Immune Reactions of Human Blood Platelets

1968 ◽  
Vol 20 (03/04) ◽  
pp. 336-344 ◽  
Author(s):  
Ch Mueller-Eckhardt ◽  
E. F Lüscher

SummaryThe effect on human platelets of 2 endotoxin preparations (one had known Shwartzman-activity in rabbits, the other was not tested for its biological activity) was investigated in vitro. The following results were found:1. Endotoxin has no effect on washed human platelets suspended in isotonic, plasmafree buffer solution.2. Aggregation or release of adenine nucleotides from human platelets by endotoxin does also not occur if the platelets are suspended in coagulable, complement active, pooled human plasma or plasma fractions.3. Platelets pretreated with α-chymotrypsin do not show aggregation or release of nucleotides by endotoxin.4. The ability of human platelets to retract a fibrin clot is not disturbed by endotoxin. This excludes a functional platelet injury by endotoxin not detectable by aggregation or nucleotide release.5. There is no evidence for the assumption that the effect of endotoxin on platelets is transmitted by yet hypothetical, platelet-damaging mediator substances from leukocytes.6. These results suggest that an immunological injury of platelets by endotoxin comparable with the effect of immune complexes or aggregated gammaglobulin is highly improbable.

Blood ◽  
1986 ◽  
Vol 67 (3) ◽  
pp. 672-675 ◽  
Author(s):  
GA Adams ◽  
SD Swenson ◽  
G Rock

Abstract Human blood platelets were stored for five days as concentrates in 60 mL of: (a) plasma; (b) non-plasma medium with anticoagulant; and (c) non-plasma medium without anticoagulant. All preparations were equally functional when tested for platelet aggregation and release reaction in response to single agonist or synergistic pairs of agonists in vitro. Platelets stored in non-plasma medium with anti-coagulant had lower kallikrein, fibrino(gen)peptide A, lactate, and beta-thromboglobulin than did plasma controls after five days. In vivo recovery and survival of platelets stored in non-plasma medium with anticoagulant were 51.2% +/- 4.3% and 8.7 +/- 0.3 days, respectively, which were not statistically different from plasma controls of 39.2% +/- 4.9% and 7.2 +/- 0.8 days, respectively. It is concluded that platelets can be stored for five days in a non-plasma medium and still have good in vivo recoveries and survivals.


Blood ◽  
1975 ◽  
Vol 45 (3) ◽  
pp. 413-416
Author(s):  
H Holmsen ◽  
CA Setkowsky ◽  
HJ Day

[3H]-adenine-labeled human platelets in plasma were incubated with or without nonradioactive serotonin. Release reaction was then induced by ADP, epinephrine, collagen, or thrombin. Platelets that had been incubated with serotonin released four times as much serotonin as platelets incubated without serotonin. The specific radioactivities of the ATP and ADP released to plasma during release reaction induced with all four inducers were the same in both systems. This shows that when serotonin is taken up by human platelets, it enters the compartment containing nonmetabolic, granula-stored ATP, and not the compartment with metabolic extragranular ATP. These results suggest that the mechanism of serotonin storage in human platelets is similar to that in other species investigated, i.e., rabbit, guinea pig, and pig.


Blood ◽  
1976 ◽  
Vol 48 (2) ◽  
pp. 185-197
Author(s):  
JS Wiley ◽  
J Kuchibhotla ◽  
CC Shaller ◽  
RW Colman

Thrombin is known to reduce the K+ content of human platelets, but the subcellular origin of the lost K+ is not known. The effect of aggregating agents on K+ release was studied in platelets labeled in plasma by preincubation with 42KCI. Platelets were separated from plasma by gel filtration through Sepharose 2B equilibrated with K+ - free Tyrode's buffer. Platelet K+ was 116nEq/10(8) platelets, of which 23% was found to be extracellular immediately after gel filtration. K+ influx was 65 nEq/10(8) platelets/hr at pH 7.5 and was more rapid at pH 7.9. About 70% of cell K+ exchanged with plasma in 4 hr with first- order kinetics, while a minor fraction of about 30% exchanged with a slower time course. This slowly exchanging fraction of platelet K+ was thought to arise from heterogeneity in the platelet population. Epinephrine and ADP aggregated gel-filtered platelets and released serotonin, but with loss of only 5%-10% of cell K+ and no beta- glucuronidase. In contrast, thrombin released up to 30% of platelet K+, whether aggregation occurred or was prevented by not stirring the cells. The specific activity of K+ released by all aggregating agents was identical to the specific activity of total platelet K+. Thrombin (0.01–0.2 NIH U/ml) released serotonin and also beta-glucuronidase (an enzyme of the alpha-granule), and there was a linear relation between release of K+ and this enzyme (r = 0.88). No lysis of platelets occurred, since lactic dehydrogenase was not detected. Pretreatment of platelets with aspirin in vitro inhibited thrombin-induced release of serotonin but had no effect on the loss of K+ or beta-glucuronidase. In contrast, the ingestion of aspirin by mouth inhibited the release of serotonin, beta-glucuronidase, and K+ by thrombin. The data suggested that the K+ loss induced by thrombin was primarily derived from release of alpha-granules and that these organelles contained about 20% of the total platelet K+ in a freely exchangeable and nonsequestered state.


