Effect of membrane potential on cytosolic calcium of bovine aortic endothelial cells

1989 ◽  
Vol 257 (3) ◽  
pp. H778-H784 ◽  
Author(s):  
W. P. Schilling
Keyword(s):  
Endothelial Cells ◽  
Membrane Potential ◽  
Cytosolic Calcium ◽  
Membrane Depolarization ◽  
K Channel ◽  
Membrane Hyperpolarization ◽  
Aortic Endothelial Cells ◽  
Bovine Aortic Endothelial Cells ◽  
K Concentration ◽  
Aortic Endothelial

The effect of bradykinin on membrane potential of cultured bovine aortic endothelial cells (BAECs) was estimated by measuring the uptake of the lipophilic cation, tetra[3H]phenylphosphonium ([3H]TPP+). Uptake of [3H]TPP+ was found to be 1) a function of extracellular K+ concentration, 2) sensitive to valinomycin, and 3) decreased by the K+ channel inhibitor, Ba2+, suggesting that the uptake of [3H]TPP+ responds to changes in membrane potential of the BAEC. Bradykinin (50 nM) produced an increase in [3H]TPP+ uptake in low K+ buffer consistent with a bradykinin-induced membrane hyperpolarization. The effect of membrane depolarization with high K+ buffer on the bradykinin-stimulated changes in cytosolic Ca2+ was determined using the fluorescent Ca2+ indicator, fura-2. The results of these experiments demonstrated that both basal cytosolic Ca2+ and bradykinin-stimulated release of Ca2+ from internal stores were not affected by membrane depolarization. However, bradykinin-stimulated influx of Ca2+ from the extracellular space decreased with membrane depolarization in a manner consistent with the movement of Ca2+ through a channel.

scholarly journals A delayed and sustained rise of cytosolic calcium is elicited by oxidized LDL in cultured bovine aortic endothelial cells

FEBS Letters ◽  
1992 ◽  
Vol 299 (1) ◽  
pp. 60-65 ◽  
Author(s):  
Anne Nègre-Salvayre ◽  
Guylène Fitoussi ◽  
Valérie Réaud ◽  
Marie-Thérèse Pieraggi ◽  
Jean-Claude Thiers ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Oxidized Ldl ◽  
Cytosolic Calcium ◽  
Aortic Endothelial Cells ◽  
Bovine Aortic Endothelial Cells ◽  
Aortic Endothelial

Fura-2 fluorescence is localized to mitochondria in endothelial cells

1987 ◽  
Vol 253 (5) ◽  
pp. C744-C747 ◽  
Author(s):  
S. F. Steinberg ◽  
J. P. Bilezikian ◽  
Q. Al-Awqati
Keyword(s):  
Endothelial Cells ◽  
Calcium Ion ◽  
Cytosolic Calcium ◽  
Ion Concentration ◽  
Homogeneous Distribution ◽  
Aortic Endothelial Cells ◽  
Fura 2 ◽  
Bovine Aortic Endothelial Cells ◽  
Calcium Ion Concentration ◽  
Aortic Endothelial

The new, highly fluorescent, calcium-sensitive dye, fura-2, can be loaded nondisruptively into intact cells by means of its permeant ester and used to measure the free calcium ion concentration in individual cells. For fura-2 to signal cytosolic calcium, it must be distributed homogeneously and exclusively throughout the cytoplasmic space. However, microscopic examination of bovine aortic endothelial cells loaded with fura-2 by exposure to its permeant ester reveals fluorescence associated with discrete intracellular structures rather than the homogeneous distribution expected for a cytosolic stain. Simultaneous labeling of bovine aortic endothelial cells with fura-2 and rhodamine 123 (a mitochondrial fluorescent vital stain) identifies these structures as mitochondria. Subcellular dye localizations are not observed when the cells are loaded with other putative cytosolic stains that gain access to the cytosol by means of a membrane permeant ester. Both carboxyfluorescein and indo-1 (another member of the family of second generation calcium indicators) stain the cytoplasm diffusely. It is suggested that fura-2 fluorescence accumulates in certain cells in association with mitochondria. It is important to assess the intracellular distribution of fura-2 when this indicator is used to measure the free cytosolic calcium ion concentration.

