scholarly journals The influence of vitamin E quinone on platelet structure, function, and biochemistry

Blood ◽  
1980 ◽  
Vol 55 (6) ◽  
pp. 907-914 ◽  
Author(s):  
AC Cox ◽  
GH Rao ◽  
JM Gerrard ◽  
JG White
Keyword(s):  
Arachidonic Acid ◽  
Vitamin E ◽  
Platelet Function ◽  
Calcium Release ◽  
Adenine Nucleotides ◽  
Antithrombotic Agent ◽  
In Vivo Effects ◽  
Natural Metabolite

Abstract Although the effects of vitamin E on platelet function have been investigated in vivo and in vitro, vitamin E quinone, a natural metabolite of vitamin E, has been virtually overlooked. This oxidized form of vitamin E inhibits platelet aggregation and secretion induced by various aggregating agents more effectively than vitamin E by a magnitude of 5–10-fold. Vitamin E and vitamin E quinone do not alter platelet ultrastructure or cellular concentrations of serotonin and adenine nucleotides, including cAMP. Inhibition of aggregation by vitamin E quinone occurs in the absence of detectable reduction of vitamin E quinone or oxidation of vitamin E and is readily reversed by washing the platelet. Only vitamin E quinone prevents arachidonic acid release and slightly inhibits cyclooxygenase, whereas both agents partially prevent calcium release from a platelet subcellular organelle. Vitamin E quinone also inhibited synthesis of prostacyclin by endothelial cells with basal synthesis in the presence of external arachidonic acid being less affected than thrombin-stimulated PGI2 production. The greater potency of vitamin E quinone in suppressing platelet function compared to vitamin E suggests that this quinone metabolite may be the better antithrombotic agent and possibly responsible for in vivo effects previously attributed to vitamin E.

scholarly journals The influence of vitamin E quinone on platelet structure, function, and biochemistry

Blood ◽  
1980 ◽  
Vol 55 (6) ◽  
pp. 907-914
Author(s):  
AC Cox ◽  
GH Rao ◽  
JM Gerrard ◽  
JG White
Keyword(s):  
Arachidonic Acid ◽  
Vitamin E ◽  
Platelet Function ◽  
Calcium Release ◽  
Adenine Nucleotides ◽  
Antithrombotic Agent ◽  
In Vivo Effects ◽  
Natural Metabolite

Although the effects of vitamin E on platelet function have been investigated in vivo and in vitro, vitamin E quinone, a natural metabolite of vitamin E, has been virtually overlooked. This oxidized form of vitamin E inhibits platelet aggregation and secretion induced by various aggregating agents more effectively than vitamin E by a magnitude of 5–10-fold. Vitamin E and vitamin E quinone do not alter platelet ultrastructure or cellular concentrations of serotonin and adenine nucleotides, including cAMP. Inhibition of aggregation by vitamin E quinone occurs in the absence of detectable reduction of vitamin E quinone or oxidation of vitamin E and is readily reversed by washing the platelet. Only vitamin E quinone prevents arachidonic acid release and slightly inhibits cyclooxygenase, whereas both agents partially prevent calcium release from a platelet subcellular organelle. Vitamin E quinone also inhibited synthesis of prostacyclin by endothelial cells with basal synthesis in the presence of external arachidonic acid being less affected than thrombin-stimulated PGI2 production. The greater potency of vitamin E quinone in suppressing platelet function compared to vitamin E suggests that this quinone metabolite may be the better antithrombotic agent and possibly responsible for in vivo effects previously attributed to vitamin E.

