factor protein larger size oligomers bind preferentially with high affinity to low capacity sites on human platelets. The intermediate and smaller size oligomers bind with intermediate or low affinity to sites with a much greater capacity. The results from binding analysis are also paralleled by the competitive inhibition of the intact factor VIII/von Willebrand factor protein by the various 2-mercaptoethanol- treated materials. These studies indicate that the two classes of binding sites seen in previous reports of factor VII/von Willebrand factor binding reflect heterogeneity in the oligomer size of the factor VIII/von Willebrand factor protein used in these assays. This study provides a model for understanding some of the normal structure- function relationships of the normal factor VIII/von Willebrand factor protein and the defect(s) in a variant form of von Willebrand's disease. In this form of the disease, decreased factor VIII/von Willebrand factor binding to platelets is reflected in decreased von Willebrand factor activity but coagulant and/or antigen levels are normal or only slightly decreased.

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