Characterization of ATP-sensitive potassium channels in freshly dissociated rabbit aortic endothelial cells

1997 ◽  
Vol 272 (5) ◽  
pp. H2507-H2511 ◽  
Author(s):  
C. Katnik ◽  
D. J. Adams
Keyword(s):  
Endothelial Cells ◽  
Single Channel ◽  
Muscle Tone ◽  
Cell Metabolism ◽  
Katp Channels ◽  
K Channel ◽  
Membrane Hyperpolarization ◽  
Aortic Endothelial Cells ◽  
Intracellular Atp ◽  
Aortic Endothelial

ATP-sensitive potassium (KATP) channels represent a class of K+ channel regulated by intracellular ATP and serve to transduce changes in cell metabolism into changes in membrane potential. The presence of an KATP conductance has recently been demonstrated in freshly dissociated endothelial cells from rabbit arteries. In the present study, the single-channel activity underlying the KATP conductance in rabbit aortic endothelial cells was examined. Unitary currents were evoked in response to lowering intracellular ATP concentration or application of the K(+)-channel activator levcromakalim and were inhibited by the sulfonylurea drug glibenclamide. Exposure of the cytoplasmic face of an inside-out membrane patch to a solution containing 0.1 mM ATP produced single-channel events with unitary conductances of approximately 150 and approximately 25 pS that were inhibited by either 6 mM ATP or 10 microM glibenclamide. A small conductance channel was also activated in cell-attached patches by bath-applied levcromakalim (25 microM). Activation of endothelial cell KATP channels, and subsequent membrane hyperpolarization, may contribute to endothelium-dependent regulation of vascular smooth muscle tone in response to changes in levels of intracellular metabolites.

Membrane depolarization and NADPH oxidase activation in aortic endothelium during ischemia reflect altered mechanotransduction

2005 ◽  
Vol 288 (1) ◽  
pp. H336-H343 ◽  
Author(s):  
Ikuo Matsuzaki ◽  
Shampa Chatterjee ◽  
Kris DeBolt ◽  
Yefim Manevich ◽  
Qunwei Zhang ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Plasma Membrane ◽  
Membrane Potential ◽  
Nadph Oxidase ◽  
Membrane Depolarization ◽  
Ros Generation ◽  
Similar Response ◽  
Aortic Endothelial Cells ◽  
Aortic Endothelium ◽  
Aortic Endothelial

We previously showed that “ischemia” (abrupt cessation of flow) leads to rapid membrane depolarization and increased generation of reactive oxygen species (ROS) in lung microvascular endothelial cells. This response is not associated with anoxia but, rather, reflects loss of normal shear stress. This study evaluated whether a similar response occurs in aortic endothelium. Plasma membrane potential and production of ROS were determined by fluorescence microscopy and cytochrome c reduction in flow-adapted rat or mouse aorta or monolayer cultures of rat aortic endothelial cells. Within 30 s after flow cessation, endothelial cells that had been flow adapted showed plasma membrane depolarization that was inhibited by pretreatment with cromakalim, an ATP-sensitive K+ (KATP) channel agonist. Flow cessation also led to ROS generation, which was inhibited by cromakalim and the flavoprotein inhibitor diphenyleneiodonium. Aortic endothelium from mice with “knockout” of the KATP channel (KIR6.2) showed a markedly attenuated change in membrane potential and ROS generation with flow cessation. In aortic endothelium from mice with knockout of NADPH oxidase (gp91phox), membrane depolarization was similar to that in wild-type mice but ROS generation was absent. Thus rat and mouse aortic endothelial cells respond to abrupt flow cessation by KATP channel-mediated membrane depolarization followed by NADPH oxidase-mediated ROS generation, possibly representing a cell-signaling response to altered mechanotransduction.

scholarly journals Bradykinin-induced increases in cytosolic calcium and ionic currents in cultured bovine aortic endothelial cells.

1987 ◽  
Vol 61 (5) ◽  
pp. 632-640 ◽  
Author(s):  
M Colden-Stanfield ◽  
W P Schilling ◽  
A K Ritchie ◽  
S G Eskin ◽  
L T Navarro ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Ionic Currents ◽  
Cytosolic Calcium ◽  
Aortic Endothelial Cells ◽  
Bovine Aortic Endothelial Cells ◽  
Aortic Endothelial
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