Platelet Factor 4 (PF4) Release during Human Platelet Aggregation in Diabetic Patients

1970 ◽  
Vol 24 (01/02) ◽  
pp. 203-205 ◽  
Author(s):  
J Chmielewski ◽  
R Farbiszewski
Keyword(s):  
Diabetes Mellitus ◽  
Platelet Aggregation ◽  
Essential Role ◽  
Human Platelet ◽  
Platelet Factor 4 ◽  
Diabetic Patients ◽  
Thromboembolic Complications ◽  
Platelet Factor ◽  
Human Platelet Aggregation

SummaryThe release of platelet factor 4 during platelet aggregation was investigated in diabetic patients. We observed an increased release of platelet factor 4 in diabetic patients.The authors suggest that the increased release of platelet factor 4 may play an essential role in pathogenesis of thromboembolic complications in diabetes mellitus.

Platelet Aggregation, β-Thromboglobulin and Platelet Factor 4 in Diabetes Mellitus and in Patients with Vasculopathy

1984 ◽  
Vol 52 (03) ◽  
pp. 236-239 ◽  
Author(s):  
J Fritschi ◽  
M Christe ◽  
B Lämmle ◽  
G A Marbet ◽  
W Berger ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Platelet Aggregation ◽  
Discriminant Analysis ◽  
Plasma Levels ◽  
Platelet Activating Factor ◽  
Platelet Factor 4 ◽  
Platelet Factor ◽  
Aggregation Response ◽  
The Difference

SummaryWe have studied 155 subjects, 48 normals, 36 diabetics without complications, 44 with complications and 27 patients with macroangiopathy. β-Thromboglobulin (β-TG) and platelet factor 4 (PF4) are elevated in the patients groups. There is no correlation between the plasma levels of β-TG and the stages of either retinopathy or macroangiopathy or nephropathy. The difference is more marked between normals and diabetics with neuropathy (p = 0.026). The aggregation response to ADP and platelet activating factor (PAF) is enhanced at lower stimulator concentration. Using the β-TG, PF4 and aggregation values the discriminant analysis allows a distinction of several subgroups especially with nephropathy and neuropathy (Table 6).

Platelet Factor 4, β-Thromboglobulin and Thrombospondin Levels in Type I Diabetes Mellitus Patients

1994 ◽  
Vol 22 (2) ◽  
pp. 90-94 ◽  
Author(s):  
M Bayraktar ◽  
S Dündar ◽  
S Kirazli ◽  
F Teletar
Keyword(s):  
Diabetes Mellitus ◽  
Type I Diabetes ◽  
Platelet Factor 4 ◽  
Type I Diabetes Mellitus ◽  
Control Group ◽  
Diabetic Patients ◽  
Type I ◽  
Platelet Factor ◽  
Release Reaction

The proteins β-thromboglobulin, platelet factor 4 and thrombospondin are stored in platelet α-granules and released from the platelet by the release reaction. The assays of these proteins were studied in patients with type I diabetes mellitus ( n = 30) and a healthy control group ( n = 15). Platelet factor 4 and β-thromboglobulin levels were not significantly different in both groups but thrombospondin concentrations in diabetic patients were significantly higher than those of the control group (136.6 ± 14.2 ng/ml vs 91.2 ± 14.3 ng/ml, P < 0.05). When the diabetic patients were divided into those with or without complications, the diabetic patients with complications ( n = 11) had significantly elevated plasma thrombospondin concentrations compared with the control group (150.4 ± 23.7 ng/ml vs 91.2 ± 14.3 ng/ml, P < 0.05), while thrombospondin concentrations in the control group were not statistically different from the diabetic patients without complications. Plasma β-thromboglobulin and platelet factor 4 levels were not significantly different between the diabetic and the control group. It is suggested that thrombospondin may be a convenient marker of in vivo platelet release reaction.