In vitro and in vivo effects of selenium and selenium with vitamin E on platelet functions in diabetic rats relationship to platelet sorbitol and fatty acid distribution

1996 ◽  
Vol 55 (3) ◽  
pp. 263-277 ◽  
Author(s):  
Christelle Douillet ◽  
Muriel Bost ◽  
Michèle Accominotti ◽  
Françoise Borson-Chazot ◽  
Maryvonne Ciavatti
Keyword(s):  
Fatty Acid ◽  
Vitamin E ◽  
Fatty Acid Distribution ◽  
Diabetic Rats ◽  
In Vivo Effects ◽  
Platelet Functions

Selenium Dependent Glutathione Peroxidase: A Physiological Regulatory System for Platelet Function

1990 ◽  
Vol 64 (02) ◽  
pp. 312-318 ◽  
Author(s):  
G Perona ◽  
R Schiavon ◽  
G C Guidi ◽  
D Veneri ◽  
P Minuz
Keyword(s):  
Platelet Aggregation ◽  
Glutathione Peroxidase ◽  
Platelet Function ◽  
Bleeding Time ◽  
Adenine Nucleotides ◽  
Physiological Mechanism ◽  
Regulatory System ◽  
Progressive Increase

SummaryIn human platelets the selenoenzyme glutathione peroxidase (GSH-Px) acts as a scavenger of the peroxides generated during the burst of arachidonic acid (AA) metabolism. Such a mechanism inhibits the biosynthesis of both thromboxane A2 (TXA2) and lipoxygenase products. The same mechanism is not effective on the prostacyclin (PGI2) biosynthesis from cultured endothelial cells. In order to evaluate this effect in vivo, besides in vitro, we activated the enzyme in eight normal volunteers by increasing their daily Se intake for 8 weeks, monitoring: platelet GSH-Px activity, platelet aggregation induced by A A and U 44069, and concurrent malondialdehyde (MDA) and thromboxane B2 (TXB2) production, urinary excretion of renal and systemic TXA2 and PGI2 metabolites, platelet enzyme activities of the hexose monophosphate pathway and glutathione content, platelet adenine nucleotides, bleeding time, plasma Se concentration. We found: a) progressive platelet GSH-Px activation by Se paralleling an enhancement of platelet aggregation threshold values for AA, but not for U 44069; b) concurrent inhibition of platelet biosynthesis of TXA2 both in vitro and in vivo while the biosynthesis of systemic prostacyclin was unaffected; c) a progressive increase in the bleeding time, unmodified by aspirin. In conclusion, we believe that Se-dependent GSH-Px represents a physiological mechanism regulating the biosynthesis of prostanoids with implications in platelet function and that a Se dietary supplement might be considered in the prevention of arterial thrombosis.

In vitro and in vivo effects of a peptide mimetic (SC-47643) of RGD as an antiplatelet and antithrombotic agent

1991 ◽  
Vol 62 (5) ◽  
pp. 567-578 ◽  
Author(s):  
N.S. Nicholson ◽  
S.G. Panzer-Knodle ◽  
A.K. Salyers ◽  
B.B. Taite ◽  
L.W. King ◽  
...  
Keyword(s):  
Antithrombotic Agent ◽  
Peptide Mimetic ◽  
In Vivo Effects

In vivo and in vitro Effects of Zinc Oxide-Eugenol (ZOE) on Biosynthesis of Cyclo-oxygenase Products in Rat Dental Pulp

1988 ◽  
Vol 67 (8) ◽  
pp. 1092-1096 ◽  
Author(s):  
S. Hashimoto ◽  
K. Uchiyama ◽  
M. Maeda ◽  
K. Ishitsuka ◽  
K. Furumoto ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Arachidonic Acid ◽  
Dental Pulp ◽  
Zinc Oxide Eugenol ◽  
In Vitro Effects ◽  
Artificial Cavity ◽  
In Vivo Effects ◽  
Made In

