scholarly journals Effect of anti-P1A1 antibody on human platelets. I. The role of complement

Blood ◽  
1979 ◽  
Vol 53 (4) ◽  
pp. 567-577 ◽  
Author(s):  
DB Cines ◽  
AD Schreiber
Keyword(s):  
Platelet Aggregation ◽  
Complement Activation ◽  
Platelet Rich Plasma ◽  
Plasma Concentrations ◽  
Human Platelets ◽  
Serotonin Release ◽  
Buffer System ◽  
Induce Platelet Aggregation ◽  
Platelet Surface ◽  
Release Reaction

Abstract We studied the interaction of complement with human platelets. Complement was activated by IgG anti-P1A1 antibody obtained from 3 patients with the post-transfusion purpura syndrome. We used a heparin- plasma buffer system that permits complement activation and also preserves platelet function. With this system complement activation was efficient, and platelet immune alteration was extensive. Anti-P1A1 antibody was effective only in the presence of complement, in which case both platelet lysis and serotonin release (release reaction) in the absence of lysis were observed. Platelet lysis, as assessed by 51Cr loss, required 10-fold more antibody than was necessary to induce platelet aggregation and release of 14C-serotonin. This platelet release reaction required an intact classic complement sequence through C6. The extent of platelet serotonin release parallelled the depletion of C1 and C4 from platelet-rich plasma. Concentrations of antibody insufficient to induce platelet aggregation and serotonin release could still activate C1 and deposit increased C3 on the platelet surface. These studies demonstrated that complement activation by anti-P1A1 antibody can alter human platelets in a nonlytic system. Several phases of complement-mediated human platelet alteration are possible, depending on the concentration of anti-P1A1 antibody.

scholarly journals Effect of anti-P1A1 antibody on human platelets. I. The role of complement

Blood ◽  
1979 ◽  
Vol 53 (4) ◽  
pp. 567-577
Author(s):  
DB Cines ◽  
AD Schreiber
Keyword(s):  
Platelet Aggregation ◽  
Complement Activation ◽  
Platelet Rich Plasma ◽  
Plasma Concentrations ◽  
Human Platelets ◽  
Serotonin Release ◽  
Buffer System ◽  
Induce Platelet Aggregation ◽  
Platelet Surface ◽  
Release Reaction

We studied the interaction of complement with human platelets. Complement was activated by IgG anti-P1A1 antibody obtained from 3 patients with the post-transfusion purpura syndrome. We used a heparin- plasma buffer system that permits complement activation and also preserves platelet function. With this system complement activation was efficient, and platelet immune alteration was extensive. Anti-P1A1 antibody was effective only in the presence of complement, in which case both platelet lysis and serotonin release (release reaction) in the absence of lysis were observed. Platelet lysis, as assessed by 51Cr loss, required 10-fold more antibody than was necessary to induce platelet aggregation and release of 14C-serotonin. This platelet release reaction required an intact classic complement sequence through C6. The extent of platelet serotonin release parallelled the depletion of C1 and C4 from platelet-rich plasma. Concentrations of antibody insufficient to induce platelet aggregation and serotonin release could still activate C1 and deposit increased C3 on the platelet surface. These studies demonstrated that complement activation by anti-P1A1 antibody can alter human platelets in a nonlytic system. Several phases of complement-mediated human platelet alteration are possible, depending on the concentration of anti-P1A1 antibody.

scholarly journals Activation of human platelets by immune complexes prepared with cationized human IgG

Blood ◽  
1993 ◽  
Vol 82 (10) ◽  
pp. 3045-3051
Author(s):  
M Schattner ◽  
M Lazzari ◽  
AS Trevani ◽  
E Malchiodi ◽  
AC Kempfer ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Platelet Activation ◽  
Immune Complexes ◽  
Platelet Rich Plasma ◽  
Human Platelets ◽  
Human Igg ◽  
Experimental Conditions ◽  
Induce Platelet Aggregation ◽  
Soluble Immune Complexes ◽  
High Concentrations