1985 ◽  
Vol 54 (02) ◽  
pp. 397-401 ◽  
Author(s):  
Johannes Nimpf ◽  
Helmut Wurm ◽  
Gerhard M Kostner

SummaryThe interaction of β2-glycoprotein-I (β2-G-I), a plasma constituent of unknown function, with blood platelets was studied. The following results were obtained: 1) β2-G-I binds to washed human platelets isolated by centrifugation (WP) at one kind of specific, saturable binding sites. The dissociation constant was found to be approx. 1 × 10−6M.2) In the presence of physiological concentrations of Ca++ (2.5 mM), this specific binding is markedly reduced. Unspecific binding of β2-G-I to platelets, however, is not influenced by Ca++.3) Platelets prepared by gel filtration (GFP), differing in their in vitro aggregability from WP, exhibit no specific binding of β2-G-I. Binding to GFP is also not induced by activation with thrombin, collagen or ADP.4) β2-G-I causes significant alteration of the ADP-induced aggregation of GFP. Aggregation induced by thrombin, collagen, arachidonic acid or PAF-acether, however is not altered by β2G-I.It is suggested, that pelleting during centrifugation causes irreversible rearrangements in the membrane of platelets.


Blood ◽  
1976 ◽  
Vol 48 (2) ◽  
pp. 185-197 ◽  
Author(s):  
JS Wiley ◽  
J Kuchibhotla ◽  
CC Shaller ◽  
RW Colman

Abstract Thrombin is known to reduce the K+ content of human platelets, but the subcellular origin of the lost K+ is not known. The effect of aggregating agents on K+ release was studied in platelets labeled in plasma by preincubation with 42KCI. Platelets were separated from plasma by gel filtration through Sepharose 2B equilibrated with K+ - free Tyrode's buffer. Platelet K+ was 116nEq/10(8) platelets, of which 23% was found to be extracellular immediately after gel filtration. K+ influx was 65 nEq/10(8) platelets/hr at pH 7.5 and was more rapid at pH 7.9. About 70% of cell K+ exchanged with plasma in 4 hr with first- order kinetics, while a minor fraction of about 30% exchanged with a slower time course. This slowly exchanging fraction of platelet K+ was thought to arise from heterogeneity in the platelet population. Epinephrine and ADP aggregated gel-filtered platelets and released serotonin, but with loss of only 5%-10% of cell K+ and no beta- glucuronidase. In contrast, thrombin released up to 30% of platelet K+, whether aggregation occurred or was prevented by not stirring the cells. The specific activity of K+ released by all aggregating agents was identical to the specific activity of total platelet K+. Thrombin (0.01–0.2 NIH U/ml) released serotonin and also beta-glucuronidase (an enzyme of the alpha-granule), and there was a linear relation between release of K+ and this enzyme (r = 0.88). No lysis of platelets occurred, since lactic dehydrogenase was not detected. Pretreatment of platelets with aspirin in vitro inhibited thrombin-induced release of serotonin but had no effect on the loss of K+ or beta-glucuronidase. In contrast, the ingestion of aspirin by mouth inhibited the release of serotonin, beta-glucuronidase, and K+ by thrombin. The data suggested that the K+ loss induced by thrombin was primarily derived from release of alpha-granules and that these organelles contained about 20% of the total platelet K+ in a freely exchangeable and nonsequestered state.


Blood ◽  
1986 ◽  
Vol 67 (3) ◽  
pp. 672-675 ◽  
Author(s):  
GA Adams ◽  
SD Swenson ◽  
G Rock

Human blood platelets were stored for five days as concentrates in 60 mL of: (a) plasma; (b) non-plasma medium with anticoagulant; and (c) non-plasma medium without anticoagulant. All preparations were equally functional when tested for platelet aggregation and release reaction in response to single agonist or synergistic pairs of agonists in vitro. Platelets stored in non-plasma medium with anti-coagulant had lower kallikrein, fibrino(gen)peptide A, lactate, and beta-thromboglobulin than did plasma controls after five days. In vivo recovery and survival of platelets stored in non-plasma medium with anticoagulant were 51.2% +/- 4.3% and 8.7 +/- 0.3 days, respectively, which were not statistically different from plasma controls of 39.2% +/- 4.9% and 7.2 +/- 0.8 days, respectively. It is concluded that platelets can be stored for five days in a non-plasma medium and still have good in vivo recoveries and survivals.


