Influence of Platelet Membrane Sialic Acid and Platelet-Associated IgG on Ageing and Sequestration of Blood Platelets in Baboons

1993 ◽  
Vol 70 (04) ◽  
pp. 676-680 ◽  
Author(s):  
H F Kotzé ◽  
V van Wyk ◽  
P N Badenhorst ◽  
A du P Heyns ◽  
J P Roodt ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Life Span ◽  
Blood Platelets ◽  
Senescent Cell ◽  
Platelet Membrane ◽  
Antigen Complex ◽  
The Mean ◽  
Aggregation Of Platelets

SummaryPlatelets were isolated from blood of baboons and treated with neuraminidase to remove platelet membrane sialic acid, a process which artificially ages the platelets. The platelets were then labelled with 111In and their mean life span, in vivo distribution and sites of Sequestration were measured. The effect of removal of sialic acid on the attachment of immunoglobulin to platelets were investigated and related to the Sequestration of the platelets by the spleen, liver, and bone marrow. Removal of sialic acid by neuraminidase did not affect the aggregation of platelets by agonists in vitro, nor their sites of Sequestration. The removal of 0.51 (median, range 0.01 to 2.10) nmol sialic acid/108 platelets shortened their life span by 75 h (median, range 0 to 132) h (n = 19, p <0.001), and there was an exponential correlation between the shortening of the mean platelet life span and the amount of sialic acid removed. The increase in platelet-associated IgG was 0.112 (median, range 0.007 to 0.309) fg/platelet (n = 25, p <0.001) after 0.79 (median, range 0.00 to 6.70) nmol sialic acid/108 platelets was removed (p <0.001). There was an exponential correlation between the shortening of mean platelet life span after the removal of sialic acid and the increase in platelet-associated IgG. The results suggest that platelet membrane sialic acid influences ageing of circulating platelets, and that the loss of sialic acid may have exposed a senescent cell antigen that binds IgG on the platelet membrane. The antibody-antigen complex may then provide a signal to the macrophages that the platelet is old, and can be phagocytosed and destroyed.

scholarly journals Enhanced survival of sickle erythrocytes upon treatment with glyceraldehyde

Blood ◽  
1986 ◽  
Vol 67 (2) ◽  
pp. 544-546 ◽  
Author(s):  
LJ Benjamin ◽  
JM Manning
Keyword(s):  
Life Span ◽  
Lysine Residue ◽  
Red Cell ◽  
Hemoglobin Tetramer ◽  
Sickle Erythrocytes ◽  
The Mean

Abstract Glyceraldehyde has been demonstrated to be an antisickling agent in vitro. In the present investigation, chromium-51 red cell studies were used to investigate the life span in vivo of sickle erythrocytes after treatment with glyceraldehyde in vitro. The mean survival (T1/2) of control cells was 5.8 +/- 1.6 days, whereas cells treated with 10 mmol/L or 20 mmol/L glyceraldehyde survived 9.0 +/- 1.4 (P less than .05) and 11.3 +/- 0.8 (P less than .002) days, respectively. The extent of modification by glyceraldehyde was 0.4 to 1.0 lysine residue per hemoglobin tetramer. These studies demonstrate not only a prolongation of the life span of sickle erythrocytes by treatment with glyceraldehyde but also the absence of any deleterious effects that would be revealed by this study.

scholarly journals Comparison of thrombin and ristocetin in the interaction between von Willebrand factor and platelets

Blood ◽  
1983 ◽  
Vol 62 (2) ◽  
pp. 346-353 ◽  
Author(s):  
RL Harrison ◽  
PA McKee
Keyword(s):  
Platelet Aggregation ◽  
Platelet Membrane ◽  
Membrane Receptors ◽  
Low Concentrations ◽  
Platelet Membrane Receptor ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Aggregation Of Platelets

Abstract It is known that the antibiotic ristocetin exposes the platelet membrane receptor for factor VIII/von Willebrand glycoprotein (FVIII/vWF). Recent reports suggest that low concentrations of thrombin also cause platelet membrane receptors to become available for FVIII/vWF. As a consequence, the suspicion has been raised that thrombin provides similar or equivalent activity in vivo to that observed for ristocetin under in vitro conditions. In this study, we quantitated the extent to which thrombin promotes the binding of FVII/vWF to platelets and determined whether or not this interaction initiates or complements platelet aggregation. With ristocetin present, the amount of 125I-FVIII/vWF that became platelet-bound correlated closely with the onset, rate, and extent of platelet aggregation. In contrast, at every thrombin concentration tested, the amount of 125I- FVIII/vWF that specifically bound to platelets was about 6% of that observed with ristocetin. Significantly, FVIII/vWF did not augment the rate of aggregation of platelets in response to thrombin or initiate platelet aggregation when subaggregating doses of thrombin were used. These observations indicate that the minimal association that occurs between FVIII/vWF and the platelet membrane in the presence of thrombin does not correlate with platelet aggregation and therefore is not analogous to the effects of ristocetin. Whether the low level of binding relates to another process, such as platelet-endothelial interactions, remains unknown.