The present study shows that the ability of soluble immune complexes (IC), prepared with human IgG and rabbit IgG antibodies against human IgG, to trigger platelet activation was markedly higher for IC prepared with cationized human IgG (catIC) compared with those prepared with untreated human IgG (cIC). CatIC induced platelet aggregation and adenosine triphosphate release in washed platelets (WP), gel-filtered platelets (GFP), or platelet-rich plasma (PRP) at physiologic concentrations of platelets (3 x 10(8)/mL) and at low concentrations of catIC (1 to 30 micrograms/mL). On the contrary, under similar experimental conditions, cIC did not induce aggregation in PRP, WP, or GFP. Low aggregation responses were only observed using high concentrations of both WP (9 x 10(8)/mL) and cIC (500 micrograms/mL). Interestingly, catIC were also able to induce platelet activation under nonaggregating conditions, as evidenced by P-selectin expression. Cationized human IgG alone did not induce platelet aggregation in PRP but triggered either WP or GFP aggregation. However, the concentration needed to induce these responses, was about eightfold higher than those required for catIC. The responses induced either by catIC or cationized human IgG were completely inhibited by treatment with heparin, dextran sulphate, EDTA, prostaglandin E1, or IV3, a monoclonal antibody against the receptor II for the Fc portion of IgG (Fc gamma RII). The data presented in this study suggest that IgG charge constitutes a critical property that conditions the ability of IC to trigger platelet activation.

scholarly journals The effect of PGI2 and theophylline on the response of platelets subjected to shear stress

Blood ◽  
1981 ◽  
Vol 58 (4) ◽  
pp. 678-681 ◽  
Author(s):  
RA Hardwick ◽  
JD Hellums ◽  
DM Peterson ◽  
JL Moake ◽  
JD Olson
Keyword(s):  
Shear Stress ◽  
Platelet Aggregation ◽  
Platelet Rich Plasma ◽  
Antiplatelet Agent ◽  
Human Platelets ◽  
Clinical Applications ◽  
Serotonin Release ◽  
Large Reduction ◽  
Prior Work ◽  
Rotational Viscometer

A specially designed rotational viscometer was used to investigate the effects of the antiplatelet agent PGI2 in combination with theophylline on the response of human platelets subjected to shear stress. Samples of citrated platelet-rich plasma (PRP) were exposed to shear stress in the viscometer for a period of 5 min at 23 degrees C. The levels of stress studied ranged from 50 to 300 dynes/sq cm. Pretreatment of the platelets with 0.01 microM PGI2 and 500 microM theophylline before exposure to shear stress caused a large reduction in shear-induced platelet aggregation. However, it was also observed that the PGI2-- theophylline pretreatment concomitantly caused a large increase in shear-induced platelet lysis and serotonin release at stress levels equal to or greater than 150 dynes/sq cm. This observed increase in platelet fragility may have important implications for clinical applications of PGI2. The results are discussed and compared to those obtained in prior work in which platelets were pretreated with acetylsalicylic acid or with PGE1.

Effects of Lead Acetate on Platelet Aggregation, Ultrastructure and Serotonin Release

1971 ◽  
Vol 26 (03) ◽  
pp. 455-466 ◽  
Author(s):  
R. B Davis ◽  
G. C Holtz
Keyword(s):  
Platelet Aggregation ◽  
Platelet Function ◽  
Lead Acetate ◽  
Platelet Rich Plasma ◽  
Adenosine Diphosphate ◽  
Blood Platelet ◽  
Human Platelets ◽  
Serotonin Release ◽  
Aggregation Of Platelets

