Dual regulation of PLA2 and PGI2 production by G proteins in bovine aortic endothelial cells

1996 ◽  
Vol 271 (2) ◽  
pp. C555-C562 ◽  
Author(s):  
M. Rosenstock ◽  
A. Danon ◽  
G. Rimon
Keyword(s):  
Endothelial Cells ◽  
G Proteins ◽  
Specific Inhibitor ◽  
Inhibitory Effect ◽  
Aortic Endothelial Cells ◽  
Biphasic Pattern ◽  
Bovine Aortic Endothelial Cells ◽  
Phenylisopropyl Adenosine ◽  
Stimulation Of ◽  
Aortic Endothelial

NaF, a nonselective activator of heterotrimeric guanine nucleotide-binding proteins (G proteins), increased the release of arachidonic acid (AA) and prostacyclin (PGI2) production in bovine aortic endothelial cells (BAEC) at low concentrations (40-60 mM). On the other hand, higher concentrations (100 mM) inhibited phospholipase A2 (PLA2) compared with the basal activity. Intracellular Ca2+ levels did not rise after treatment with stimulatory concentrations of NaF, and, moreover, neither neomycin nor Ca(2+)-free medium affected the biphasic pattern of PGI2 synthesis in response to NaF. CGP-43187, an inhibitor of the 14-kDa secretory PLA2, did not affect NaF-induced AA release. However, AACOCF3, a specific inhibitor of the cytosolic 85-kDa PLA2 (cPLA2), abrogated AA release and PGI2 production in response to 60 mM NaF. A biphasic pattern of PGI2 production was also obtained with the guanosine 5'-triphosphate analogues guanosine 5'-O-(3-thiotriphosphate) and guanylylimidodiphosphate in permeabilized BAEC. Pretreatment of the cells with guanosine 5'-O-(2-thiodiphosphate) suppressed the inhibition and the stimulation of AA release induced by guanylylimidodiphosphate. In addition, phenylisopropyl adenosine inhibited the release of AA and PGI2, whereas ATP and bradykinin increased PGI2. Pertussis toxin not only inhibited ATP- and bradykinin-stimulated PGI2 release, it also reversed the inhibitory effect of phenylisopropyl adenosine, resulting in a significant stimulation. These findings strongly suggest that, in BAEC, cPLA2 is coupled with more than one G protein that are involved in inhibition and stimulation of cPLA2 activity.

Effects of Dipyrone on Prostaglandin Production by Human Platelets and Cultured Bovine Aortic Endothelial Cells

1983 ◽  
Vol 49 (02) ◽  
pp. 132-137 ◽  
Author(s):  
A Eldor ◽  
G Polliack ◽  
I Vlodavsky ◽  
M Levy
Keyword(s):  
Endothelial Cells ◽  
Arachidonic Acid ◽  
Competitive Inhibition ◽  
Inhibitory Effect ◽  
Human Platelets ◽  
Ionophore A23187 ◽  
Aortic Endothelial Cells ◽  
Bovine Aortic Endothelial Cells ◽  
Aortic Endothelial

SummaryDipyrone and its metabolites 4-methylaminoantipyrine, 4-aminoantipyrine, 4-acetylaminoantipyrine and 4-formylaminoan- tipyrine inhibited the formation of thromboxane A2 (TXA2) during in vitro platelet aggregation induced by ADP, epinephrine, collagen, ionophore A23187 and arachidonic acid. Inhibition occurred after a short incubation (30–40 sec) and depended on the concentration of the drug or its metabolites and the aggregating agents. The minimal inhibitory concentration of dipyrone needed to completely block aggregation varied between individual donors, and related directly to the inherent capacity of their platelets to synthesize TXA2.Incubation of dipyrone with cultured bovine aortic endothelial cells resulted in a time and dose dependent inhibition of the release of prostacyclin (PGI2) into the culture medium. However, inhibition was abolished when the drug was removed from the culture, or when the cells were stimulated to produce PGI2 with either arachidonic acid or ionophore A23187.These results indicate that dipyrone exerts its inhibitory effect on prostaglandins synthesis by platelets or endothelial cells through a competitive inhibition of the cyclooxygenase system.

