Please use this identifier to cite or link to this item:
https://hdl.handle.net/2440/8195
Citations | ||
Scopus | Web of ScienceĀ® | Altmetric |
---|---|---|
?
|
?
|
Type: | Journal article |
Title: | Plasma membrane Ca2+ release-activated Ca2+ channels with a high selectivity for Ca2+ identified by patch-clamp recording in rat liver cells |
Author: | Rychkov, G. Brereton, H. Harland, M. Barritt, G. |
Citation: | Hepatology, 2001; 33(4):938-947 |
Publisher: | W B Saunders Co |
Issue Date: | 2001 |
ISSN: | 0270-9139 1527-3350 |
Statement of Responsibility: | Grigori Rychkov, Helen M. Brereton, M. Lyn Harland and Gregory J. Barritt |
Abstract: | Repetitive waves of increased cytoplasmic Ca2+ concentration play a central role in the process by which hormones regulate liver function. Maintenance of these Ca2+ waves requires Ca2+ inflow through store-operated Ca2+ channels. The properties and mechanism(s) of activation of these channels are not well understood. Store-operated Ca2+ channels (SOCs) in the H4-IIE rat liver cell line were studied by whole-cell patch clamping. Depletion of Ca2+ in intracellular stores by intracellular perfusion with either inositol 1,4,5-trisphosphate (InsP(3)) or thapsigargin in the presence of 10 mmol/L ethylene glycol-bis(beta-aminoethyl ether)-N,N-tetraacetic acid (EGTA), or with 10 mmol/L EGTA alone, activated an inward current that reversed at a membrane potential above +40 mV. In physiologic extracellular medium, this inward current was carried exclusively by Ca2+ and was blocked by a variety of di- and trivalent cations. In the absence of extracellular Ca2+ and Mg2+, the inward current was carried by monovalent cations. This current was 10 to 30 times larger than that observed in the presence of extracellular Ca2+, and permitted the detection of single-channel events that corresponded to a single-channel conductance of about 40 pS. Both the Ca2+ and Na+ inward currents were blocked by the calmodulin antagonist, N-(6-amino hexyl)-5-chloro-1-naphthalenesulphonamide (W7), but not by calmidazolium or calmodulin-dependent protein kinase II fragment 290-309. It is concluded that liver cells possess plasma membrane Ca2+ channels that have a high selectivity for Ca2+, are activated by a decrease in the concentration of Ca2+ in intracellular stores through a mechanism that is unlikely to involve calmodulin, and are involved in re-filling intracellular Ca2+ stores during Ca2+ signaling. |
Keywords: | Liver Cell Line Cell Membrane Animals Rats Calcium Calmodulin Calcium Channels Patch-Clamp Techniques Electric Conductivity |
Description: | The definitive version may be found at www.wiley.com |
DOI: | 10.1053/jhep.2001.23051 |
Published version: | http://www3.interscience.wiley.com/cgi-bin/abstract/106597209 |
Appears in Collections: | Aurora harvest 4 Obstetrics and Gynaecology publications Physiology 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.