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

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.

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

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657338 ◽

1983 ◽

Vol 49 (02) ◽

pp. 132-137 ◽

Cited By ~ 16

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.

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Endothelin B Receptor Antagonist Increases Preproendothelin-1 Transcription in Bovine Aortic Endothelial Cells and In Vivo

Journal of Cardiovascular Pharmacology ◽

10.1097/01.fjc.0000211755.54691.ba ◽

2006 ◽

Vol 47 (5) ◽

pp. 668-672 ◽

Cited By ~ 3

Author(s):

Michael Peled ◽

Aviv Shaish ◽

Liron Frishman ◽

Hofit Cohen ◽

Reshef Tal ◽

...

Keyword(s):

Endothelial Cells ◽

Receptor Antagonist ◽

Endothelin B Receptor ◽

Aortic Endothelial Cells ◽

Bovine Aortic Endothelial Cells ◽

Endothelin B ◽

Aortic Endothelial

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Immunocytochemical studies of endothelial cells in vivo. II. Chicken aortic and capillary endothelial cells exhibit different cell surface distributions of the integrin complex.

Journal of Histochemistry & Cytochemistry ◽

10.1177/36.10.2458407 ◽

1988 ◽

Vol 36 (10) ◽

pp. 1309-1317 ◽

Cited By ~ 23

Author(s):

T Fujimoto ◽

S J Singer

Keyword(s):

Endothelial Cells ◽

Monoclonal Antibodies ◽

Cell Types ◽

Frozen Sections ◽

Double Labeling ◽

Adhesion Properties ◽

Aortic Endothelial Cells ◽

Capillary Endothelial Cells ◽

Aortic Endothelial

Frozen sections of chicken tissues containing aortic and capillary endothelial cells were immunolabeled with two mouse monoclonal antibodies directed to different epitopes of the chicken integrin beta-chain. Integrin is an integral membrane protein complex that is believed to mediate a transmembrane linkage between the extracellular matrix and the actin cytoskeleton. In immunofluorescence experiments with semi-thin frozen sections, the aortic endothelial cells were labeled for integrin all around their surfaces, whereas capillary endothelial cells of heart and kidney were labeled only on their basal surfaces. At the immunofluorescence level of resolution, the distribution of integrin appeared to be correlated with that of F-actin in double-labeling experiments with NBD-phallacidin. These different distributions of integrin on the two types of endothelial cells were definitively confirmed by immunoelectron microscopic labeling with the monoclonal antibodies on ultra-thin frozen sections. These results therefore indicate that the luminal surfaces, as well as the underlying cytoskeleton of capillary endothelial cells, are significantly different in structure from those of aortic endothelial cells. These differences may reflect the vastly different hemodynamic stress to which the two types of endothelial cells are subjected, and in addition may mediate different adhesion properties of the luminal surfaces of the two cell types.

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Influence of Nicotine and Cotinine on the Expression of Plasminogen Activator Activity in Bovine Aortic Endothelial Cells

Thrombosis and Haemostasis ◽

10.1055/s-0038-1646529 ◽

1989 ◽

Vol 61 (01) ◽

pp. 070-076 ◽

Cited By ~ 11

Author(s):

Be-Sheng Kuo ◽

Maciej Dryjski ◽

Thorir D Bjornsson

Keyword(s):

Endothelial Cells ◽

Plasminogen Activator ◽

Plasminogen Activator Inhibitor ◽

Dependent Manner ◽

Aortic Endothelial Cells ◽

Bovine Aortic Endothelial Cells ◽

Fibrin Plate ◽

Sds Page ◽

Aortic Endothelial

SummaryThe effects of nicotine and its major metabolite, cotinine, were evaluated on the secretion of plasminogen activator (PA) and plasminogen activator inhibitor (PAI) in cultured bovine aortic endothelial cells. Both compounds increased PA secretion, determined by 125I-fibrin plate assay, in a time- and dose-dependent manner. Maximum effects after 24 hr incubation were observed for nicotine at 10-8 M and for cotinine at 10-7 M, which corresponded to about 2.6-fold increases over control for both compounds. The pharmacological PA stimulation required both RNA and protein syntheses, as evidenced by inhibition by acfinomycin D and cycloheximide. Both control and treated cells produced multiple forms of PA, as evaluated by SDS-PAGE zymography, and a single form of PAI, as evidenced by reverse fibrin autography. Although activities of all species of PA were enhanced by nicotine and cotinine, these compounds had no significant effects on the release of PAI. These results thus suggest that nicotine and cotinine may have fibrinolytic activity in vivo.

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

AJP Cell Physiology ◽

10.1152/ajpcell.1996.271.2.c555 ◽

1996 ◽

Vol 271 (2) ◽

pp. C555-C562 ◽

Cited By ~ 16

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.

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