scholarly journals Urea transporters are distributed in endothelial cells and mediate inhibition of l-arginine transport

2002 ◽  
Vol 283 (3) ◽  
pp. F578-F582 ◽  
Author(s):  
Laszlo Wagner ◽  
Janet D. Klein ◽  
Jeff M. Sands ◽  
Chris Baylis
Keyword(s):  
Endothelial Cells ◽  
Cell Types ◽  
Inhibitory Effect ◽  
Rat Aorta ◽  
Wide Distribution ◽  
Aortic Endothelial Cells ◽  
Bovine Aortic Endothelial Cells ◽  
Elevated Blood Urea Nitrogen ◽  
Aortic Endothelial

Our laboratory previously reported that uremic levels of urea inhibitl-arginine (l-Arg) transport into endothelial cells. The present study further investigated this effect. We measuredl-Arg transport in cultured bovine aortic endothelial cells with normal or high urea (25 mM). The urea transport inhibitor phloretin abolished the inhibitory effect of urea on l-Arg transport, suggesting a role for urea transporters (UTs). We screened bovine aortic endothelial cells and several other endothelial cell types for the presence of UTs by using Western blot analysis. UT-B was present in all endothelial cells, irrespective of species or location of derivation, whereas UT-A distribution was variable and sparse. UT-B was also abundant in rat aorta, mesenteric blood vessels, and spinotrapezius muscle, whereas UT-A distribution was, again, variable and sparse. Chronic elevation of urea had variable, inconsistent effects on UT abundance. This study showed that urea must enter endothelial cells, probably by UT-B, to inhibit l-Arg transport. In view of the wide distribution of UT-B in rat vasculature, elevated blood urea nitrogen may lead to endothelial l-Arg deficiency in vivo.

The Dexamethasone-Induced Inhibitor of Plasminogen Activator in Hepatoma Cells Is Antigenically-Related to an Inhibitor Produced by Bovine Aortic Endothelial Cells

1986 ◽  
Vol 55 (01) ◽  
pp. 008-011 ◽  
Author(s):  
David J Loskutoff ◽  
Karen Roegner ◽  
Larry A Erickson ◽  
Raymond R Schleef ◽  
Anna Huttenlocher ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Plasminogen Activator ◽  
Specific Inhibitor ◽  
Hepatoma Cells ◽  
Biochemical Properties ◽  
Aortic Endothelial Cells ◽  
Bovine Aortic Endothelial Cells ◽  
Immunological Relationship ◽  
Relationship Of ◽  
Aortic Endothelial

SummaryGlucocorticoids decrease plasminogen activator (PA) activity in HTC rat hepatoma cells by inducing a specific inhibitor of PA activity (PAI). This inhibitor is similar in several biochemical properties to the PAI purified from bovine aortic endothelial cells (BAEs). We have used reverse fibrin autography and antiserum against BAE PAI to establish more fully the biochemical and immunological relationship of these inhibitors. Both inhibitors migrated with an apparent Mr of approximately 50,000, and the activity of both PAIs was stimulated by treatment with SDS suggesting that each of these molecules exists in both an active and a latent form. Antiserum to the BAE PAI immunoprecipi-tated all of the HTC PAI demonstrable by reverse fibrin autography. Finally, using this antiserum in a functional immunoassay, we have demonstrated that dexamethasone increases both active and latent PAI made by HTC cells. These results, indicate that HTC PAI and BAE PAI are antigenically as well as biochemically related molecules.

scholarly journals Stimulation of In Vitro Angiogenesis by Tetrahydrobiopterin in Bovine Aortic Endothelial Cells

1999 ◽  
Vol 80 (2) ◽  
pp. 177-180 ◽  
Author(s):  
Shunichi Shimizu ◽  
Masako Yasuda ◽  
Masakazu Ishii ◽  
Tsutomu Nagai ◽  
Yuji Kiuchi ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Aortic Endothelial Cells ◽  
Bovine Aortic Endothelial Cells ◽  
In Vitro Angiogenesis ◽  
Stimulation Of ◽  
Aortic Endothelial
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