Document Detail


Differential effect of external calcium on the oxygenated metabolism of endogenous and exogenous arachidonic acid in platelets.
MedLine Citation:
PMID:  3927915     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The oxygenation of arachidonic acid into thromboxane B2 (TXB2), 12-hydroxy-heptadecatrienoic (HHT) and 12-hydroxy-eicosatetraenoic (12-HETE) acids has been examined in human platelets in the absence or presence of 1mM calcium. From endogenous arachidonic acid, external calcium did not affect the formation of cyclo-oxygenase products (TXB2 and HHT) but enhanced that of 12-HETE when thrombin at high concentrations was the agonist. Dose-response curves performed with thrombin and collagen revealed that increased stimulation resulted in higher ratios of 12-HETE/HHT. On the other hand external calcium did not alter significantly the synthesis of either products from exogenous arachidonic acid and the total conversion of the substrate was unchanged. We conclude that extracellular calcium may facilitate the liberation of arachidonic acid from platelet phospholipids when induced by high thrombin concentrations. The excess of arachidonic acid liberated would then be diverted towards the lipoxygenase pathway.
Authors:
B Velardo; M Lagarde
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Biochemical and biophysical research communications     Volume:  130     ISSN:  0006-291X     ISO Abbreviation:  Biochem. Biophys. Res. Commun.     Publication Date:  1985 Aug 
Date Detail:
Created Date:  1985-09-25     Completed Date:  1985-09-25     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0372516     Medline TA:  Biochem Biophys Res Commun     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1109-14     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
12-Hydroxy-5,8,10,14-eicosatetraenoic Acid
Arachidonic Acid
Arachidonic Acids / blood*
Blood Platelets / drug effects,  metabolism*
Calcium / pharmacology*
Chromatography, High Pressure Liquid
Fatty Acids, Unsaturated / biosynthesis,  blood
Humans
Hydroxyeicosatetraenoic Acids / biosynthesis,  blood
Kinetics
Oxidation-Reduction
Thromboxane B2 / biosynthesis,  blood
Chemical
Reg. No./Substance:
0/Arachidonic Acids; 0/Fatty Acids, Unsaturated; 0/Hydroxyeicosatetraenoic Acids; 15514-88-2/12-hydroxy-8,10-heptadecadienoic acid; 506-32-1/Arachidonic Acid; 54397-85-2/Thromboxane B2; 59985-28-3/12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; 7440-70-2/Calcium

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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