Phospholipid and adenine nucleotide metabolism in muscle after burn injury

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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Labeling of the releasable adenine nucleotides of washed human platelets

Blood ◽

10.1182/blood.v49.1.89.89 ◽

1977 ◽

Vol 49 (1) ◽

pp. 89-99 ◽

Cited By ~ 25

Author(s):

HJ Reimers ◽

MA Packham ◽

JF Mustard

Keyword(s):

Adenine Nucleotide ◽

Adenine Nucleotides ◽

Energy Charge ◽

Human Platelets ◽

Transport Processes ◽

Adenylate Energy Charge ◽

Prolonged Incubation ◽

Atp Pool ◽

Adenine Nucleotide Pool

Abstract In rabbit platelets, the metabolically active ATP pool equilibrates with the releasable ATP pool within 1 day. The studies showing this have now been extended to human platelets. Human platelets labeled with 14C-adenosine or 14C-adenine were incubated for up to 10 hr in vitro at 37 degrees C. After 10 hr, about 12% of the total platelet 14C-ATP and 14C-ADP had become releasable with thrombin (4.2 units/ml). Lysis of platelets did not occur, since less than 1% of the platelet-bound 51Cr from platelets labeled with this radioisotope appeared in the ambient fluid upon thrombin treatment. The 14C-ATP/14C-ADP ratio of the released adenine nucleotides (7.6) was similar to the 14C-ATP/14C-ADP ratio of the nonreleasable adenine nucleotides (7.1) 2 hr after the labeling with 14C-adenosine. However, upon prolonged incubation (10 hr) in vitro, the 14C-ATP/14C-ADP ratio of the releasable adenine nucleotides decreased to 2.7. The adenylate energy charge and the 14C- ATP/14C-ADP ratio of the metabolic adenine nucleotide pool did not change significantly during the time of observation. The 14C-ATP content of the platelets decreased by less than 1% hr of incubation at 37 degrees C. These observations are interpreted to mean that the 14C is transferred from the metabolically active, nonreleasable adenine nucleotide pool of human platelets into the releasable adenine nucleotide pool as ATP and is partially hydrolyzed there to yield ADP. The transfer of ATP across the storage organelle membrane of platelets may be similar to transport processes in the chromaffin cells of the adrenal medulla and may represent a general phenomenon in cells that possess storage organelles containing adenine nucleotides.

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Labeling of the releasable adenine nucleotides of washed human platelets

Blood ◽

10.1182/blood.v49.1.89.bloodjournal49189 ◽

1977 ◽

Vol 49 (1) ◽

pp. 89-99 ◽

Cited By ~ 1

Author(s):

HJ Reimers ◽

MA Packham ◽

JF Mustard

Keyword(s):

Adenine Nucleotide ◽

Adenine Nucleotides ◽

Energy Charge ◽

Human Platelets ◽

Transport Processes ◽

Adenylate Energy Charge ◽

Prolonged Incubation ◽

Atp Pool ◽

Adenine Nucleotide Pool

In rabbit platelets, the metabolically active ATP pool equilibrates with the releasable ATP pool within 1 day. The studies showing this have now been extended to human platelets. Human platelets labeled with 14C-adenosine or 14C-adenine were incubated for up to 10 hr in vitro at 37 degrees C. After 10 hr, about 12% of the total platelet 14C-ATP and 14C-ADP had become releasable with thrombin (4.2 units/ml). Lysis of platelets did not occur, since less than 1% of the platelet-bound 51Cr from platelets labeled with this radioisotope appeared in the ambient fluid upon thrombin treatment. The 14C-ATP/14C-ADP ratio of the released adenine nucleotides (7.6) was similar to the 14C-ATP/14C-ADP ratio of the nonreleasable adenine nucleotides (7.1) 2 hr after the labeling with 14C-adenosine. However, upon prolonged incubation (10 hr) in vitro, the 14C-ATP/14C-ADP ratio of the releasable adenine nucleotides decreased to 2.7. The adenylate energy charge and the 14C- ATP/14C-ADP ratio of the metabolic adenine nucleotide pool did not change significantly during the time of observation. The 14C-ATP content of the platelets decreased by less than 1% hr of incubation at 37 degrees C. These observations are interpreted to mean that the 14C is transferred from the metabolically active, nonreleasable adenine nucleotide pool of human platelets into the releasable adenine nucleotide pool as ATP and is partially hydrolyzed there to yield ADP. The transfer of ATP across the storage organelle membrane of platelets may be similar to transport processes in the chromaffin cells of the adrenal medulla and may represent a general phenomenon in cells that possess storage organelles containing adenine nucleotides.

