Free Adenosine Diphosphate as an Intermediary in the Phosphorylation by Creatine Phosphate of Adenosine Diphosphate Bound to Actin

PAF-acether (platelet-activating factor) has been recently identified as l-O-alkyl-2-acetyl-sn-glyceryl-phosphorylcholine, and later chemically synthetized. Platelets form PAF-acether upon stimulation with the calcium ionophore A 23187 or with more physiological stimuli such as thrombin or collagen. By contrast, arachidonic acid (AA) and adenosine diphosphate (ADP) do not trigger formation of PAF-acether. Since 1) PAF-acether is a phospholipid derivative and 2) aggregating agents which trigger PAF-acether formation are potent platelet PLA2 stimulators, we speculated that PLA2 could be implicated in its formation.Rabbit washed platelets were incubated at 37°C in the presence of thrombin (2.5 U/ml) or of ionophore A 23187 (2.5 uM) for 7 min and ethanol (80 % final) was added. After centrifugation, the supernatant was evaporated and concentrated. The extract was tested for its aggregating property on rabbit washed platelets preincubated with a cyclo-oxygenase inhibitor (aspirin) and an ADP scavenging system (creatine phosphate and creatine phosphokinase).In the presence of calcium chelating agents such as EDTA (5 mM) and EGTA (5 mM) most of the synthesis of PAF-acether was suppressed (93 % and 100 % of inhibition respectively). Dibutyryl cyclic AMP (5 mM) also suppressed PAF-acether formation from platelets challenged by thrombin or by the ionophore A 23187 (100 % and 62 % inhibition respectively). Bromophenacyl bromide (0.1 mM) and compound CB 874 (0.1 mM) proved also to be very potent inhibitors of PAF-acether synthesis (100 % inhibition both). All these drugs are well-known platelet PLA2 inhibitors. Upon stimulation platelets also form a deacetylated PAF-acether (lyso- PAF-acether) which could be the direct precursor of PAF-acether. The release of lyso-PAF-acether and the blockade of PAF-acether formation by various molecules having in common a PLA- inhibitory activity lead us to conclude that a PLA2 may be implicated in PAF-acether formation from platelets. Alternative explanations include the possibility that the various inhibitors act on other membrane-related sites.

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Comparison in control and severely diabetic, alloxanized rats of phosphate fractions, glycogen and fat

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1959.196.6.1246 ◽

1959 ◽

Vol 196 (6) ◽

pp. 1246-1249 ◽

Cited By ~ 2

Author(s):

Clarissa H. Beatty ◽

Ruth D. Peterson ◽

Rose Mary Bocek ◽

Edward S. West

Keyword(s):

Body Weight ◽

Inorganic Phosphate ◽

Trichloroacetic Acid ◽

Adenosine Diphosphate ◽

Creatine Phosphate ◽

Soluble Phosphate ◽

Total Acid ◽

Control Series ◽

Noncollagenous Protein ◽

Total Muscle

Homogeneous aliquots of powdered muscle were analyzed and levels of constituents calculated on a fat-free basis. When compared to muscle from control rats, muscle from severely diabetic, alloxanized rats showed a decrease in creatine phosphate, total acid soluble phosphate and total phosphate, with no change in inorganic phosphate, adenosine diphosphate plus adenosine triphosphate, or total acid soluble phosphate minus 7-minute hydrolyzable phosphate, creatine, noncollagenous protein or total nitrogen. There was an increase in the trichloroacetic acid extractable glycogen value in the muscle of the alloxan diabetic as compared to the control series. The concentration of fat in the muscle itself was higher in the diabetic than in the control series, although the total muscle fat had decreased in the diabetic series due to the decrease in percentage of body weight represented by muscle.

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Participation of ADP in the binding of fibrinogen to thrombin- stimulated platelets

Blood ◽

10.1182/blood.v56.3.553.553 ◽

1980 ◽

Vol 56 (3) ◽

pp. 553-555 ◽

Cited By ~ 46

Author(s):

EF Plow ◽

GA Marguerie

Keyword(s):

Creatine Phosphokinase ◽

Adenosine Diphosphate ◽

Creatine Phosphate ◽

Human Platelets ◽

Serotonin Release ◽

Fibrinogen Binding ◽

Platelet Secretion

Abstract Thrombin and adenosine diphosphate (ADP) supported the binding of 125I- fibrinogen to washed human platelets with similar kinetics and affinity. Platelet secretion, as measured by 14C-serotonin release, and fibrinogen binding exhibited an identical dependence on thrombin concentration. Enzymatic removal of ADP with apyrase or creatine phosphate/creatine phosphokinase (CP/CPK) from thrombin-stimulated platelets markedly inhibited 125I-fibrinogen binding, but pretreatment of platelets with CP/CPK prior to thrombin stimulation was without effect. Thus, ADP, released from the platelet, participates in the binding of fibrinogen to thrombin-stimulated platelets.

