Studies on the Platelet Defect in Alcoholism

SummaryPlatelet ultrastructure, protein composition, and adenine nucleotide metabolism were studied in patients ingesting ethanol to elucidate the mechanism of ethanol-induced changes in platelet function and survival. Serial measurements were made in 2 patients who maintained blood ethanol levels in excess of 300 mg/100 ml for 3 to 4 weeks. No major changes in structure or metabolism were detected in platelets from the patient whose platelet counts remained stable during the ingestion period. By contrast, the development of thrombocytopenia in the other patient was associated with significantly reduced intracellular ADP, increased ATP/ADP ratio, decreased release of ADP, increased specific radioactivity of intracellular ATP and ADP, and increased formation of hypoxanthine. Additionally, platelets from this patient varied markedly in size, contained giant granules, and possessed a poorly defined micro-tubular system. After stimulation with ADP or collagen, centripetal granule migration was retarded, and the aggregates formed were small and loose. Several large proteins were absent from the supernatant fraction of sonicated platelets from the thrombocytopenic patient. Exposure of normal platelets to ethanol in vitro resulted in no detectable change in platelet ultrastructure. The data indicate that the ethanol-related abnormalities of platelet function are due in part to subnormal amounts of intracellular ADP and a deficit in the storage pool of ADP. Additionally, the results suggest that impairment in the release mechanism to the observed defect in the release reaction.

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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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Endogenous adenosine produced during hypoxia attenuates neutrophil accumulation: coordination by extracellular nucleotide metabolism

Blood ◽

10.1182/blood-2004-06-2066 ◽

2004 ◽

Vol 104 (13) ◽

pp. 3986-3992 ◽

Cited By ~ 245

Author(s):

Holger K. Eltzschig ◽

Linda F. Thompson ◽

Jorn Karhausen ◽

Richard J. Cotta ◽

Juan C. Ibla ◽

...

Keyword(s):

Adenine Nucleotide ◽

Adenosine Monophosphate ◽

Nucleotide Metabolism ◽

Neutrophil Accumulation ◽

Endogenous Adenosine ◽

Critical Control Points ◽

Adenine Nucleotide Metabolism ◽

Anti Inflammatory

Abstract Hypoxia is a well-documented inflammatory stimulus and results in tissue polymorphonuclear leukocyte (PMN) accumulation. Likewise, increased tissue adenosine levels are commonly associated with hypoxia, and given the anti-inflammatory properties of adenosine, we hypothesized that adenosine production via adenine nucleotide metabolism at the vascular surface triggers an endogenous anti-inflammatory response during hypoxia. Initial in vitro studies indicated that endogenously generated adenosine, through activation of PMN adenosine A2A and A2B receptors, functions as an antiadhesive signal for PMN binding to microvascular endothelia. Intravascular nucleotides released by inflammatory cells undergo phosphohydrolysis via hypoxia-induced CD39 ectoapyrase (CD39 converts adenosine triphosphate/adenosine diphosphate [ATP/ADP] to adenosine monophosphate [AMP]) and CD73 ecto-5′-nucleotidase (CD73 converts AMP to adenosine). Extensions of our in vitro findings using cd39- and cd73-null animals revealed that extracellular adenosine produced through adenine nucleotide metabolism during hypoxia is a potent anti-inflammatory signal for PMNs in vivo. These findings identify CD39 and CD73 as critical control points for endogenous adenosine generation and implicate this pathway as an innate mechanism to attenuate excessive tissue PMN accumulation. (Blood. 2004;104:3986-3992)

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Phospholipid and adenine nucleotide metabolism in muscle after burn injury

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1985.249.5.r603 ◽

1985 ◽

Vol 249 (5) ◽

pp. R603-R610

Author(s):

J. Turinsky ◽

I. H. Chaudry

Keyword(s):