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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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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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Acquired granular pool defect in stored platelets

Blood ◽

10.1182/blood.v57.2.203.bloodjournal572203 ◽

1981 ◽

Vol 57 (2) ◽

pp. 203-208

Author(s):

AK Rao ◽

S Niewiarowski ◽

S Murphy

Keyword(s):

Adenine Nucleotide ◽

Adenine Nucleotides ◽

Energy Charge ◽

Adenylate Energy Charge ◽

Platelet Factor ◽

Final Volume ◽

Before And After ◽

Functional Defect ◽

Metabolic Pool ◽

The Mean

Platelets stored as concentrates (PC) for 72 h at 22 degrees C develop a functional defect. Alterations in adenine nucleotides of platelets have been shown to affect platelet function. Adenine nucleotide content of platelets was measured before and after storage and a decrease of 27.1 /+- 1.7% (mean /+- SE) in ATP and 39.1 /+- 2.6% in ADP were found in 34 PC stored with final volume of 50 ml. In 11 PC with 30 ml volume. ATP and ADP decreased by 39.4 /+- 3.2% and 49.4 /+- 2.1%, respectively. The mean ATP to ADP ratio of stored platelets was significantly higher than of fresh platelets in both groups, suggesting a relatively greater decrease in granular than metabolic pool nucleotides. Levels of low affinity platelet factor 4 measured by radioimmunoassay in plasma from 0.86 /+- 0.08 microgram/ml in the fresh PC to 8.59 /+- 0.39 microgram/ml in stored PC, indicating a concomitant alpha-granular secretion. Labeling of metabolic pool with 14C-adenine revealed a mean decrease in the adenylate energy charge of 2.0 /+- 0.4% in 12 of 16 stored PC, with a lower ATP and higher hypoxanthine labeling in stored as compared to fresh platelets. These observations suggest that stored platelets develop an acquired defect in both dense and alpha granules and in their ability to maintain ATP homeostasis.

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Studies on the Platelet Defect in Alcoholism

Thrombosis and Haemostasis ◽

10.1055/s-0038-1647883 ◽

1975 ◽

Vol 33 (02) ◽

pp. 310-327 ◽

Cited By ~ 7

Author(s):

Dale H Cowan ◽

Richard C Graham

Keyword(s):

Platelet Function ◽

Adenine Nucleotide ◽

Specific Radioactivity ◽

Protein Composition ◽

Nucleotide Metabolism ◽

Supernatant Fraction ◽

Release Mechanism ◽

Adenine Nucleotide Metabolism ◽

Thrombocytopenic Patient

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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Hepatotrophic effects of insulin on glucose, glycogen, and adenine nucleotides in hepatocytes isolated from fed adult rats

Canadian Journal of Biochemistry ◽

10.1139/o80-136 ◽

1980 ◽

Vol 58 (10) ◽

pp. 1004-1011 ◽

Cited By ~ 2

Author(s):

Khursheed N. Jeejeebhoy ◽

Joseph Ho ◽

Rajni Mehra ◽

Alan Bruce-Robertson

Keyword(s):

Adenine Nucleotide ◽

Adenine Nucleotides ◽

Energy Charge ◽

Close Correlation ◽

Adult Rats ◽

Fed State ◽

Adenine Nucleotide Pool ◽

Intracellular Glucose

In vivo observations have suggested that there is an hepatotrophic effect of insulin. By contrast, subsequent in vitro work, using the isolated perfused liver system, showed no effect or indeterminate effects of insulin on the transport of glucose into the hepatocyte. However because this system may not have endured long enough to show such an influence we explored the transport of glucose using a 48-h suspension culture of hepatocytes isolated from young adult fed rats, the suspension being infused continuously with insulin at a rate approximating the maximum entering portal blood in the fed state. (In a separate study phloridzin was added after 2 h of incubation.) DNA, intracellular glucose and its inward transport, glycogen, and the adenine nucleotides were measured at intervals. By comparison with control or untreated cells, insulin-treated cells showed significantly more DNA and intracellular glucose, and the differences were abolished by phloridzin. Glucose transport rates fell to low values in untreated controls and still lower with insulin plus phloridzin. but the initial rate was maintained to the end (48 h) by insulin alone. Results for glycogen were similar to those for intracellular glucose. There was a close correlation (r = 0.96) between these two. The total adenine nucleotide pool and the concentration of ATP were maintained for about 24 h and fell to half their initial values by 48 h. Insulin had increased these concentrations significantly by 6 h. Although concentrations of ADP and AMP decreased gradually in all groups of cells, insulin enhanced the level of ADP by 12 h but had no measurable effect on that of AMP. The energy charge increased slightly throughout incubation but more so (by 6 h) in the presence of insulin. In conclusion the data support the concept that in the longer term (> 12 h) insulin in the portal circulation maintains the characteristic free permeability of the hepatocyte to glucose and this permits a variety of effects related to glucose entry into the hepatocyte.