SummaryThe effects of lead on blood platelet function and ultrastructure have been investigated. Lead acetate was injected intravenously in 27 rats and was added to rat and human platelet rich plasma in vitro. In vitro studies showed that concentrations of 2.5 × 10-3 M lead acetate reduced or blocked aggregation of rat and human platelets by adenosine diphosphate, collagen, and thrombin. Radioactive serotonin release from human platelets was inhibited by 10-4 M lead acetate. One hour after the injection of lead, platelet aggregation by thrombin was reduced, but platelet aggregation by adenosine diphosphate and collagen showed little change. Three days after lead, aggregation of platelets by collagen and thrombin was blocked and aggregation by adenosine diphosphate reduced. Thrombocytopenia was present 4 days after intravenous lead acetate. Electron micrographs of platelets showed that the mean number of mitochondria per platelet was increased, whereas alpha granules were reduced. Dense bodies were not significantly changed. Lead acetate affects platelet function in concentrations reported in human bone marrow in lead poisoning, and may relate to the binding of free sulfhydryl groups by lead.

scholarly journals Platelet release reaction and intracellular cGMP

Blood ◽  
1978 ◽  
Vol 52 (3) ◽  
pp. 524-531 ◽  
Author(s):  
A Weiss ◽  
NL Baenziger ◽  
JP Atkinson
Keyword(s):  
Platelet Rich Plasma ◽  
Human Platelets ◽  
Serotonin Release ◽  
Secretory Process ◽  
Release Reaction ◽  
Intracellular Cgmp ◽  
Exogenous Addition ◽  
Human Thrombin ◽  
Platelet Release

Abstract Enchanced cAMP concentrations inhibit the aggregation and release reaction of isolated human platelets and platelet-rich plasma to all known inducing agents. An opposing role for cGMP in this phenomenon has been proposed by some but not by others, and the function of cGMP in this secretory process is unclear. To further elucidate the role of cGMP in the release reaction, the effect of increased concentrations of this cyclic nucleotide on 14C-serotonin release was evaluated utilizing isolated human platelets and highly purified human thrombin or commercially available bovine thrombin. Several recently described stimulators of guanylate cyclase, including sodium nitroprusside, sodium azide, nitrosoquanidines, and ascorbic acid, were found to markedly augment platelet cGMP levels. Enhanced platelet cGMP concentrations produced by these drugs or by the exogenous addition of cGMP and its analogues neither caused these cells to secrete nor modulated the thrombin-induced serotonin release reaction. The inhibition of serotonin release by increased cAMP concentrations was not counteracted by increased cGMP levels. Platelet cGMP concentrations were unaltered by thrombin. These data indicate that cGMP is not an obligatory signal or a modulator of the thrombin-induced platelet release reaction.

scholarly journals Activation of human platelets by immune complexes prepared with cationized human IgG

Blood ◽  
1993 ◽  
Vol 82 (10) ◽  
pp. 3045-3051 ◽  
Author(s):  
M Schattner ◽  
M Lazzari ◽  
AS Trevani ◽  
E Malchiodi ◽  
AC Kempfer ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Platelet Activation ◽  
Immune Complexes ◽  
Platelet Rich Plasma ◽  
Human Platelets ◽  
Human Igg ◽  
Experimental Conditions ◽  
Induce Platelet Aggregation ◽  
Soluble Immune Complexes ◽  
High Concentrations

Abstract The present study shows that the ability of soluble immune complexes (IC), prepared with human IgG and rabbit IgG antibodies against human IgG, to trigger platelet activation was markedly higher for IC prepared with cationized human IgG (catIC) compared with those prepared with untreated human IgG (cIC). CatIC induced platelet aggregation and adenosine triphosphate release in washed platelets (WP), gel-filtered platelets (GFP), or platelet-rich plasma (PRP) at physiologic concentrations of platelets (3 x 10(8)/mL) and at low concentrations of catIC (1 to 30 micrograms/mL). On the contrary, under similar experimental conditions, cIC did not induce aggregation in PRP, WP, or GFP. Low aggregation responses were only observed using high concentrations of both WP (9 x 10(8)/mL) and cIC (500 micrograms/mL). Interestingly, catIC were also able to induce platelet activation under nonaggregating conditions, as evidenced by P-selectin expression. Cationized human IgG alone did not induce platelet aggregation in PRP but triggered either WP or GFP aggregation. However, the concentration needed to induce these responses, was about eightfold higher than those required for catIC. The responses induced either by catIC or cationized human IgG were completely inhibited by treatment with heparin, dextran sulphate, EDTA, prostaglandin E1, or IV3, a monoclonal antibody against the receptor II for the Fc portion of IgG (Fc gamma RII). The data presented in this study suggest that IgG charge constitutes a critical property that conditions the ability of IC to trigger platelet activation.

