scholarly journals Ca2+ influx does more than provide releasable Ca2+ to maintain repetitive spiking in human umbilical vein endothelial cells

1996 ◽  
Vol 320 (2) ◽  
pp. 505-517 ◽  
Author(s):  
Anthony J. MORGAN ◽  
Ron JACOB
Keyword(s):  
Endothelial Cells ◽  
Umbilical Vein ◽  
Inositol Trisphosphate ◽  
Free Medium ◽  
Bivalent Cation ◽  
Human Umbilical Vein ◽  
Fura 2 ◽  
Umbilical Vein Endothelial Cells ◽  
Small Subpopulation

We investigated why oscillations of intracellular Ca2+ concentrations ([Ca2+]i) in endothelial cells challenged by submaximal histamine run down in Ca2+-free medium despite stores retaining most of their Ca2+. One explanation is that only a small subpopulation of the Ca2+ stores oscillate and are completely emptied of Ca2+. To investigate if influx refills an empty store subpopulation, we differentiated between cations entering the cell and those released from internal stores by using extracellular Sr2+ as a Ca2+ surrogate; we distinguished between [Sr2+]i and [Ca2+]i by using the larger effect of Sr2+ on fura 2 fluorescence at 360 nm (F360). Ca2+ was still available for release when oscillations had run down since oscillations promptly reappeared on addition of Sr2+o and these were predominantly of Ca2+ (indicated by F360 changes). Also, totally depleting Ca2+ stores inhibited Sr2+-induced oscillations, suggesting that Sr2+ entry leads to Ca2+ release. In contrast, Ba2+o was unable to stimulate oscillations. Finally, oscillations generated by photolytic release of inositol trisphosphate (IP3) analogues were similarly sensitive to extracellular Ca2+ and Sr2+. We conclude that stores (or a subpopulation) are not completely depleted of Ca2+ when oscillations run down in Ca2+-free medium. Bivalent cation entry therefore maintains sensitivity to IP3, possibly by maintaining luminal bivalent cation levels.

scholarly journals Evidence that agonists stimulate bivalent-cation influx into human endothelial cells

1988 ◽  
Vol 255 (1) ◽  
pp. 179-184 ◽  
Author(s):  
T J Hallam ◽  
R Jacob ◽  
J E Merritt
Keyword(s):  
Endothelial Cells ◽  
Plasma Membrane ◽  
Umbilical Vein ◽  
Free Calcium ◽  
Human Endothelial Cells ◽  
Bivalent Cation ◽  
Human Umbilical Vein ◽  
Fura 2 ◽  
Bivalent Cations ◽  
Umbilical Vein Endothelial Cells

Human umbilical-vein endothelial cells stimulated with thrombin or histamine show an increase in [Ca2+]i (cytoplasmic free calcium concn.) that is maintained well above the basal pre-stimulated value as long as agonist and a source of extracellular Ca2+ are present. These results provide circumstantial evidence that agonists stimulate influx of Ca2+ across the plasma membrane and into the cytoplasm. Here, we have used Mn2+ as the extracellular bivalent cation which can bind to the fluorescent Ca2+ indicator fura-2 to quench its fluorescence completely. Human umbilical-vein endothelial cells were loaded with fura-2 and, in the presence of extracellular Mn2+, thrombin and histamine were shown to cause quenching of the intracellular dye. This result demonstrates conclusively that agonists can stimulate the influx of bivalent cations. Stimulated discharge of Ca2+ from intracellular stores and influx of Mn2+ were temporally resolved in the same cells to show that release of Ca2+ from intracellular stores clearly precedes influx. Influx of Mn2+ was also demonstrated when extracellular Mn2+ was added after agonist at a time when [Ca2+]i had fallen back to the basal value, showing that influx is not dependent on elevated [Ca2+]i.

The proliferation of human umbilical vein endothelial cells in serum-free medium

1983 ◽  
Vol 31 (4) ◽  
pp. 623-634 ◽  
Author(s):  
Philip G. de Groot ◽  
Charles Willems ◽  
Mervin D. Gonsalves ◽  
Willem G. van Aken ◽  
Jan A. van Mourik
Keyword(s):  
Endothelial Cells ◽  
Umbilical Vein ◽  
Serum Free Medium ◽  
Free Medium ◽  
Serum Free ◽  
Human Umbilical Vein ◽  
Umbilical Vein Endothelial Cells

Studies of the Factor Xa-Dependent Inhibitor of Factor VIIa/Tissue Factor (Extrinsic Pathway Inhibitor) from Cell Supernates of Cultured Human Umbilical Vein Endothelial Cells

1989 ◽  
Vol 61 (01) ◽  
pp. 101-105 ◽  
Author(s):  
Bonnie J Warn-Cramer ◽  
Fanny E Almus ◽  
Samuel I Rapaport
Keyword(s):  
Molecular Weight ◽  
Endothelial Cells ◽  
Tissue Factor ◽  
Phorbol Ester ◽  
Umbilical Vein ◽  
Primary Cultures ◽  
Factor Xa ◽  
Extrinsic Pathway ◽  
Human Umbilical Vein ◽  
Umbilical Vein Endothelial Cells

SummaryCultured human umbilical vein endothelial cells (HUVEC) have been reported to produce extrinsic pathway inhibitor (EPI), the factor Xa-dependent inhibitor of factor VHa/tissue factor (TF). We examined the release of this inhibitor from HUVEC as a function of their growth state and in response to the induction of endothelial cell TF activity. HUVEC constitutively produced significant amounts of EPI at all stages of their growth in culture including the post-confluent state. Rate of release varied over a 3-fold range for primary cultures from 12 different batches of pooled umbilical cord cells. Constitutive EPI release was unaltered during a 6 hour period of induction of TF activity with thrombin or phorbol ester but slowed during longer incubation of the cells with phorbol ester. Whereas plasma contains two molecular weight forms of EPI, only the higher of these two molecular weight forms was demonstrable by Western analysis of HUVEC supernatants with 125I-factor Xa as the ligand.

Partial Characterization of a Fibrinolytic Inhibitor Produced by Cultured Endothelial Cells Derived from Human Umbilical Vein

1982 ◽  
Vol 47 (02) ◽  
pp. 128-131 ◽  
Author(s):  
F Esnard ◽  
E Dupuy ◽  
A M Dosne ◽  
E Bodevin
Keyword(s):  
Endothelial Cells ◽  
Primary Culture ◽  
Ammonium Sulphate ◽  
Concanavalin A ◽  
Umbilical Vein ◽  
Human Umbilical Vein ◽  
Preliminary Characterization ◽  
Umbilical Vein Endothelial Cells ◽  
Ammonium Sulphate Saturation

SummaryA preliminary characterization of a fibrinolytic inhibitor released by human umbilical vein endothelial cells in primary culture is reported. This molecule of Mr comprised between 2 × 105 and 106 and of μ2 mobility precipitates at 43% ammonium sulphate saturation and is totally adsorbed on Concanavalin A Sepharose 4 B. A possible relationship with a macroglobulins is discussed.

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