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Zinc-induced platelet aggregation is mediated by the fibrinogen receptor and is not accompanied by release or by thromboxane synthesis

Blood ◽

10.1182/blood.v66.1.213.213 ◽

1985 ◽

Vol 66 (1) ◽

pp. 213-219 ◽

Cited By ~ 29

Author(s):

P Heyns A du ◽

A Eldor ◽

R Yarom ◽

G Marx

Keyword(s):

Platelet Aggregation ◽

Dense Body ◽

Platelet Rich Plasma ◽

Adenosine Monophosphate ◽

Adenosine Diphosphate ◽

Creatine Phosphate ◽

Calcium Flux ◽

Fibrinogen Receptor ◽

Induced Aggregation

Abstract We demonstrate that zinc (0.1 to 0.3 mmol/L) induces aggregation of washed platelet suspensions. Higher concentrations (1 to 3 mmol/L) of zinc were needed to aggregate platelets in platelet-rich plasma obtained from blood anticoagulated with low-molecular-weight heparin, probably due to the binding of zinc to the plasma proteins. Zinc- induced aggregation of normal washed platelets required added fibrinogen and no aggregation occurred with thrombasthenic platelets or with normal platelets pretreated with a monoclonal antibody (10E5) that blocks the platelet fibrinogen receptor. These data indicate that the platelet membrane fibrinogen receptor-glycoproteins IIb and IIIa mediate the effect of zinc. Zinc-induced aggregation was blocked by the agent TMB-8, which interferes with the internal calcium flux, and by prostacyclin, which elevates platelet cyclic adenosine monophosphate levels. Zinc-induced aggregation was not accompanied by thromboxane synthesis or by the secretion of dense-body serotonin and was not affected by preexposure of platelets to acetylsalicylic acid. Experiments with creatine phosphate/creatine phosphokinase showed that the zinc effect on platelets was independent of extracellular adenosine diphosphate (ADP). Zinc had an additive effect when platelet aggregation was stimulated with subthreshhold concentrations of collagen or ADP. Together with the known effects of nutritional zinc on in vivo bleeding, on platelet aggregation, and on lipid metabolism, the results suggest that zinc may have an important bearing on normal hemostasis, thrombosis, and atherosclerosis.

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Platelet agonist synergism by the acute phase reactant C-reactive protein

Blood ◽

10.1182/blood.v65.2.264.bloodjournal652264 ◽

1985 ◽

Vol 65 (2) ◽

pp. 264-269

Author(s):

BA Fiedel

Keyword(s):

Acute Phase ◽

Creatine Phosphokinase ◽

Platelet Rich Plasma ◽

Adenosine Diphosphate ◽

Creatine Phosphate ◽

Acute Phase Reactant ◽

C Reactive Protein ◽

Reactive Protein ◽

Phase Reactant ◽

Irreversible Aggregation

C-reactive protein is the prototypic acute phase reactant. A self- complexed form (H-CRP) can induce isolated platelets to undergo aggregation, secretion of dense and alpha-granule constituents, and generation of thromboxane A2, but fails to function in platelet-rich plasma (PRP) as a direct agonist. In contrast, when PRP was activated with an amount of adenosine diphosphate (ADP) that produced only reversible platelet aggregation, the presence of H-CRP resulted in irreversible aggregation and the secretion of adenosine triphosphate (ATP). Following a maximum stimulus with ADP alone, where platelet secretion occurred late during the aggregation response, the presence of H-CRP shifted and increased the secretory burst to a time simultaneous with the onset of aggregation. This hypersecretion required H-CRP to be present prior to platelet stimulation or to be added within 15 to 30 seconds following the addition of ADP. H-CRP also potentiated platelet activation stimulated with epinephrine, thrombin, and collagen. When the synergism generated in PRP by H-CRP in the presence of ADP or epinephrine was compared to the synergism similarly produced by aggregated human IgG, collagen, or thrombin, it more closely resembled that of collagen, as reflected by the kinetics and characteristics of synergism and sensitivity to creatine phosphate/creatine phosphokinase or 5,8,11,14-eicosatetraynoic acid. These data provide a philosophically ideal niche for the acute phase (and C-reactive protein) in that a platelet-directed activity associated with this acute phase reactant is not utilized unless platelets are otherwise challenged.