Burn Injury ◽

Adenine Nucleotide ◽

Adenine Nucleotides ◽

Energy Charge ◽

Nucleotide Metabolism ◽

Adenylate Energy Charge ◽

Adenine Nucleotide Metabolism ◽

Limb Muscles ◽

32P Incorporation

The role of phospholipid and adenine nucleotide metabolism in postburn unresponsiveness of muscle to insulin was examined. A single hindlimb scald in the rat was produced, and 3 days later soleus muscles were incubated in vitro with and without insulin. Under basal conditions muscles from the burned limbs had normal contents of phosphatidylcholine and phosphatidylinositol but decreased diphosphatidylglycerol (-39%) and phosphatidylethanolamine (-24%) and increased sphingomyelin (+62%), lysophosphatidylcholine (+68%), and phosphatidylserine (+13%) compared with the contralateral unburned limb. Such muscle also incorporated 107-396% more [32P]phosphate into all measured phospholipids, except for diphosphatidylglycerol. The presence of insulin had no effect on either the mass of phospholipids or 32P incorporation in any muscle. The burned limb muscles (frozen in situ) also exhibited lower levels of ATP (-25%) and total adenine nucleotides (-24%) than uninjured muscle but normal adenylate energy charge. The burned limb muscles had lower adenosine (-37%), but inosine and hypoxanthine were 82 and 39% higher, respectively. These data suggest recovery of muscle from local thermal injury is associated with alterations in mass, and possibly also turnover, of tissue phospholipids, the measured phospholipids do not mediate the postreceptor action of insulin in normal muscle, energy charge of the recovering injured muscle is restored before ATP level at the time when this muscle is unresponsive to insulin stimulation.

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Hydrogen peroxide, an inhibitor of platelet function: Effect on adenine nucleotide metabolism, and the release reaction

American Journal of Hematology ◽

10.1002/ajh.2830020108 ◽

1977 ◽

Vol 2 (1) ◽

pp. 53-63 ◽

Cited By ~ 34

Author(s):

Marie J. Stuart ◽

Holm Holmsen

Keyword(s):

Hydrogen Peroxide ◽

Platelet Function ◽

Adenine Nucleotide ◽

Nucleotide Metabolism ◽

Release Reaction ◽

Adenine Nucleotide Metabolism

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Adenine Nucleotide Metabolism of Human Platelets

Thrombosis and Haemostasis ◽

10.1055/s-0038-1654297 ◽

1971 ◽

Vol 25 (02) ◽

pp. 223-233

Author(s):

M Murakami ◽

K Odake

Keyword(s):

Adenine Nucleotide ◽

Platelet Rich Plasma ◽

Adenine Nucleotides ◽

Human Platelets ◽

Nucleotide Metabolism ◽

The Other ◽

Supernatant Fraction ◽

Two Dimensional ◽

Adenine Nucleotide Metabolism ◽

Layer Chromatography

SummaryAfter platelet-rich plasma was incubated with radioactive adenine, radioactive adenine nucleotides in platelets were separated by two-dimensional thin-layer chromatography.Radioactive adenine was selectively incorporated into adenine nucleotides. Gradual decomposition of labelled nucleotides was observed after longer period of incubation. Radioactive ATP, ADP, AMP, IMP, and hypoxanthine were separated from PCA extract of platelets. On the other hand, radioactive adenine and hypoxanthine were separated from platelet-poor plasma.After thrombin treatment, radioactive ATP in platelets broke down rapidly, while radioactive ADP decreased more slowly. Radioactive AMP increased at first in the cellular and supernatant fractions, and then decreased gradually. The accumulation of radioactive hypoxanthine was observed in the supernatant fraction. Released radioactive ATP and ADP were 23% and 22% of the initial radioactive ATP and ADP in platelets, respectively.

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Adenine nucleotide metabolism by chondrocytes in vitro: Role of ATP in chondrocyte maturation and matrix mineralization

Journal of Cellular Physiology ◽

10.1002/jcp.1041650304 ◽

1995 ◽

Vol 165 (3) ◽

pp. 468-474 ◽

Cited By ~ 39

Author(s):

Masashi Hatori ◽

Cristina C. Teixeira ◽

Kristine Debolt ◽

Maurizio Pacifici ◽

Irving M. Shapiro

Keyword(s):

Adenine Nucleotide ◽

Nucleotide Metabolism ◽

Matrix Mineralization ◽

Chondrocyte Maturation ◽

Adenine Nucleotide Metabolism

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L-Arginine Intake Effect on Adenine Nucleotide Metabolism in Rat Parenchymal and Reproductive Tissues

The Scientific World JOURNAL ◽

10.1100/2012/208239 ◽

2012 ◽

Vol 2012 ◽

pp. 1-4 ◽

Cited By ~ 5

Author(s):

G. Kocic ◽

J. Nikolic ◽

T. Jevtovic-Stoimenov ◽

D. Sokolovic ◽

H. Kocic ◽

...