Labelling of Blood Platelets with Stable Tracers

1980 ◽  
Vol 44 (01) ◽  
pp. 030-031 ◽  
Author(s):  
D Del Principe ◽  
R Cesareo ◽  
B M Tallarida ◽  
M G Ciancarelli ◽  
M Ricci ◽  
...  
Keyword(s):  
Blood Platelets ◽  
Half Time ◽  
Simple Version ◽  
X Ray ◽  
Rabbit Platelets ◽  
Stable Tracers ◽  
The Mean

SummaryHalf-time values of platelets labelled with stable rubidium are compared to those of platelets labelled with Cr51. Platelets labelled with stable rubidium are assayed by a very simple version of the X-Ray fluorescence equipment. The mean quantity of rubidium incorporated by the cells is of about some µg Rb per ml blood.The in vitro half-time of human Rb labelled platelets stored at 22° C is 41.2 ± 3h compared with the value 44.8 ± 3h for platelets labelled with Cr51, as deduced by six experiments. The in vivo half-time of rabbit platelets labelled with stable rubidium is 22 ± 3h compared with the value 18 ± 3h of platelets labelled with Cr51; ten experiments were carried out.

scholarly journals Enhanced survival of sickle erythrocytes upon treatment with glyceraldehyde

Blood ◽  
1986 ◽  
Vol 67 (2) ◽  
pp. 544-546
Author(s):  
LJ Benjamin ◽  
JM Manning
Keyword(s):  
Life Span ◽  
Lysine Residue ◽  
Red Cell ◽  
Hemoglobin Tetramer ◽  
Sickle Erythrocytes ◽  
The Mean

Glyceraldehyde has been demonstrated to be an antisickling agent in vitro. In the present investigation, chromium-51 red cell studies were used to investigate the life span in vivo of sickle erythrocytes after treatment with glyceraldehyde in vitro. The mean survival (T1/2) of control cells was 5.8 +/- 1.6 days, whereas cells treated with 10 mmol/L or 20 mmol/L glyceraldehyde survived 9.0 +/- 1.4 (P less than .05) and 11.3 +/- 0.8 (P less than .002) days, respectively. The extent of modification by glyceraldehyde was 0.4 to 1.0 lysine residue per hemoglobin tetramer. These studies demonstrate not only a prolongation of the life span of sickle erythrocytes by treatment with glyceraldehyde but also the absence of any deleterious effects that would be revealed by this study.

scholarly journals Comparison of thrombin and ristocetin in the interaction between von Willebrand factor and platelets

Blood ◽  
1983 ◽  
Vol 62 (2) ◽  
pp. 346-353
Author(s):  
RL Harrison ◽  
PA McKee
Keyword(s):  
Platelet Aggregation ◽  
Platelet Membrane ◽  
Membrane Receptors ◽  
Low Concentrations ◽  
Platelet Membrane Receptor ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Aggregation Of Platelets

It is known that the antibiotic ristocetin exposes the platelet membrane receptor for factor VIII/von Willebrand glycoprotein (FVIII/vWF). Recent reports suggest that low concentrations of thrombin also cause platelet membrane receptors to become available for FVIII/vWF. As a consequence, the suspicion has been raised that thrombin provides similar or equivalent activity in vivo to that observed for ristocetin under in vitro conditions. In this study, we quantitated the extent to which thrombin promotes the binding of FVII/vWF to platelets and determined whether or not this interaction initiates or complements platelet aggregation. With ristocetin present, the amount of 125I-FVIII/vWF that became platelet-bound correlated closely with the onset, rate, and extent of platelet aggregation. In contrast, at every thrombin concentration tested, the amount of 125I- FVIII/vWF that specifically bound to platelets was about 6% of that observed with ristocetin. Significantly, FVIII/vWF did not augment the rate of aggregation of platelets in response to thrombin or initiate platelet aggregation when subaggregating doses of thrombin were used. These observations indicate that the minimal association that occurs between FVIII/vWF and the platelet membrane in the presence of thrombin does not correlate with platelet aggregation and therefore is not analogous to the effects of ristocetin. Whether the low level of binding relates to another process, such as platelet-endothelial interactions, remains unknown.