To determine the in vivo effects of a zinc oxide-eugenol mixture (ZOE) on the cyclo-oxygenase system in dental pulp, we used radioimmunoassay to measure the levels of prostaglandin E2 (PGE2), 13,14-dihydro-15-keto-PG (DHK-PG), thromboxane B2 (TXB2), and 6-keto-PGF1α in the dental pulp of rats. When the dental pulp was irritated by a hole made in the dentin of the mandibular incisors without use of any coolants, the levels of these cyclo-oxygenase products in the pulp were increased to, respectively, 2.8, 1.7, 10.0, and 2.6 times those in the normal pulp at six hr after treatment. In contrast, these increases in cyclo-oxygenase products disappeared immediately when the artificial cavity in the dentin was filled with ZOE (P/L; 1 g/0.25 mL), but were not altered when the cavity was filled with zinc oxide-water (ZOW, 1 g/1.5 mL). Most of the eugenol portion of ZOE was released into the pulp within two hr after the cavity was filled with ZOE. The maximal eugenol content was 35 pmol per mg of pulp. Furthermore, when the cavity was filled either with ZOE or by the addition of 10 μmol/L eugenol to the pulp homogenate, biosynthesis of 14C-6-keto-PGF1α, PGF2α, and PGE 2 from 14C-arachidonic acid in the homogenate was inhibited. These results suggest that eugenol released from ZOE in the cavity prepared in the dentin inhibited the biosynthesis of cyclo-oxygenase products during pulp irritation.

Effects of Vitamin E Administration on Platelet Function and Serum Lipid Peroxides in DOCA-Salt Hypertensive Rats

1991 ◽  
Vol 65 (04) ◽  
pp. 411-414 ◽  
Author(s):  
Keizo Umegaki ◽  
Hiromi Saegusa ◽  
Masato Kurokawa ◽  
Tomio Ichikawa
Keyword(s):  
Vitamin E ◽  
Platelet Function ◽  
Serum Lipid ◽  
Lipid Peroxide ◽  
Lipid Peroxides ◽  
Hypertensive Rats ◽  
Serotonin Content ◽  
Serum Lipid Peroxide ◽  
Salt Hypertension

SummaryEffects of vitamin E on platelet function and serum lipid peroxide levels were investigated in DOCA-salt hypertensive rats. In the hypertensive rats, ADP- and collagen-induced platelet aggregation in whole blood were markedly attenuated and accompanied by a reduction of serotonin content as compared with the normotensive controls. These facts indicated the appearance of exhausted platelets, which have already been activated in vivo, due to the hypertension. Platelet vitamin E levels were decreased by 50%, while serum lipid peroxide levels were increased 3.6-fold in the hypertensive rats. Vitamin E administration (10 times the dietary intake) during the experimental periods did not influence either the aggregability or the serotonin content of platelets from the hypertensive rats. However, vitamin E administration significantly prevented the elevation of serum tipid peroxides due to the hypertension. These results suggest that vitamin E administration has little effect on platelet activation in vivo due to DOCA-salt hypertension.

A Comparison of the Effect of Decorsin and Two Disintegrins, Albolabrin and Eristostatin, on Platelet Function

1995 ◽  
Vol 74 (05) ◽  
pp. 1316-1322 ◽  
Author(s):  
Mary Ann McLane ◽  
Jagadeesh Gabbeta ◽  
A Koneti Rao ◽  
Lucia Beviglia ◽  
Robert A Lazarus ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Platelet Function ◽  
Sequence Similarity ◽  
Platelet Aggregation Inhibitors ◽  
Antiplatelet Drug ◽  
Rgd Sequence ◽  
Fibrinogen Receptor ◽  
Activated Platelets

