S21.3. Platelet-activating factor increases adhesion of sickle erythrocytes to vascular endothelium by a vascular integrinαβ and von Willebrand factor-dependent mechanism

Biorheology ◽  
1995 ◽  
Vol 32 (2-3) ◽  
pp. 185-185 ◽  
Author(s):  
D KAUL ◽  
H TSAI ◽  
R NAGEL ◽  
D CHEN
Keyword(s):  
Von Willebrand Factor ◽  
Vascular Endothelium ◽  
Platelet Activating Factor ◽  
Sickle Erythrocytes ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Dependent Mechanism

Desmopressin testing in children with von Willebrand syndrome in haemostaseologic centers of Saxonia, Saxonia-Anhalt and Thuringia

2009 ◽  
Vol 29 (S 01) ◽  
pp. S98-S102 ◽  
Author(s):  
B. Huhn ◽  
A. Hofmann ◽  
K. Hofmann ◽  
H. Sirb ◽  
V. Aumann ◽  
...  
Keyword(s):  
Partial Response ◽  
Factor Viii ◽  
Von Willebrand Factor ◽  
Vascular Endothelium ◽  
Test Performance ◽  
Coagulation Factor ◽  
Syndrome Type ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryThe influence of desmopressin on hemostasis is mediated by the release of von Willebrand factor and of coagulation factor VIII from vascular endothelium. The necessity of testing desmopressin effectiveness on hemostasis is a matter of controversy and the performance of the test is not yet standardized. For this reason the desmopressin tests in 114 children with von Willebrand syndrome (type 1, n=98; type 2A, n=12; type 2M, n=2; type 2N, n=2) carried out in 7 paediatric haemostaseologic centers were retrospectively analyzed. The effectiveness of desmopressin was assessed using defined response criteria. As expected, the test performance showed a wide variation among the centers. In 99 children desmopressin was given intravenously as a short infusion at a dosage ranging from 0.25 to 0.41 μg/kg and in 15 intranasally at an absolute dose of 40 to 300 μg. The points of time for blood taking after desmopressin application ranged from 0.5 to 12 h. The absent desmopressin response in 7 patients (6%) and the partial response in 15 indicate the necessity of testing desmopressin effectiveness before the first therapeutic use. The application of desmopressin was well tolerated by the patients.

The Simultaneous Acute Release of Tissue-Type Plasminogen Activator and von Willebrand Factor in the Perfused Rat Hindleg Region

1990 ◽  
Vol 63 (03) ◽  
pp. 454-458 ◽  
Author(s):  
N Tranquille ◽  
J J Emeis
Keyword(s):  
Plasminogen Activator ◽  
Von Willebrand Factor ◽  
Time Course ◽  
Platelet Activating Factor ◽  
Calcium Ionophore ◽  
Tissue Type ◽  
Tissue Type Plasminogen Activator ◽  
Type Plasminogen Activator ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryIn perfused rat hindlegs, platelet-activating factor and bradyki-nin induced the acute release of both tissue-type plasminogen activator (t-PA) and von Willebrand Factor (vWF). The time course of release was similar for both proteins, and the amounts of t-PA and vWF released under various conditions were closely correlated. Release of both t-PA and vWF required extracellular calcium, and could be induced by the calcium ionophore A-23187. Protein synthesis was not required for release to occur.Phorbol myristate acetate also induced release of t-PA and vWF, though with a different time course; DDAVP was inactive.The results suggest that the release of t-PA, and that of vWF, are closely linked at the cellular level.

The Role of Cyclic Nucleotides in the Release of Tissue-Type Plasminogen Activator and von Willebrand Factor

1993 ◽  
Vol 69 (03) ◽  
pp. 259-261 ◽  
Author(s):  
N Tranquille ◽  
J J Emeis
Keyword(s):  
Plasminogen Activator ◽  
Von Willebrand Factor ◽  
Cyclic Nucleotides ◽  
Atrial Natriuretic Factor ◽  
Platelet Activating Factor ◽  
Tissue Type ◽  
Tissue Type Plasminogen Activator ◽  
Type Plasminogen Activator ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryThe modulation of the induced acute release of tissue-type plasminogen activator (t-PA) and of von Willebrand factor (vWF) by compounds affecting cyclic nucleotide levels was studied, using an isolated rat hindleg perfusion system. Platelet-activating factor (PAF; 5 nM) or bradykinin (0.8 (μM) were used to induce release of t-PA and vWF.The guanylate cyclase activators sodium nitroprusside and atrial natriuretic factor reduced the induced release of t-PA and vWF. Release was not affected by inhibiting nitric oxide production with NG-nitro-L-arginine. The effects of nitroprusside and atrial natriuretic factor could not be reproduced by infusion of 8-bromo-cGMP.The adenylate cyclase activator forskolin had no effect on bradykinin-induced release of t-PA and vWF, reduced PAF-induced t-PA release, but potentiated PAF-induced vWF release. These modulatory effects were only partially mimicked by infusion of 8-bromo-cAMP.None of the compounds tested was able to induce the release of t-PA or of vWF in the absence of stimulation by bradykinin or platelet-activating factor. Cyclic nucleotides can thus modulate, but not induce, the acute release of t-PA and vWF from perfused rat hindlegs.

Sign in / Sign up

Export Citation Format

Share Document