Characterization and Origin of Fibrinogen in Blood Platelets

1977 ◽  
Vol 38 (04) ◽  
pp. 0939-0954 ◽  
Author(s):  
Harold L. James ◽  
Pankaj Ganguly ◽  
Carl W. Jackson
Keyword(s):  
Human Platelet ◽  
Blood Platelets ◽  
Platelet Membrane ◽  
Plasma Fibrinogen ◽  
Time Intervals ◽  
Membrane Bound ◽  
Open Question ◽  
Physiologic Role

SummaryThe discovery of thrombin-clottable protein in platelet homogenates initiated studies on the location, properties, and origin of such material, the ultimate aim of which has been to define its physiologic role. It was established that fibrinogen is present both on the platelet membrane as well as in the cytoplasmic α-granules. The membrane-bound material is apparently fibrinogen adsorbed from plasma, while the intracellular fibrinogen appears to have unique biochemical and functional properties. Differences in properties observed between platelet fibrinogen and plasma fibrinogen are not due to in vitro modifications during handling. Whether the intracellular fibrinogen is synthesized in the platelet (or megakaryocyte) or whether it is derived through uptake and limited modification of plasma fibrinogen in vivo has remained an open question. Thus, to investigate the aspect of origin of platelet fibrinogen, radioactively-labelled fibrinogen was injected into rats, blood was collected at time intervals and the radioactivity in the subcellular fractions of platelets was examined. A part of the injected fibrinogen became associated with the platelets, but very little was found in the granule fraction. Previous findings on human platelet fibrinogen, together with the present data obtained using rats, suggest that platelet fibrinogen may not be derived from plasma fibrinogen in vivo. It thus is apparent that the intracellular fibrinogen is synthesized by a unique genetic mechanism. Molecular properties of fibrinogen derived from rat platelet granules were shown analogous to the properties of fibrinogen from human platelet granules. Fibrinogen of intracellular origin is less stable than its plasma counterpart. The results obtained by others in which identity of platelet and plasma fibrinogens was reported may be explained on the basis of recovery of only the fibrinogen component bound to the platelet membrane, which is adsorbed plasma fibrinogen. It is suggested that the term platelet fibrinogen may be used to denote that present in the α-granules, with the membrane-bound component being referred to as platelet-associated fibrinogen.

Storage of Human Blood Platelets

1974 ◽  
Vol 32 (02/03) ◽  
pp. 405-416 ◽  
Author(s):  
M. R Hardeman ◽  
Carina J L. Heynens
Keyword(s):  
Storage Temperature ◽  
Platelet Rich Plasma ◽  
Blood Platelets ◽  
Storage Period ◽  
Serotonin Uptake ◽  
Hypotonic Shock ◽  
Glycolytic Intermediates

SummaryStorage experiments were performed at 4°, 25° and 37° C with platelet-rich plasma under sterile conditions. In some experiments also the effect of storing platelets at 4° C in whole blood was investigated.Before, during and after three days of storage, the platelets were tested at 37° C for their serotonin uptake and response to hypotonic shock. In addition some glycolytic intermediates were determined.A fair correlation was noticed between the serotonin uptake and hypotonic shock experiments. Both parameters were best maintained at 25° C. Also platelet counting, performed after the storage period, indicated 25° C as the best storage temperature. Determination of glycolytic intermediates did not justify any conclusion regarding the optimal storage temperature. Of the various anticoagulants studied, ACD and heparin gave the best results as to the serotonin uptake and hypotonic shock response, either with fresh or stored platelets. The use of EDTA resulted in the lowest activity, especially after storage.The results of these storage experiments in vitro, correspond well with those in vivo reported in the literature.

