Document Detail

Cyclooxygenase-1 and -2 of endothelial cells utilize exogenous or endogenous arachidonic acid for transcellular production of thromboxane.
MedLine Citation:
PMID:  8662657     Owner:  NLM     Status:  MEDLINE    
The presence of prostaglandin (PG) H2 in the supernatant of human umbilical vein endothelial cells (HUVEC) stimulated by thrombin restores the capacity of aspirin-treated platelets to generate thromboxane (TX) B2. Induction of cyclooxygenase-2 (Cox-2) by interleukin (IL)-1alpha or a phorbol ester increases this formation. HUVEC treated with aspirin lost their capacity to generate PGs but recovery occurred after 3- or 6-h induction of Cox-2 with phorbol ester or IL-1alpha. Enzyme activity of the newly synthesized Cox-2 in aspirin-treated cells, evaluated after immunoprecipitation, was similar to untreated cells but after 18 h of cell stimulation only 50-60% recovery of Cox-1 was observed. The use of SC58125, a selective Cox-2 inhibitor, confirmed these findings in intact cells. Cyclooxygenase activity was related to the amount of Cox proteins present in the cells, but after induction of Cox-2, contribution of the latter to PG production was 6-8-fold that of Cox-1. Aspirin-treated or untreated cells were incubated in the absence or presence of SC58125 and stimulated by thrombin, the ionophore A23187, or exogenous arachidonic acid. The production of endogenous (6-keto-PGF1alpha, PGE2, PGF2alpha) versus transcellular (TXB2) metabolites was independent of the inducer, the source of arachidonic acid and the Cox isozyme. However, in acetylsalicylic acid-treated cells, after 6-h stimulation with IL-1alpha, newly synthesized Cox-2 produced less TXB2 than 6-keto-PGF1alpha compared to untreated cells. At later times (>18 h), there was no metabolic difference between the cells. These studies suggest that in HUVEC, Cox compartmentalization occurring after short-term activation may selectively affect transcellular metabolism, but not constitutive production, of PGs.
S Karim; A Habib; S Lévy-Toledano; J Maclouf
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The Journal of biological chemistry     Volume:  271     ISSN:  0021-9258     ISO Abbreviation:  J. Biol. Chem.     Publication Date:  1996 May 
Date Detail:
Created Date:  1996-08-29     Completed Date:  1996-08-29     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  2985121R     Medline TA:  J Biol Chem     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  12042-8     Citation Subset:  IM    
U348 INSERM, Institut Fédératif de Recherche Biologie de la Circulation-Lariboisière, Hôpital Laribosière, Paris, France.
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MeSH Terms
Arachidonic Acid / metabolism*
Aspirin / pharmacology
Blood Platelets / metabolism*
Cell Communication
Cells, Cultured
Cyclooxygenase 1
Cyclooxygenase 2
Endothelium, Vascular / cytology,  metabolism*
Isoenzymes / physiology*
Membrane Proteins
Prostaglandin H2
Prostaglandin-Endoperoxide Synthases / physiology*
Prostaglandins H / biosynthesis
Thrombin / pharmacology
Thromboxanes / biosynthesis*
Reg. No./Substance:
0/Isoenzymes; 0/Membrane Proteins; 0/Prostaglandins H; 0/Thromboxanes; 42935-17-1/Prostaglandin H2; 50-78-2/Aspirin; 506-32-1/Arachidonic Acid; EC 1; EC 2; EC protein, human; EC protein, human; EC Synthases; EC

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