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Human placenta as a convenient source of creatine kinase BB.

Clinical Chemistry ◽

10.1093/clinchem/29.8.1537 ◽

1983 ◽

Vol 29 (8) ◽

pp. 1537-1539 ◽

Cited By ~ 5

Author(s):

J P Steghens ◽

I Maire ◽

M Mathieu

Keyword(s):

Creatine Kinase ◽

Human Placenta ◽

Catalytic Properties ◽

Adenosine Diphosphate ◽

Creatine Phosphate ◽

Abdominal Muscle ◽

Creatine Kinase Isoenzyme ◽

Creatine Kinase Bb ◽

Creatine Kinase Isoenzymes

Abstract We demonstrate that human placenta is a convenient source of creatine kinase isoenzyme BB. We compare the physicochemical and catalytic properties with those of other creatine kinase isoenzymes: purified human abdominal muscle MM and brain BB. We also describe a stabilizing medium for creatine kinase BB. Human placental and brain BB have similar catalytic properties, the respective Km values for creatine phosphate being 0.66 and 0.56 mmol/L and for adenosine diphosphate 89 and 70 nmol/L.

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Creatine kinase response surfaces explored by use of factorial experiments and simplex maximization.

Clinical Chemistry ◽

10.1093/clinchem/29.5.793 ◽

1983 ◽

Vol 29 (5) ◽

pp. 793-799 ◽

Cited By ~ 2

Author(s):

D M Fast ◽

E J Sampson ◽

V S Whitner ◽

M Ali

Keyword(s):

Creatine Kinase ◽

Response Surface ◽

Kinase Activity ◽

Adenosine Diphosphate ◽

Creatine Phosphate ◽

Creatine Kinase Activity ◽

Response Surfaces ◽

Optimal Conditions ◽

Reaction Conditions ◽

Sensitivity Reaction

Abstract We conducted a five-component, five-level response-surface experiment to optimize the pH and the concentrations of magnesium, creatine phosphate, adenosine diphosphate, and buffer in an assay for creatine kinase. Under optimal conditions, creatine kinase activity was about 5% greater than that obtained with a previously reported assay (Clin Chem 23: 1569, 1977). We also applied a simplex maximization algorithm to the response-surface equation to locate areas of maximum sensitivity. Reaction conditions for two such areas were found, each yielding approximately 11% more activity than with the previously reported method.

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Platelet agonist synergism by the acute phase reactant C-reactive protein

Blood ◽

10.1182/blood.v65.2.264.264 ◽

1985 ◽

Vol 65 (2) ◽

pp. 264-269 ◽

Cited By ~ 17

Author(s):

BA Fiedel

Keyword(s):

Acute Phase ◽

Creatine Phosphokinase ◽

Platelet Rich Plasma ◽

Adenosine Diphosphate ◽

Creatine Phosphate ◽

Acute Phase Reactant ◽

C Reactive Protein ◽

Reactive Protein ◽

Phase Reactant ◽

Irreversible Aggregation

Abstract C-reactive protein is the prototypic acute phase reactant. A self- complexed form (H-CRP) can induce isolated platelets to undergo aggregation, secretion of dense and alpha-granule constituents, and generation of thromboxane A2, but fails to function in platelet-rich plasma (PRP) as a direct agonist. In contrast, when PRP was activated with an amount of adenosine diphosphate (ADP) that produced only reversible platelet aggregation, the presence of H-CRP resulted in irreversible aggregation and the secretion of adenosine triphosphate (ATP). Following a maximum stimulus with ADP alone, where platelet secretion occurred late during the aggregation response, the presence of H-CRP shifted and increased the secretory burst to a time simultaneous with the onset of aggregation. This hypersecretion required H-CRP to be present prior to platelet stimulation or to be added within 15 to 30 seconds following the addition of ADP. H-CRP also potentiated platelet activation stimulated with epinephrine, thrombin, and collagen. When the synergism generated in PRP by H-CRP in the presence of ADP or epinephrine was compared to the synergism similarly produced by aggregated human IgG, collagen, or thrombin, it more closely resembled that of collagen, as reflected by the kinetics and characteristics of synergism and sensitivity to creatine phosphate/creatine phosphokinase or 5,8,11,14-eicosatetraynoic acid. These data provide a philosophically ideal niche for the acute phase (and C-reactive protein) in that a platelet-directed activity associated with this acute phase reactant is not utilized unless platelets are otherwise challenged.

