Levels of platelet factor 3 in citrate plasma and in whole blood as determined by a chromogenic peptide substrate assay

1979 ◽  
Author(s):  
H Sandberg ◽  
A.-K. Gellerbring ◽  
L.-O. Andersson

A newly developed sensitive method for determination of platelet factor 3 (PF 3) using a chromogenic substrate (S 2238) (Sandberg and Andersson, Thromb. Res., in press) was used for comparison of the PF 3 levels in platelet-rich plasma (PRP) in citrate with the levels in PRP in the anticoagulant EDTA/citrate/PGE 1/theophylline. It was shown that in citrate PRP, release of PF 3 was started after about 20 minutes from blood sampling. Release of β-thromboglobulin (β-tg) was found to occur simultaneously with the release of PF 3. No release of PF 3 or β-tg could be detected within 3 hours from blood sampling in PRP in the EDTA/citrate/PGE 1/theophylline anticoagulant.The PF 3 level in whole blood was measured by a method which was a modification of the method used for plasma samples. It was found that, using the same donor, the PF 3 level of plasma and blood in the EDTA/citrate/PGE 1/theophylline anticoagulant was essentially the same. The levels of PF 3 found in blood upon standing in citrate or in EDTA/citrate/PGE 1/theophylline anticoagulant were in accordance with the levels found in plasma. Experiments with whole blood without any anticoagulant showed that release of PF 3 begin to occur simultaneously with release of β-tg, about 5 minutes before clotting. Thus the data show that PF 3 and β-tg are released in parallel.

1979 ◽  
Author(s):  
H. Sandberg ◽  
A.-K. Gellerbring ◽  
L.-O. Andersson

A newly developed sensitive method for determination of platelet factor 3 (PF 3) using a chromogenic substrate (S 2238) (Sandberg and Andersson, Thromb. Res., in press) was used for comparison of the PF 3 levels in platelet-rich plasma (PRP) in citrate with the levels in PRP in the anticoagulant EDTA/citrate/PCE 1/theophylline. It was shown that in citrate PRP, release of PF 3 was started after about 20 minutes from blood sampling. Release of β-thromboglobulin (β-tg) was found to occur simultaneously with the release of PF 3. No release of PF 3 or β-tg could be detected within 3 hours from blood sampling in PRP in the EDTA/citrate/PCE 1/theophylline anticoagulant.The PF 3 level in whole blood was measured by a method which was a modification of the method used for plasma samples. It was found that, using the same donor, the PF 3 level of plasma and blood in the EDTA/citrate/PCE 1/theophylline anticoagulant was essentially the same. The levels of PF 3 found in blood upon standing in citrate or in EDTA/citrate/PCE 1/theophy11ine anticoagulant were in accordance with the levels found in plasma. Experiments with whole blood without any anticoagulant showed that release of PF 3 begin to occur simultaneously with release of β-tg, about 5 minutes before clotting. Thus the data show that PF 3 and βtg are released in parallel.


1980 ◽  
Vol 18 (6) ◽  
pp. 871-882 ◽  
Author(s):  
H. Sandberg ◽  
A.-K. Gellerbring ◽  
L.-O. Andersson

1988 ◽  
Vol 59 (02) ◽  
pp. 162-163 ◽  
Author(s):  
R R Taylor ◽  
J Strophair ◽  
M Sturm ◽  
R Vandongen ◽  
L J Beilin

SummaryThe aggregation/adhesion response to platelet activating factor (PAF) was studied in diluted whole blood by impedance aggregometry. The extent of aggregation varied directly with the interval between blood sampling and aggregation measurement over the first 30 minutes from sampling, then remained stable for the next 60 minutes of observation. This is an effect opposite to that described for aggregation to PAF in platelet rich plasma which, however, cannot be studied soon after sampling. Time dependence of aggregation is important and comparative measurements should be made during the period of stable aggregability.


1973 ◽  
Vol 30 (01) ◽  
pp. 093-105 ◽  
Author(s):  
C.H.J Sear ◽  
L Poller ◽  
F.R.C Path

SummaryThe antiheparin activity of normal serum has been studied by comparing the antiheparin activities of sera obtained from normal whole blood, platelet-rich plasma and platelet-’free’ plasma with a purified platelet extract during differential isoelectric precipitation and by gel filtration chromatography.The mean values for the activity of PRP-serum and PFP-serum were 106% (S.D. 11) and 10% (S.D. 3) of untreated whole blood respectively. The activity of whole blood serum, PRP serum and whole blood serum plus platelet extract precipitated under identical physical conditions, i.e. pH 7.0, I =0.008, indicating that the activities of the three samples are probably associated with PF4. PF4 precipitated from human platelet extract at pH 4.0, but this is probably due to the difference in the two biochemical environments investigated, i.e. serum and platelet extract.The gel filtration experiments revealed striking similarities between the major antiheparin activities of serum and platelet extract. At physiological pH and ionic strength both activities were associated with high molecular weight material, but at physiological pH and elevated ionic strength both activities behaved as much smaller entities of molecular weight between 25,000 and 30,000 daltons and it seems very likely that both activities are associated with the same molecule, i.e. PF4.