Action of Lysolecithin on Blood Platelets

1963 ◽  
Vol 09 (03) ◽  
pp. 512-524 ◽  
Author(s):  
Chava Kirschmann ◽  
Sara Aloof ◽  
Andre de Vries
Keyword(s):  
Blood Platelets ◽  
Protective Action ◽  
Platelet Surface ◽  
Washed Platelet ◽  
Sufficient Concentration ◽  
Saline Medium

SummaryLysolecithin is adsorbed to washed blood platelets and, at sufficient concentration, lyses them, inhibits their clot-retracting activity and promotes their thromboplastin-generating activity. Lysolecithin adsorption to the platelet was studied by using P32-labelled lysolecithin obtained from the liver of rats injected with labelled orthophosphate. The amount of lysolecithin adsorbed to the surface of the washed platelet in saline medium is dependent on the concentration of lysolecithin in solution and reaches saturation — 5 × 10-8 jig per platelet — at a concentration of 9—10 µg per ml. Platelet lysis in saline medium begins at a lysolecithin concentration higher than 18 jig per ml. Plasma and albumin prevent adsorption of lysolecithin to the platelet and protect the platelet from damage by lysolecithin. Albumin is able to remove previously adsorbed lysolecithin from the platelet surface. The protective action of plasma explains the lack of platelet damage in blood, the plasma lecithin of which has been converted to lysolecithin by the action of Vipera palestinae venom phosphatidase, in vitro and in vivo.

scholarly journals Formulation and in vitro evaluation of self-nanoemulsifying liquisolid tablets of furosemide

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lena Dalal ◽  
Abdul Wahab Allaf ◽  
Hind El-Zein
Keyword(s):  
Theoretical Model ◽  
Castor Oil ◽  
In Vivo Studies ◽  
Coating Materials ◽  
Peg 400 ◽  
The Mean ◽  
Usp Apparatus ◽  
Solid System

AbstractSelf-nanoemulsifying drug delivery systems (SNEDDS) were used to enhance the dissolution rate of furosemide as a model for class IV drugs and the system was solidified into liquisolid tablets. SNEDDS of furosemide contained 10% Castor oil, 60% Cremophor EL, and 30% PEG 400. The mean droplets size was 17.9 ± 4.5 nm. The theoretical model was used to calculate the amounts of the carrier (Avicel PH101) and coating materials (Aerosil 200) to prepare liquisolid powder. Carrier/coating materials ratio of 5/1 was used and Ludipress was added to the solid system, thus tablets with hardness of 45 ± 2 N were obtained. Liquisolid tablets showed 2-folds increase in drug release as compared to the generic tablets after 60 min in HCl 0.1 N using USP apparatus-II. Furosemide loaded SNEDDS tablets have great prospects for further in vivo studies, and the theoretical model is useful for calculating the adequate amounts of adsorbents required to solidify these systems.

Elimination of three doses of gentamicin over three consecutive days using a polyacrylonitrile-derived filter: An in vitro assessment

2021 ◽  
pp. 039139882110322
Author(s):  
Frédéric J Baud ◽  
Vanessa Seif ◽  
Pascal Houzé ◽  
Jean-Herlé Raphalen ◽  
Benoît Pilmis ◽  
...  
Keyword(s):  
Life Span ◽  
Bolus Dose ◽  
Central Compartment ◽  
Daily Session ◽  
Progressive Decrease ◽  
Time Dependency ◽  
Study Results ◽  
In Vitro Assessment ◽  
The Mean

Introduction: Adsorption of gentamicin in a polyacrylonitrile filter was previously evidenced in a session lasting 6 h using the NeckEpur model. We extended the study over three consecutive days to mimic the 72-h life span of a filter. Methods: Prismaflex® monitor and ST150® filter were used in the continuous diafiltration (CDF) mode at a 2.5 L/h flowrate. The daily session started with a 6-h session of CDF. Thereafter, the 5-L central compartment was changed using a bag free of gentamicin to assess gentamicin release over the following 18 h. Experiments were repeated on Day 2 and stopped at the end of the 6-h session of CDF on Day 3. The experiment was performed in duplicate. Results: At a 2.5 L/h diafiltration flowrate, the mean daily clearances of gentamicin were 5.5, 4.0, and 3.3 L/h, respectively. The mean diafiltration and adsorption ratios in the daily elimination of gentamicin were 32/68%, 58/42%, and 88/12%, respectively. During days 1 and 2, the mean amount of gentamicin released from the ST150® filter were 14 and 34 mg, respectively. Conclusion: The pharmacokinetics of gentamicin over 3 days is strongly altered by adsorption in the same filter with a progressive decrease of elimination by adsorption, suggesting saturation of the filter. One limitation of our study results from the mode of administration using a bolus dose instead of an infusion over 30 min. Adsorption adds a clearance to those of diafiltration. The time-dependency of gentamicin clearance precludes using a constant dosage regimen over the filter’s life span.

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