Adenine Nucleotides of Ischemic Intestine Do Not Reflect Injury

SummaryThe minimal concentration of the platelet aggregation principle (Platelet Aggregoserpen- tin, PAS) necessary to induce platelet aggregation was 10 ng/ml, about one-hundredth of that of the crude venom. PAS induced the release of platelet factors 3 and 4 from platelets, but the released platelet factor 3 was easily inactivated by the anti-phospholipid effect of PAS. Pretreatment of platelets with neuraminidase potentiated PAS-induced platelet aggregation. PAS-induced platelet aggregation was independent on released ADP; it could occur in the ADP-removing systems, such as apyrase or a combination of phosphoenolpyruvate and pyruvate kinase. However, PAS-induced platelet aggregation could be inhibited by adenine nucleotides and adenosine.PAS-induced platelet aggregation was inhibited by some anti-inflammatory agents, antimalarial drugs, local anesthetics, antihistamine and smooth muscle relaxants. After deaggregation of PAS-treated platelets, thrombin and sodium arachidonate could further induce platelet aggregation, but ADP and second dose of PAS could not. It is concluded that PAS-induced platelet aggregation is due to prostaglandin synthesis. Recent literatures on the mechanism of platelet aggregation were surveyed and the actions of PAS were discussed.

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The Platelet of the Newborn Infant – Adenine Nucleotide Metabolism and Release

Thrombosis and Haemostasis ◽

10.1055/s-0038-1650026 ◽

1980 ◽

Vol 43 (02) ◽

pp. 099-103 ◽

Cited By ~ 9

Author(s):

J M Whaun ◽

P Lievaart ◽

Keyword(s):

Newborn Infant ◽

Adenine Nucleotide ◽

Platelet Rich Plasma ◽

Adenine Nucleotides ◽

Newborn Infants ◽

Specific Radioactivity ◽

Nucleotide Metabolism ◽

Breakdown Product ◽

Term Infants ◽

Adenine Nucleotide Metabolism

SummaryBlood from normal full term infants, mothers and normal adults was collected in citrate. Citrated platelet-rich plasma was prelabelled with 3H-adenine and reacted with release inducers, collagen and adrenaline. Adenine nucleotide metabolism, total adenine nucleotide levels and changes in sizes of these pools were determined in platelets from these three groups of subjects.At rest, the platelet of the newborn infant, compared to that of the mother and normal adult, possessed similar amounts of adenosine triphosphate (ATP), 4.6 ± 0.2 (SD), 5.0 ± 1.1, 4.9 ± 0.6 µmoles ATP/1011 platelets respectively, and adenosine diphosphate (ADP), 2.4 ± 0.7, 2.8 ± 0.6, 3.0 ± 0.3 umoles ADP/1011 platelets respectively. However the marked elevation of specific radioactivity of ADP and ATP in these resting platelets indicated the platelet of the neonate has decreased adenine nucleotide stores.In addition to these decreased stores of adenine nucleotides, infant platelets showed significantly impaired release of ADP and ATP on exposure to collagen. The release of ADP in infants, mothers, and other adults was 0.9 ± 0.5 (SD), 1.5 ± 0.5, 1.5 ± 0.1 umoles/1011 platelets respectively; that of ATP was 0.6 ± 0.3, 1.0 ± 0.1,1.3 ± 0.2 µmoles/1011 platelets respectively. With collagen-induced release, platelets of newborn infants compared to those of other subjects showed only slight increased specific radioactivities of adenine nucleotides over basal levels. The content of metabolic hypoxanthine, a breakdown product of adenine nucleotides, increased in both platelets and plasma in all subjects studied.In contrast, with adrenaline as release inducer, the platelets of the newborn infant showed no adenine nucleotide release, no change in total ATP and level of radioactive hypoxanthine, and minimal change in total ADP. The reason for this decreased adrenaline reactivity of infant platelets compared to reactivity of adult platelets is unknown.Infant platelets may have different membranes, with resulting differences in regulation of cellular processes, or alternatively, may be refractory to catecholamines because of elevated levels of circulating catecholamines in the newborn period.