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Released adenosine diphosphate stabilizes thrombin-induced human platelet aggregates

Blood ◽

10.1182/blood.v75.5.1081.bloodjournal7551081 ◽

1990 ◽

Vol 75 (5) ◽

pp. 1081-1086 ◽

Cited By ~ 1

Author(s):

M Cattaneo ◽

MT Canciani ◽

A Lecchi ◽

RL Kinlough-Rathbone ◽

MA Packham ◽

...

Keyword(s):

Binding Sites ◽

Creatine Phosphokinase ◽

Adenosine Diphosphate ◽

Creatine Phosphate ◽

Human Platelets ◽

Fibrinogen Binding ◽

Normal Human ◽

Platelet Aggregates ◽

Induced Aggregation ◽

Selective Impairment

Normal human platelets aggregated by thrombin undergo the release reaction and are not readily deaggregated by the combination of inhibitors hirudin, chymotrypsin, and prostaglandin E1 (PGE1). In contrast, thrombin-induced aggregates of platelets from patients with delta-storage pool deficiency (delta-SPD), which lack releasable nucleotides, are readily deaggregated by the same combination of inhibitors. The ease with which delta-SPD platelets are deaggregated is caused by the lack of stabilizing effects of released ADP, since: (1) exogenous adenosine diphosphate (ADP) (10 mumol/L), but not serotonin (2 mumol/L), abolishes the ability of these inhibitors to deaggregate delta-SPD platelets; (2) thrombin-induced aggregates of platelets from a patient (V.R.) (whose platelets have a severe, selective impairment of sensitivity to ADP, but normal amounts of releasable nucleotides) can be readily deaggregated, and addition of ADP does not stabilize the platelet aggregates; (3) apyrase or creatine phosphate (CP)/creatine phosphokinase (CPK), added before thrombin, make control platelets more easily deaggregated by hirudin, chymotrypsin, and PGE1, and do not change the deaggregation response of delta-SPD platelets and of V.R.'s platelets. Thrombin-induced aggregation and release of beta- thromboglobulin in control, delta-SPD, and in V.R.'s platelets was similar and not inhibited by apyrase or CP/CPK. The stabilizing effect of ADP on platelet aggregates is specific, since epinephrine in the presence of apyrase to remove traces of released ADP does not stabilize the aggregates of control, delta-SPD, or of V.R.'s platelets. Because epinephrine increases fibrinogen binding to thrombin-stimulated platelets to a greater extent than ADP, but does not stabilize the aggregates, it is unlikely that the additional fibrinogen binding sites induced by ADP have a major role in inhibiting deaggregation by the combination of inhibitors.

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Amelioration of Energy Metabolism by Melatonin in Skeletal Muscle of Rats With LPS Induced Endotoxemia

Physiological Research ◽

10.33549/physiolres.933282 ◽

2016 ◽

pp. 833-842 ◽

Cited By ~ 5

Author(s):

E. OZKOK ◽

H. YORULMAZ ◽

G. ATES ◽

A. AKSU ◽

N. BALKIS ◽

...

Keyword(s):

Skeletal Muscle ◽

Energy Metabolism ◽

Muscle Tissue ◽

High Performance ◽

Succinic Dehydrogenase ◽

Adenosine Monophosphate ◽

Adenosine Diphosphate ◽

Creatine Phosphate ◽

Before And After ◽

Hematoxylin And Eosin

In the literature, few studies have investigated the effects of melatonin on energy metabolism in skeletal muscle in endotoxemia. We investigated the effects of melatonin on tissue structure, energy metabolism in skeletal muscle, and antioxidant level of rats with endotoxemia. We divided rats into 4 groups, control, lipopolysaccharide (LPS) (20 mg/kg, i.p., single dose), melatonin (10 mg/kg, i.p., three times), and melatonin + LPS. Melatonin was injected i.p. 30 min before and after the 2nd and 4th hours of LPS injection. Antioxidant status was determined by glutathione (GSH) measurement in the blood. Muscle tissue was stained using modified Gomori trichrome (MGT), succinic dehydrogenase (SDH), and cytochrome oxidase (COX) and histological scored. Also the sections were then stained with hematoxylin and eosin. The stained sections were visualized and photographed. Creatine, creatine phosphate, adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP) levels were investigated using high performance liquid chromatography (HPLC) in muscle tissue. In the Melatonin + LPS group, blood GSH levels were increased compared with the LPS group (P<0.01). Melatonin reduced myopathic changes in the LPS group according to the histopathologic findings. In addition, ATP values were increased compared with the LPS group (P<0.05). Our findings showed melatonin treatment prevented muscle damage by increasing ATP and GSH levels in rats with LPS induced endotoxemia.

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