SummaryNaturally-occurring fibrinogen receptor antagonists and platelet aggregation inhibitors that are found in snake venom (disintegrins) and leeches share many common features, including an RGD sequence, high cysteine content, and low molecular weight. There are, however, significant selectivity and potency differences. We compared the effect of three proteins on platelet function: albolabrin, a 7.5 kDa disintegrin, eristostatin, a 5.4 kDa disintegrin in which part of the disintegrin domain is deleted, and decorsin, a 4.5 kDa non-disintegrin derived from the leech Macrobdella decora, which has very little sequence similarity with either disintegrin. Decorsin was about two times less potent than albolabrin and six times less potent than eristostatin in inhibiting ADP- induced human platelet aggregation. It had a different pattern of interaction with glycoprotein IIb/IIIa as compared to the two disintegrins. Decorsin bound with a low affinity to resting platelets (409 nM) and to ADP-activated platelets (270 nM), and with high affinity to thrombin- activated platelets (74 nM). At concentrations up to 685 nM, it did not cause expression of a ligand-induced binding site epitope on the (β3 subunit of the GPIIb/IIIa complex. It did not significantly inhibit isolated GPIIb/IIIa binding to immobilized von Willebrand Factor. At low doses (1.5-3.0 μg/mouse), decorsin protected mice against death from pulmonary thromboembolism, showing an effect similar to eristostatin. This suggested that decorsin is a much more potent inhibitor of platelet aggregation in vivo than in vitro, and it may have potential as an antiplatelet drug.

Superoxide, Xanthine Oxidase and Platelet Reactions: Further Studies on Mechanisms by which Oxidants Influence Platelets

1981 ◽  
Vol 45 (03) ◽  
pp. 290-293 ◽  
Author(s):  
Peter H Levine ◽  
Danielle G Sladdin ◽  
Norman I Krinsky
Keyword(s):  
Superoxide Dismutase ◽  
Cytochrome C ◽  
Xanthine Oxidase ◽  
Direct Effect ◽  
Platelet Function ◽  
Experimental Conditions ◽  
Release Reaction

SummaryIn the course of studying the effects on platelets of the oxidant species superoxide (O- 2), Of was generated by the interaction of xanthine oxidase plus xanthine. Surprisingly, gel-filtered platelets, when exposed to xanthine oxidase in the absence of xanthine substrate, were found to generate superoxide (O- 2), as determined by the reduction of added cytochrome c and by the inhibition of this reduction in the presence of superoxide dismutase.In addition to generating Of, the xanthine oxidase-treated platelets display both aggregation and evidence of the release reaction. This xanthine oxidase induced aggreagtion is not inhibited by the addition of either superoxide dismutase or cytochrome c, suggesting that it is due to either a further metabolite of O- 2, or that O- 2 itself exerts no important direct effect on platelet function under these experimental conditions. The ability of Of to modulate platelet reactions in vivo or in vitro remains in doubt, and xanthine oxidase is an unsuitable source of O- 2 in platelet studies because of its own effects on platelets.

The Effect of Barbituric Acid Derivatives on Platelet Function in Vitro and in Vivo

1973 ◽  
Vol 30 (02) ◽  
pp. 315-326
Author(s):  
J. Heinz Joist ◽  
Jean-Pierre Cazenave ◽  
J. Fraser Mustard
Keyword(s):  
Platelet Aggregation ◽  
Platelet Function ◽  
Barbituric Acid ◽  
Platelet Rich Plasma ◽  
Inhibitory Effect ◽  
Primary Response ◽  
Sodium Pentobarbital ◽  
Barbituric Acid Derivatives

SummarySodium pentobarbital (SPB) and three other barbituric acid derivatives were found to inhibit platelet function in vitro. SPB had no effect on the primary response to ADP of platelets in platelet-rich plasma (PRP) or washed platelets but inhibited secondary aggregation induced by ADP in human PRP. The drug inhibited both phases of aggregation induced by epinephrine. SPB suppressed aggregation and the release reaction induced by collagen or low concentrations of thrombin, and platelet adherence to collagen-coated glass tubes. The inhibition by SPB of platelet aggregation was readily reversible and isotopically labeled SPB did not become firmly bound to platelets. No inhibitory effect on platelet aggregation induced by ADP, collagen, or thrombin could be detected in PRP obtained from rabbits after induction of SPB-anesthesia.

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