Inhibitory Effect of Staphylokinase on Platelet Aggregation

1993 ◽  
Vol 70 (05) ◽  
pp. 834-837 ◽  
Author(s):  
Akira Suehiro ◽  
Yoshio Oura ◽  
Motoo Ueda ◽  
Eizo Kakishita
Keyword(s):  
Platelet Aggregation ◽  
Human Platelet ◽  
Degradation Products ◽  
Platelet Rich Plasma ◽  
Inhibitory Effect ◽  
Effective Concentration ◽  
Inhibit Platelet Aggregation ◽  
Platelet Suspension ◽  
Washed Platelet ◽  
Human Platelet Aggregation

SummaryWe investigated the effect of staphylokinase (SAK), which has specific thrombolytic properties, on human platelet aggregation. Platelet aggregation induced with collagen was observed following preincubation of platelets in platelet-rich plasma (PRP) or washed platelet suspension (WP) with SAK at 37° C for 30 min. SAK inhibited platelet aggregation in PRP only at the highest examined concentration (1 x 10-4 g/ml). Although SAK did not inhibit platelet aggregation in WP which contained fibrinogen, it did when the platelets had been preincubated with SAK and plasminogen. The most effective concentration in WP was 1 x 10-6 g/ml. The effect could be inhibited by adding aprotinin or α2-antiplasmin. The highest generation of plasmin in the same preincubation fluid was detected at 1 x 10-6 g/ml SAK. We concluded that SAK can inhibit platelet aggregation in WP by generating plasmin and/or fibrinogen degradation products, but is only partially effective in PRP because of the existence of α2-antiplasmin.

Half-Life of Platelet Factor 4 (PF-4) in Plasma and Platelets from Macaca Mulatta

1977 ◽  
Vol 37 (01) ◽  
pp. 073-080 ◽  
Author(s):  
Knut Gjesdal ◽  
Duncan S. Pepper
Keyword(s):  
Macaca Mulatta ◽  
Half Life ◽  
Human Platelet ◽  
Gel Filtration ◽  
Platelet Factor 4 ◽  
Active Protein ◽  
Platelet Factor ◽  
Membrane Bound

SummaryHuman platelet factor 4 (PF-4) showed a reaction of complete identity with PF-4 from Macaca mulatta when tested against rabbit anti-human-PF-4. Such immunoglobulin was used for quantitative precipitation of in vivo labelled PF-4 in monkey serum. The results suggest that the active protein had an intra-platelet half-life of about 21 hours. In vitro 125I-labelled human PF-4 was injected intravenously into two monkeys and isolated by immuno-precipita-tion from platelet-poor plasma and from platelets disrupted after gel-filtration. Plasma PF-4 was found to have a half-life of 7 to 11 hours. Some of the labelled PF-4 was associated with platelets and this fraction had a rapid initial disappearance rate and a subsequent half-life close to that of plasma PF-4. The results are compatible with the hypothesis that granular PF-4 belongs to a separate compartment, whereas membrane-bound PF-4 and plasma PF-4 may interchange.

Differential Ability of Agonists to Express Distinct Pools of Fibrinogen (Gpllb/llla) Receptors which Can Mediate the Aggregation of Human Platelets

1989 ◽  
Vol 62 (03) ◽  
pp. 955-961 ◽  
Author(s):  
Ian S Watts ◽  
Rebecca J Keery ◽  
Philip Lumley
Keyword(s):  
Platelet Aggregation ◽  
Human Platelet ◽  
Surface Membrane ◽  
Blood Platelet ◽  
Human Platelets ◽  
Membrane Glycoprotein ◽  
Platelet Surface ◽  
Human Platelet Aggregation ◽  
Differential Ability ◽  
Blood Platelet Aggregation