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Newborn Platelet Dysfunction: a Storage Pool and Release Defect

Thrombosis and Haemostasis ◽

10.1055/s-0038-1648025 ◽

1976 ◽

Vol 36 (01) ◽

pp. 200-207 ◽

Cited By ~ 30

Author(s):

Donald G. Corby ◽

Thomas F. Zuck

Keyword(s):

Specific Activity ◽

Platelet Rich Plasma ◽

Adenine Nucleotides ◽

Blood Platelets ◽

Newborn Infants ◽

Specific Radioactivity ◽

High Dose ◽

Platelet Dysfunction ◽

Paired Samples ◽

Normal Adults

SummaryPer cent aggregation, release and content of adenine nucleotides, and specific radioactivity were evaluated in citrated platelet-rich plasma (PRP) prepared from paired samples of maternal and cord blood. Platelets of newborn infants aggregated normally in response to high dose ADP (20 μM), strong collagen suspensions, and thrombin; however, when compared with PRP from the mothers or from normal adults, per cent aggregation in response to lower concentrations of ADP (2 μM), weak collagen, and part particularly epinephrine was markedly reduced. Nucleotide release after stimulation of the newborns’ PRP with the latter two inducers was also impaired. ATP and ADP content of the newborns’ platelets was also significantly less than that of their mothers or of normal adults, but specific activity was normal. The data suggest that the impairment of ADP release in the platelets of newborn infants is due to decreased sensitivity to external stimuli. Since metabolic ATP is necessary for the platelet release reaction, it is postulated that the platelet dysfunction results from a lack of metabolic ATP.

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Determination and Concentration of Adenine Nucleotides in Human Blood

Scandinavian Journal of Clinical and Laboratory Investigation ◽

10.3109/00365516009046161 ◽

1960 ◽

Vol 12 (1) ◽

pp. 10-17 ◽

Cited By ~ 13

Author(s):

K. Overgård-Hansen ◽

S. Jørgexsen

Keyword(s):

Human Blood ◽

Adenine Nucleotides

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Polymeric Liquid Membrane Electrodes Incorporated with Macrocyclic Hexaamines for Screening Adenine Nucleotides

Combinatorial Chemistry & High Throughput Screening ◽

10.2174/1386207003331436 ◽

2000 ◽

Vol 3 (6) ◽

pp. 509-517 ◽

Cited By ~ 6

Author(s):

Iwona Szymanska ◽

Hanna Radecka ◽

Jerzy Radecki ◽

Marek Pietraszkiewicz ◽

Oksana Pietraszkiewicz

Keyword(s):

Liquid Membrane ◽

Adenine Nucleotides ◽

Membrane Electrodes ◽

Polymeric Liquid

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Loss of 111Indium as indicator of platelet injury

Blood ◽

10.1182/blood.v58.2.350.350 ◽

1981 ◽

Vol 58 (2) ◽

pp. 350-353 ◽

Cited By ~ 18

Author(s):

JH Joist ◽

RK Baker

Keyword(s):

Small Molecules ◽

Adenine Nucleotides ◽

Human Platelets ◽

Metabolic Energy ◽

Platelet Factor ◽

Platelet Protein ◽

Threshold Rate ◽

Immune Injury ◽

Triton X

Abstract We previously demonstrated that platelets can be labeled with 111Inoxine with high labeling efficiency and that 111In is not liberated from labeled platelets during the platelet release reaction or prolonged in vitro storage. In view of these findings, we examined the potential usefulness of loss of 111In from labeled platelets as an indicator or platelet damage by comparing the loss of 111In with that of 51Cr and LDH (in some experiments also with platelet factor 3 availability) under different conditions of platelet injury. When washed human platelets labeled with either 51Cr-chromate or 111In-oxine were exposed to increasing concentrations of detergents (Triton X-100, lysolecithin), threshold, rate, and extent of loss of 111In, 51Cr and, LDH were similar. In contrast, when labeled platelets were depleted of metabolic energy by incubation in glucose-free Tyrode albumin solution or glucose-depleted plasma in the presence of antimycin A and 2-deoxy-D- glucose, loss of 51Cr (and PF3a) occurred earlier and progressed at a faster rate than that of 111In or LDH. Similar results were obtained when platelets were exposed to increasing concentrations of PlA1 antibody, causing complement-mediated immune injury. The findings indicate that with certain agents that cause rapid platelet disruption (lysis), different platelet constituents are lost at similar rates. However, under conditions of more subtle or slowly progressive platelet injury, small molecules such as adenine nucleotides (51Cr) may escape earlier and at faster rates than larger molecules such as LDH or 111In- binding platelet protein. Thus, neither 111In loss nor LDH loss appear to be suitable indicators for sublytic or prelytic platelet injury.

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