Inhibition of Virus-Induced Platelet Aggregation by Treatment of Platelets with Neuraminidase

1975 ◽  
Author(s):  
M. A. Chernesky ◽  
R. P. B. Larke
Keyword(s):  
Sialic Acid ◽  
Platelet Aggregation ◽  
Sendai Virus ◽  
Adenine Nucleotides ◽  
Lactic Dehydrogenase ◽  
Human Platelets ◽  
Induce Platelet Aggregation ◽  
Platelet Surface ◽  
Thin Sections ◽  
Virus Attachment

Washed suspensions of rabbit or human platelets aggregate and release their constituents (adenine nucleotides, serotonin and lactic dehydrogenase) when mixed with Newcastle disease virus (NDV) or Sendai virus (paramyxoviruses) in a stirred system at 37° C. Treatment of rabbit platelets with chromatographically purified neuraminidase which removed 10–20 ug of sialic acid/101 platelets reduced, by more than 95%, platelet aggregation and release of constituents by virus; treated platelets were as responsive to stimulation with ADP or thrombin as were control platelets. Virus, which normally becomes associated with aggregated platelets, failed to attach to neuraminidase-treated platelets and was recovered in platelet supernatant fluids. Subsequent aggregation of these mixtures of virus and neuraminidase-treated platelets with thrombin failed to trap NDV in platelet aggregates. Electron microscopy (carbon replica and thin-sections) revealed an absence of virus attachment on surfaces of platelets treated with neuraminidase.These data indicate that a receptor substance containing sialic acid present on the platelet surface is necessary to enable paramyxoviruses to attach and induce platelet aggregation and release of platelet constituents.

scholarly journals Evaluation of Highly Purified Bovine F. VIII and Bovine Plasma as Reagents to Induce Platelet Aggregation

1977 ◽  
Author(s):  
M. A. Lazzari ◽  
C. Simonetti ◽  
G. Casillas ◽  
M. Pavlovsky
Keyword(s):  
Platelet Aggregation ◽  
Optical Density ◽  
Sodium Citrate ◽  
Platelet Rich Plasma ◽  
Human Platelets ◽  
Induce Platelet Aggregation ◽  
Bovine Plasma ◽  
Aggregation Factor ◽  
High Concentrations

Purified bovine F. VIII is a known reagent for human platelets aggregation used for the study of thrombopaties. As bovine plasma (BP)is easier to prepare and standardize it was studied as an alternative reagent, comparing it with purified bovine F. VIII. Platelet aggregation was studied by a turbidimetric technique(Aggregometer Bryston AG 1). The substrates were platelet rich plasma (PRP)and gel filtered platelets using between 150,000 and 200,000 platelets/mm3 to standardize the platelets surface. 1/10 dilution of bovine plasma was found to be the best for PRP and 1/1 for filtered platelets. Incubation of the substrates with bovine plasma at 37°C for 5 min seems to enhance PAF activity of the platelet aggregation factor (PAF). Primary aggregation was obtained in PRP treated with 2% tetrasodic EDTA, 3. 4% sodium citrate and in plasma with aspirin. No secondary aggregation was observed in EDTA or aspirin plasma. Unlike platelets treated with ADP, their shape did not change since the optical density was not modified. No synergism or competition between PAF and ADP or adrenalin were found. High concentrations of NaCl or urea interfere with PAF, and esposure to 56°C inactivates it. In 50 normal PRP the percentage of total aggregation were: BP 1/10 42% ± 12 ; BP 1/1 79% ± 13 ;purified bovine F. VIII 1/10 86% ± 6 and in 10 batches of filtered platelets bp 1/1 82% ± 7. We consider an advantage to use bovine plasma for platelets aggregation studies.