2021 ◽  
Author(s):  
Pengpeng Zhang ◽  
Liu Shuai ◽  
Shuang Yang ◽  
Yuanhong Wang ◽  
Ting-Fu Jiang ◽  
...  

A simple and sensitive method for the simultaneous determination of chito-oligosaccharide (COS) with degrees of polymerization(DPs)from 2 to 7 was developed and used for COS quantification in rat plasma. Samples...


1979 ◽  
Author(s):  
R.L. Henry ◽  
R.M. Nalbandian ◽  
G.E. Herman ◽  
T. Ho

Platelet factor four (PF4) and beta-thromboglobulin (βTG) were released from human platelets alpha granules by ADP and epinephrine and measured by radioimmunoassay. Both release materials are antiheparins but PF4 is reported to be more potent. However, PF4 is released at about 1/4 the level of βTG in nanog rams/ml. Total release occurred with 5 ugm/rnl ADP in platelet-rich-plasma adjusted to 200,000 platelets/mm3 and with 1.25 × 10-5M epinephrine. No further release was found by freeze-thawing procedures. In one case, no release occurred although full aggregation proceeded normally with both mediators. Only minimal amounts were recorded after freeze-thawing indicating a storage pool deficiency of PF4 and βTG in an apparantly normal individual. Complete inhibition of PF4 and βTG release was obtained concurrently with elimination of the 2nd epinephrine wave by 6.4 × 10-4 M Piracetam. In contrast to aspirin, no inhibition of ADP, Collagen, or Ristocetin aggregation or release occurred with Piracetam. In previous work it was determined that Piracetam even at 6.4 × 10-3 M did not modify thrombin, prothrombin, or activated partial thromboplastin times. In addition, clot retraction was not modified in concentrations of Piracetam as high as 1.28 × 10-2 M known to eliminate the 2nd wave of platelet aggregation by epinephrine.


1979 ◽  
Author(s):  
J.J.C. Jonker ◽  
L.H.M. van Riel ◽  
M.M.P. Paulssen

An automated method was developed for the determination of thrombin generation in citrated whole blood during activation by thromboplastin. The thrombin generated was allowed to split the chromogenic substrate Tos-Gly-Pro-Arg-pNA yielding p-Nitroaniline. The comparison with this method and “Prothrombin time” in 50 samples was significant (r = 0,88 P < 0,001) and also in 503 samples with “Thrombotest” (r = 0,73 P < 0,001). This assay may serve as a specific, precise and fast and cheaper alternative for “prothrombin time” and “Thrombotest” in large Thrombosis Services.


1978 ◽  
Vol 24 (7) ◽  
pp. 1155-1157 ◽  
Author(s):  
S G Chakrabarti ◽  
D A Gooray ◽  
J A Kenney

Abstract A rapid and sensitive method is described for determining 8-methoxypsoralen in plasma. Plasma samples are acidified with 6 mol/liter and heated in a boiling water bath to release the plasma-bound drug nondestructively. It then is extracted into a solvent mixture consisting of benzene/ethyl acetate (9/1 by vol). The solvent phase is separated, evaporated, and an aliquot of the dissolved residue is thin-layer chromatographed, with benzene/ethyl acetete (9/1) as developing solvent. The plate is dried and the spots, made visible under ultraviolet light (320-400 nm), are scanned. The smallest amount detectable is 20 ng; the overall analytical recovery from plasma is 84%. We used the method to determine the drug in the plasma of rabbits after intravenous and oral administration of 10 mg, and in one patient after an oral dose of 30 mg.


1975 ◽  
Author(s):  
P. Friberger ◽  
G. Axelsson ◽  
K. Korsan-Bengtsen

Plasmin splits the chromogenic substrate B2-Phe-Val-Arg-pNA (S-2160, Bofors) at a relatively high rate. Standard plasmin in glycerol obtained from Nat. Inst, for Biol. Stand, and Contr., London, was tested in a system with Tris buffer of varying pH and ionic strength. The pH optimum for the reaction was found to be 7.4. Variations in ionic strength between 0.05–0.1 had insignificant influence but at higher ionic strength there was a slight inhibition. A linear relationship was found between plasmin and AOD/min. At optimum pH and a final substrate concentration of 0.2 mM 0.1 CTA unit corresponds to approximately 0.10 nkat. Purified plasminogen (AB Kabi, Stockholm, Sweden) in the concentrations 0.02–0.2 CU/ml was activated optimally with streptokinase (Kabikinase® ) in the concentrations 500–2000 IU/ml. Higher concentration gave inhibition. The activity of streptokinase activated plasminogen increased with a decreasing ionic strength. A linear relationship was found between streptokinase activated plasminogen and AOD/min. Approximately 3,000 Plong/units per ml of urokinase was needed to obtain the same activation as with optimal streptokinase concentration. The method has been used for determination of plasminogen in plasma. With final dilution of plasma in the range 1/20–1/200 activated by streptokinase (2000 IU/ml) in a system of pH 8.2, I = 0.05, a linear relationship was found between plasma dilution and AOD/min. The reproducibility in a series of tests is good (variation coefficient < 3%) and with insignificant interference by inhibitors. The determinations were easily carried out in a simple spectrometer (405 nm) and in an automatic reaction rate analyzer (LKB 8600, 410 nm).


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