Keyword(s):

Adenosine Deaminase ◽

Adenine Nucleotide ◽

Adenine Nucleotides ◽

Tissue Growth ◽

Nucleotide Metabolism ◽

Amp Deaminase ◽

Male Impotence ◽

Adenine Nucleotide Metabolism ◽

Adenosine Concentration ◽

Male Wistar Rats

L-arginine is conditionally essetcial amino acid, required for normal cell growth, protein synthesis, ammonia detoxification, tissue growth and general performance, proposed in the treatment of men sterility and prevention of male impotence. The aim of the present paper was to estimate the activity of the enzymes of adenine nucleotide metabolism:5′-nucleotidase (5′-NU), adenosine deaminase (ADA), AMP deaminase, and xanthine oxidase (XO), during dietary intake of L-arginine for a period of four weeks of male Wistar rats. Adenosine concentration in tissues is maintained by the relative activities of the adenosine-producing enzyme,5′-NU and the adenosine-degrading enzyme-ADA adenosine deaminase. Dietary L-arginine intake directed adenine nucleotide metabolism in liver, kidney, and testis tissue toward the activation of adenosine production, by increased5′-NU activity and decreased ADA activity. Stimulation of adenosine accumulation could be of importance in mediating arginine antiatherosclerotic, vasoactive, immunomodulatory, and antioxidant effects. Assuming that the XO activity reflects the rate of purine catabolism in the cell, while the activity of AMP deaminase is of importance in ATP regeneration, reduced activity of XO, together with the increased AMP-deaminase activity, may suggest that adenine nucleotides are presumably directed to the ATP regenerating process during dietary L-arginine intake.

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Release-induced changes in adenine nucleotide metabolism of human blood platelets

Thrombosis Research ◽

10.1016/0049-3848(79)90139-7 ◽

1979 ◽

Vol 15 (3-4) ◽

pp. 309-318 ◽

Cited By ~ 2

Author(s):

I. von Pusch ◽

W. Wesemann

Keyword(s):

Human Blood ◽

Adenine Nucleotide ◽

Blood Platelets ◽

Nucleotide Metabolism ◽

Adenine Nucleotide Metabolism ◽

Induced Changes ◽

Human Blood Platelets

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The Murine Misty Mutation: Phenotypic Effects on Melanocytes, Platelets and Brown Fat

Genetics ◽

10.1093/genetics/148.1.381 ◽

1998 ◽

Vol 148 (1) ◽

pp. 381-390

Author(s):

Elena V Sviderskaya ◽

Edward K Novak ◽

Richard T Swank ◽

Dorothy C Bennett

Keyword(s):

Coat Color ◽

Adenine Nucleotide ◽

Primary Cultures ◽

Cell Types ◽

Nucleotide Metabolism ◽

Brown Fat ◽

Melanocyte Stimulating Hormone ◽

Prolonged Bleeding Time ◽

Adenine Nucleotide Metabolism

Abstract Although the recessive murine mutation misty (m) is well known, its phenotype has never been reported beyond brief descriptions of a dilution of coat color and white spotting of the belly and extremities, suggesting a developmental mutation. A report in abstract has also suggested effects on white fat and body weight. Here, we report effects of the homozygous misty mutation on an unusual combination of three cell types: melanocytes, platelets, and brown fat. Brown fat appeared to be completely absent from all expected locations in neonatal m/m mice. A prolonged bleeding time was observed; platelet count and platelet serotonin and ATP levels were normal, but the level of ADP in m/m platelets was low. Primary cultures and immortal lines of melanocytes from m/m mice showed several abnormalities. There was a marked deficiency in net proliferation, suggesting that the color dilution and spotting in vivo may result from reduced numbers of melanocytes and their precursors. m/m melanocytes were also hyperdendritic in morphology, overproduced melanin, and had deficient responses to the cAMP agonists cholera toxin and melanocyte-stimulating hormone, which normally promote melanin production. The misty gene product may be involved in adenine nucleotide metabolism or signaling.

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