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The Effect of Cold on Platelets. III. Adenine Nucleotide Metabolism After Brief Storage at Cold Temperature

Blood ◽

10.1182/blood.v42.4.557.557 ◽

1973 ◽

Vol 42 (4) ◽

pp. 557-564 ◽

Cited By ~ 7

Author(s):

Herman E. Kattlove ◽

Dorothy Mormino

Keyword(s):

Connective Tissue ◽

Prostaglandin E1 ◽

Room Temperature ◽

Adenine Nucleotide ◽

Platelet Rich Plasma ◽

Adenine Nucleotides ◽

Nucleotide Metabolism ◽

Immunoglobulin M ◽

Release Reaction ◽

Adenine Nucleotide Metabolism

Abstract The effect of cold on platelet adenine nucleotide (PAN) metabolism was studied. Spontaneous aggregation which occurs when chilled platelet-rich plasma (PRP) is simultaneously warmed and stirred was not accompanied by the changes in adenine nucleotides associated with the release reaction. Connective tissue caused the release of the same amount of ADP and conversion of equal amounts of ATP to IMP and hypoxanthine in cold-stored platelets as it did in room temperature stored platelets. However, cold did have an important effect on PAN. In PRP stored at cold (0° C, 3° C) temperatures and warmed up to 37° C in the presence of 3H adenine, there was an increase in the conversion of adenine to its metabolites and ultimately to hypoxanthine as compared to PRP stored at warmer temperatures. This effect could not be prevented by ouabain, prostaglandin E1, antibody to immunoglobulin M or adenosine.

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Increases of cell ATP produced by exogenous adenine nucleotides in isolated rabbit kidney tubules

AJP Renal Physiology ◽

10.1152/ajprenal.1986.250.4.f720 ◽

1986 ◽

Vol 250 (4) ◽

pp. F720-F733 ◽

Cited By ~ 1

Author(s):

J. M. Weinberg ◽

H. D. Humes

Keyword(s):

Cell Injury ◽

Adenine Nucleotide ◽

Adenine Nucleotides ◽

Recovery Period ◽

Nucleotide Metabolism ◽

Rabbit Kidney ◽

Kidney Tubules ◽

Atp Levels ◽

Adenine Nucleotide Metabolism ◽

Functional Consequences

The effects of exogenous nucleotides on adenine nucleotide metabolism and cell cation levels in normal and O2-deprived isolated rabbit kidney tubules were studied to gain insight into ways in which exogenous nucleotides could contribute to ameliorating O2 deprivation-induced injury. In control oxygenated tubules, 250 microM exogenous ATP, ADP, or AMP resulted in two- to threefold increases of cell ATP over 75-90 min of incubation and smaller relative increases of ADP and AMP. GTP was not increased. Exogenous adenosine, inosine, and hypoxanthine were substantially less effective at increasing intracellular nucleotides than equimolar concentrations of exogenous nucleotides. Nucleotide-treated cells had higher levels of Ca2+ and Mg2+ than untreated cells. Treatment of O2-deprived tubules with exogenous Mg-ATP improved recovery of ATP levels following O2 deprivation, and tubules with mild injury increased their ATP levels to supranormal values such as those seen in control oxygenated tubules treated with nucleotides. Increases of tubule cell ATP levels required ongoing oxidative metabolism and thus were not evident until the reoxygenation recovery period. Exogenous ATP produced some improvement of other injury-associated metabolic parameters but did not substantially alter the overall pattern of tubule susceptibility to lethal cell injury. Allopurinol did not affect the behavior of oxygenated or O2-deprived tubules irrespective of the presence of exogenous ATP. These data clarify the potential for manipulating intracellular ATP levels with exogenous nucleotides and the functional consequences of such manipulation in oxygenated and O2-deprived renal tubule cells.

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Acquired granular pool defect in stored platelets

Blood ◽

10.1182/blood.v57.2.203.203 ◽

1981 ◽

Vol 57 (2) ◽

pp. 203-208 ◽

Cited By ~ 34

Author(s):

AK Rao ◽

S Niewiarowski ◽

S Murphy

Keyword(s):

Adenine Nucleotide ◽

Adenine Nucleotides ◽

Energy Charge ◽

Adenylate Energy Charge ◽

Platelet Factor ◽

Final Volume ◽

Before And After ◽

Functional Defect ◽

Metabolic Pool ◽

The Mean

Abstract Platelets stored as concentrates (PC) for 72 h at 22 degrees C develop a functional defect. Alterations in adenine nucleotides of platelets have been shown to affect platelet function. Adenine nucleotide content of platelets was measured before and after storage and a decrease of 27.1 /+- 1.7% (mean /+- SE) in ATP and 39.1 /+- 2.6% in ADP were found in 34 PC stored with final volume of 50 ml. In 11 PC with 30 ml volume. ATP and ADP decreased by 39.4 /+- 3.2% and 49.4 /+- 2.1%, respectively. The mean ATP to ADP ratio of stored platelets was significantly higher than of fresh platelets in both groups, suggesting a relatively greater decrease in granular than metabolic pool nucleotides. Levels of low affinity platelet factor 4 measured by radioimmunoassay in plasma from 0.86 /+- 0.08 microgram/ml in the fresh PC to 8.59 /+- 0.39 microgram/ml in stored PC, indicating a concomitant alpha-granular secretion. Labeling of metabolic pool with 14C-adenine revealed a mean decrease in the adenylate energy charge of 2.0 /+- 0.4% in 12 of 16 stored PC, with a lower ATP and higher hypoxanthine labeling in stored as compared to fresh platelets. These observations suggest that stored platelets develop an acquired defect in both dense and alpha granules and in their ability to maintain ATP homeostasis.

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