EFFECTS OF HUMAN ATRIAL NATRIURETIC PEPTIDES ON SECRETION REACTION IN HUMAN PLATELETS

1987 ◽  
Author(s):  
A Tanable ◽  
Y Yatomi ◽  
T Ohashi ◽  
H Oka ◽  
T Kariya ◽  
...  
Keyword(s):  
Platelet Rich Plasma ◽  
Atp Release ◽  
Smooth Muscle Contraction ◽  
Inhibitory Effect ◽  
Human Platelets ◽  
Serotonin Release ◽  
Release Reaction ◽  
Induced Aggregation ◽  
Atrial Natriuretic

Human atrial natriuretic peptide (h-ANP) has vasodilating and natriuretic properties, and inhibits smooth muscle contraction, renal renin secretion and adrenal aldosterone release. Although Schiffrin has reported that human platelets have receptors for ANP, its effects in platelets are not established in vivo. We therefore investigated the influence of h-ANP on secretion reaction in human platelets. Eight healthy subjects, males, aged 20 to 24 years, donated blood for the study. Citrated platelet-rich plasma (PRP) was incubated with or without h-ANP at 37 C for 2.5 minutes. The samples of 0.5 ml PRP then used to measure ADP induced aggregation, ATP release reaction and C-serotonin release reaction. H-ANP, at concentration of 1x10 -6M, decreased ADP induced aggregation (after h-ANP: 77.4±9.7 % of control aggregation), and inhibited ATP release reaction (after h-ANP: 31.8±13.1%). Serotonin releasereaction induced by ADP was also inhibited ( control: 15.3±2.2%, after h-ANP: 8.3±0.5 %). The inhibitory effect of h-ANP on aggregation and secretion reaction was maximal by 3 minutes. These data suggest that h-ANP inhibits secretion reaction in human platelets.

Thrombin Interaction with Human Platelets Potentiation of Thrombin-induced Aggregation and Release by Inactivated Thrombin

1974 ◽  
Vol 32 (01) ◽  
pp. 207-215 ◽  
Author(s):  
David R. Phillips
Keyword(s):  
Platelet Aggregation ◽  
Binding Sites ◽  
Human Platelet ◽  
Adenosine Diphosphate ◽  
Human Platelets ◽  
Induce Platelet Aggregation ◽  
Release Reaction ◽  
Proteolytic Site ◽  
Induced Aggregation ◽  
Inhibited Enzyme

SummaryThe possibility that thrombin acts on platelets by a mechanism other than proteolysis was investigated. The proteolytic site of thrombin was modified with phenylmethylsulfonyl fluoride (PMSF). This modified enzyme did not induce platelet aggregation or the platelet release reaction. Platelets were then incubated with the inactivated enzyme (PMS-thrombin) and later with active thrombin. In this sequence of incubation, PMS-thrombin enhanced not only platelet aggregation induced by active thrombin but also the thrombin-induced release reaction. Preincubation with PMS-thrombin was essential for this enhancement as the inhibited enzyme did not affect aggregation if added after active thrombin. The effect of PMS-thrombin was limited to thrombin-induced reactions of the platelet. The inhibited enzyme had no effect on aggregation induced by adenosine diphosphate or collagen, or on thrombininduced coagulation of fibrinogen. These results suggest (1) that both proteolytic and binding sites for thrombin are present on the human platelet plasma membrane ; and (2) that interaction of thrombin with the binding site potentiates the activity of the proteolytic site.

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