SummaryWe have investigated the effect of two procedures that modify human platelet surface membrane glycoprotein (Gp) IIb and IIIa complexes upon whole blood platelet aggregation to a range of agonists. (A) Irreversible disruption of complexes by temporary (30 min) Ca2+-deprivation with EGTA at 37° C. (B) Binding of a monoclonal antibody M148 to the complex. EGTA exposure abolished aggregation to ADP, adrenaline and PAF. In contrast, full aggregation curves to collagen and U-46619 could still be established. EGTA exposure reduced M148 binding to platelets by 80%. Excess M148 abolished aggregation to ADP, PAF, collagen and U-46619. However, upon removal of unbound antibody from platelets full aggregation curves to collagen and U-46619 but not to ADP and PAF could be re-established. Thus human platelet aggregation to ADP, PAF and adrenaline appears absolutely dependent upon surface membrane GpIIb/IIIa complexes. In contrast, collagen and U-46619 cause expression of an additional distinct pool of Gp complexes inaccessible to EGTA and M148 in unstimulated platelets which is intimately involved in aggregation to these agonists.

Heparin Counteracts the Antiaggregating Effect of Prostacyclin by Potentiating Platelet Aggregation

1983 ◽  
Vol 49 (02) ◽  
pp. 081-083 ◽  
Author(s):  
Vittorio Bertelé ◽  
Maria Carla Roncaglioni ◽  
Maria Benedetta Donati ◽  
Giovanni de Gaetano
Keyword(s):  
Platelet Aggregation ◽  
Human Platelet ◽  
Specific Interaction ◽  
Inhibitory Effect ◽  
Effective Inhibitor ◽  
Inhibitory Potency ◽  
Human Platelet Aggregation

SummaryIt has recently been reported that heparin neutralizes the inhibitory effect of prostacyclin (PGI2) on human platelet aggregation. The mechanism of this interaction has not yet been unequivocally established. We present here evidence that heparin (Liquemin Roche) does not react directly with PGI2 but counteracts its inhibitory effect by potentiating platelet aggregation. In the absence of heparin, PGI2 was a less effective inhibitor of platelet aggregation induced by the combination of ADP and serotonin than by ADP alone. Moreover, the inhibitory effect of PGI2 was similarly reduced when increasing the concentrations of ADP (in the absence of heparin). The lack of a specific interaction between heparin and PGI2 is supported by the observation that, in the presence of heparin, other prostaglandins such as PGD2 and PGE1, and a non-prostanoid compound such as adenosine also appeared to lose their inhibitory potency. It is concluded that heparin opposes platelet aggregation inhibitory effect of PGI2 by enhancement of platelet aggregation.

Complete Covalent Structure of Human Platelet Factor 4

1979 ◽  
Vol 42 (05) ◽  
pp. 1652-1660 ◽  
Author(s):  
Francis J Morgan ◽  
Geoffrey S Begg ◽  
Colin N Chesterman
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Human Platelet ◽  
Platelet Factor 4 ◽  
Platelet Factor ◽  
Disulphide Bonds ◽  
Covalent Structure

SummaryThe amino acid sequence of the subunit of human platelet factor 4 has been determined. Human platelet factor 4 consists of identical subunits containing 70 amino acids, each with a molecular weight of 7,756. The molecule contains no methionine, phenylalanine or tryptophan. The proposed amino acid sequence of PF4 is: Glu-Ala-Glu-Glu-Asp-Gly-Asp-Leu-Gln-Cys-Leu-Cys-Val-Lys-Thr-Thr-Ser- Gln-Val-Arg-Pro-Arg-His-Ile-Thr-Ser-Leu-Glu-Val-Ile-Lys-Ala-Gly-Pro-His-Cys-Pro-Thr-Ala-Gin- Leu-Ile-Ala-Thr-Leu-Lys-Asn-Gly-Arg-Lys-Ile-Cys-Leu-Asp-Leu-Gln-Ala-Pro-Leu-Tyr-Lys-Lys- Ile-Ile-Lys-Lys-Leu-Leu-Glu-Ser. From consideration of the homology with p-thromboglobulin, disulphide bonds between residues 10 and 36 and between residues 12 and 52 can be inferred.

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