Blood ◽  
1975 ◽  
Vol 45 (3) ◽  
pp. 413-416 ◽  
Author(s):  
H Holmsen ◽  
CA Setkowsky ◽  
HJ Day

Abstract [3H]-adenine-labeled human platelets in plasma were incubated with or without nonradioactive serotonin. Release reaction was then induced by ADP, epinephrine, collagen, or thrombin. Platelets that had been incubated with serotonin released four times as much serotonin as platelets incubated without serotonin. The specific radioactivities of the ATP and ADP released to plasma during release reaction induced with all four inducers were the same in both systems. This shows that when serotonin is taken up by human platelets, it enters the compartment containing nonmetabolic, granula-stored ATP, and not the compartment with metabolic extragranular ATP. These results suggest that the mechanism of serotonin storage in human platelets is similar to that in other species investigated, i.e., rabbit, guinea pig, and pig.


1977 ◽  
Author(s):  
V.T. Turitto ◽  
H.J. Weiss ◽  
D.S. Cohen

An in Vitro perfusion technique introduced by Baumgartner has been used to investigate the interaction of human blood platelets with subendothelium of rabbit aortas. Platelet contact, adhesion (spreading) and the formation of ndcxothrombi were measured directly by use of a morphometric technique for a variety of exposure times (1 to 40 min) and a physiological range of flow rates (shear rates varying from 50 to 830 sec-1). A theory accounting for platelet transport through the blood and the platelet reactivity at the vessel surface Indicated platelet transport to be the controlling influence on platelet attachment. Under low shear conditions platelet attachment is unaltered by moderate changes in platelet reactivity. The results suggest that high shear rates (greater than 800 sec-1) are necessary for a sensitive measurement of defects in platelet attachment and that experimental devices which employ low shear conditions are limited in measuring such defects.


1968 ◽  
Vol 20 (03/04) ◽  
pp. 327-335 ◽  
Author(s):  
Ch Mueller-Eckhardt ◽  
E. F Lüscher

SummaryThe effects of the SH-inhibitors monoiodoacetate (MIA) and N-ethylmaleimide (NEM) on washed human blood platelets and on reactions of the platelets with immune complexes and antiplatelet antisera were studied. The following results were obtained:1. In the concentration range from 0.01 to 1 mM, only MIA in the highest concentration had a direct effect on platelets, discernible by a small but significant release of adenine nucleotides.2. The reaction of human platelets with heterologous anti-platelet antisera, heat aggregated human gammaglobulin, and gammaglobulin-coated latex particles was inhibited by MIA in concentrations of 0.1 mM and by NEM in concentrations of 1 mM, and higher.3. The SH-inhibitors tested exerted their influence on the platelet and not on the immune agents.4. L-cysteine was unable to reverse the effect of the SH-inhibitors on platelets. If added at room temperature in equimolar amounts to MIA and NEM 10 min prior to their contact with platelets, it abolished the effect of NEM, but not of MIA.5. The inhibition by MIA and NEM of platelet reactions with a variety of immune agents is comparable to the impairment of thrombin-induced viscous metamorphosis by SH-blockers. The obtained results do not support the assumption that immune agents and thrombin react with different, SH-group-containing substrates on the platelet surface.


1968 ◽  
Vol 20 (01/02) ◽  
pp. 168-179 ◽  
Author(s):  
Ch Mueller-Eckhardt ◽  
E. F Lüscher

Summary1. Provided they are coated with gammaglobulin, polystyrene latex particles induce in washed human blood platelets the release of adenine nucleotides, aggregation and the contraction of the formed aggregates. Albumin and fibrinogen are unable to replace gammaglobulin in this reaction. Particles with a diameter of about 0.8 μ proved most effective; larger ones were inactive.2. The release of nucleotides is a fast process; it is impaired but not completely inhibited by the removal of Ca++-ions. Aggregation and contraction of the aggregates are absent without Ca++-ions.3. Normal gammaglobulin by itself has scarcely an effect upon platelets and it fixes added hemolytic complement (C’) only to a negligible extent. After the adsorption to latex it acquires strong C’-fixing properties, and becomes more reactive towards platelets. Repeated adsorption of the same gammaglobulin preparation with latex did not change this behaviour, which therefore is due to a property of the gammaglobulin itself, and not of a preferentially adsorbed, C’-activating contaminant. Treatment at pH 4 of gammaglobulin before its adsorption onto latex simultaneously abolished its effects on platelets, and on C.4. It must be concluded that the effect of opsonized latex particles upon blood platelets is unseparable from their C’activating capacity. On the other hand, the addition of C’ not only proved unnecessary; the presence of serum rather impaired the release of nucleotides by latex particles.


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