Please use this identifier to cite or link to this item:
https://hdl.handle.net/2440/27473
Citations | ||
Scopus | Web of Science® | Altmetric |
---|---|---|
?
|
?
|
Type: | Journal article |
Title: | Arachidonic acid inhibits the store-operated Ca2+ current in rat liver cells |
Author: | Rychkov, G. Litjens, T. Roberts, M. Barritt, G. |
Citation: | Biochemical Journal, 2005; 385(2):551-556 |
Publisher: | Portland Press |
Issue Date: | 2005 |
ISSN: | 0264-6021 1470-8728 |
Statement of Responsibility: | Grigori Y. Rychkov, Tom Litjens, Michael L. Roberts and Greg J. Barritt |
Abstract: | Vasopressin and other phospholipase-C-coupled hormones induce oscillations (waves) of [Ca2+]cyt (cytoplasmic Ca2+ concentration) in liver cells. Maintenance of these oscillations requires replenishment of Ca2+ in intracellular stores through Ca2+ inflow across the plasma membrane. While this may be achieved by SOCs (store-operated Ca2+ channels), some studies in other cell types indicate that it is dependent on AA (arachidonic acid)-activated Ca2+ channels. We studied the effects of AA on membrane conductance of rat liver cells using whole-cell patch clamping. We found no evidence that concentrations of AA in the physiological range could activate Ca2+-permeable channels in either H4IIE liver cells or rat hepatocytes. However, AA (1–10 µM) did inhibit (IC50=2.4±0.1 µM) Ca2+ inflow through SOCs (ISOC) initiated by intracellular application of Ins(1,4,5)P3 in H4IIE cells. Pre-incubation with AA did not inhibit ISOC development, but decreased maximal amplitude of the current. Iso-tetrandrine, widely used to inhibit receptor-activation of phospholipase A2, and therefore AA release, inhibited ISOC directly in H4IIE cells. It is concluded that (i) in rat liver cells, AA does not activate an AA-regulated Ca2+-permeable channel, but does inhibit SOCs, and (ii) iso-tetrandrine and tetrandrine are effective blockers of CRAC (Ca2+-release-activated Ca2+) channel-like SOCs. These results indicate that AA-activated Ca2+-permeable channels do not contribute to hormone-induced increases or oscillations in [Ca2+]cyt in liver cells. However, AA may be a physiological modulator of Ca2+ inflow in these cells. |
Keywords: | arachidonic acid Ca2+-release-activated Ca2+ channel (CRAC channel) H4IIE liver cell iso-tetrandrine patch-clamp recording store-operated Ca2+ channel |
Description: | Copyright © 2005 The Biochemical Society |
DOI: | 10.1042/BJ20041604 |
Published version: | http://dx.doi.org/10.1042/bj20041604 |
Appears in Collections: | Aurora harvest 2 Molecular and Biomedical Science publications |
Files in This Item:
There are no files associated with this item.
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.