Spatial and temporal characteristics of Ca²⁺ signaling in endothelial cells of intact rat tail artery

DOI

10.1016/j.artres.2013.03.002How to use a DOI?

Keywords

Spatial; Temporal; Calcium signaling; Endothelium; Carbachol; Culture

Abstract

Very few studies have described briefly the spatial and temporal characteristics of Ca²⁺ signaling using ATP, bradykinin, histamine and thrombin in cultured endothelium. However so far, the spatial and temporal characteristics in intact endothelium have not been elucidated.

The aim of this work was to increase the understanding of characteristics of Ca²⁺ signaling in endothelial cells using real time confocal imaging of Fluo-4 loaded intact rat tail arteries. Of all the three agonist used i.e. histamine, bradykinin and carbachol; only CCh produced strong dose dependent stimulant action on the endothelial cells of intact rat tail artery. Local endothelial heterogeneity was observed in fresh intact cells in response to the three agonist used which was absent upon culture.

In agreement with the previous studies, each of the three agonists produced complex Ca²⁺ signaling consisting of initial fast followed by sustained component with Ca²⁺ oscillations superimposing it. The data supports the following conclusions: (i) Ca²⁺ puffs were evoked in 18% and 14% of cells by low concentrations of CCh (0.1 μM and 1 μM), respectively. The average diameter and width of Ca²⁺ puffs initiation sites was 1.9 ± 0.4 μm, 1.6 ± 0.1 μm, respectively. Length varied between 2 and 6 μm (n = 25 vessels). (ii) ECs responding with Ca²⁺ waves and oscillations were dependent on concentration of CCh: 0.1 μM (20%), 1 μM (65%) and 10 μM (99%). Speed of wave propagation and frequency of Ca²⁺ oscillations varied among different cells even at the same agonist concentration. (iii) Ca²⁺ waves were regenerative; initiated by one or both ends of the cell and propagated across the cell at a speed of 14–44 μm/s (iv) With increasing concentrations of CCh (0.1–10 μM), the frequency of Ca²⁺ oscillations ranged from 0.02 to 0.3 Hz with optimal frequency being about 0.2 ± 0.02 Hz (n = 15 vessels). In conclusions, this data shows the morphology, heterogeneity and detailed characteristics of Ca²⁺ signal in intact endothelial cells.

Copyright

© 2013 Association for Research into Arterial Structure and Physiology. Published by Elsevier B.V. All rights reserved.

Open Access

This is an open access article distributed under the CC BY-NC license.

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TY  - JOUR
AU  - Sadaf Mumtaz
PY  - 2013
DA  - 2013/03/28
TI  - Spatial and temporal characteristics of Ca2+ signaling in endothelial cells of intact rat tail artery
JO  - Artery Research
SP  - 84
EP  - 92
VL  - 7
IS  - 2
SN  - 1876-4401
UR  - https://doi.org/10.1016/j.artres.2013.03.002
DO  - 10.1016/j.artres.2013.03.002
ID  - Mumtaz2013
ER  -