| A steady-state mechanism can account for the properties of inositol 2,4,5-trisphosphate-stimulated Ca2+ release from permeabilized L1210 cells. | |
| | |
MedLine Citation:
|
PMID: 8382056 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
We have investigated the effects of sub-maximal Ins(2,4,5)P3 concentrations on the Ca2+ permeability of the residual undischarged Ca2+ stores in electroporated or digitonin-permeabilized L1210 cells by measuring Ca(2+)-efflux rate after addition of the ATPase inhibitor thapsigargin. Low concentrations of Ins(2,4,5)P3, causing rapid discharge of a small proportion of the releasable Ca2+, result in a substantial stimulation of Ca2+ efflux after thapsigargin addition. This indicates firstly that in the absence of thapsigargin there must have been a substantial, counterbalancing, increase in rate of Ca2+ pumping, and secondly that the increased Ca2+ permeability is more consistent with a steady state than with a quantal model of Ca2+ release. Similar increases in passive Ca2+ permeability are produced by addition of concentrations of ionomycin which produce equivalent changes in Ca2+ loading to those produced by Ins(2,4,5)P3, although the time course and initial rate of Ca2+ release are very much slower. In the presence of a Ca(2+)-buffering system, the time course of Ca2+ release by Ins(2,4,5)P3 becomes superimposable on that of ionomycin, indicating that the initial rapid phase of Ins(2,4,5)P3-stimulated Ca2+ is at least partially due to positive feedback from extravesicular Ca2+. |
| | |
Authors:
|
J W Loomis-Husselbee; A P Dawson |
Related Documents
:
|
23667566 - Tram-34, a putatively selective blocker of intermediate-conductance, calcium-activated ... 21454636 - Epstein-barr virus latent membrane protein 1 increases calcium influx through store-ope... 6877356 - Detection of intracellular ca2+ transients in sympathetic neurones using arsenazo iii. 22374086 - Ca(2+) signalling by ip(3) receptors. 20306476 - Vitamin d-mediated calcium absorption in patients with clinically stable crohn's diseas... 7751936 - Swelling-induced chloride currents in neuroblastoma cells are calcium dependent. |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
|
Title: The Biochemical journal Volume: 289 ( Pt 3) ISSN: 0264-6021 ISO Abbreviation: Biochem. J. Publication Date: 1993 Feb |
Date Detail:
|
Created Date: 1993-03-18 Completed Date: 1993-03-18 Revised Date: 2009-11-18 |
Medline Journal Info:
|
Nlm Unique ID: 2984726R Medline TA: Biochem J Country: ENGLAND |
Other Details:
|
Languages: eng Pagination: 861-6 Citation Subset: IM |
Affiliation:
|
School of Biological Sciences, University of East Anglia, Norwich, U.K. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Aniline Compounds Animals Biological Transport, Active Buffers Calcium / pharmacokinetics* Calcium-Transporting ATPases / antagonists & inhibitors, physiology* Cell Membrane Permeability Fluorometry Inositol Phosphates / pharmacology* Ionomycin / pharmacology Leukemia L1210 / metabolism* Models, Biological Terpenes / pharmacology Thapsigargin Xanthenes |
| Chemical | |
Reg. No./Substance:
|
0/Aniline Compounds; 0/Buffers; 0/Inositol Phosphates; 0/Terpenes; 0/Xanthenes; 121714-13-4/Fluo-3; 56092-81-0/Ionomycin; 67526-95-8/Thapsigargin; 7440-70-2/Calcium; 91840-07-2/inositol 2,4,5-trisphosphate; EC 3.6.1.8/Calcium-Transporting ATPases |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Inhibition of inositol 1,4,5-trisphosphate 5-phosphatase by micromolar concentrations of disulfiram ...
Next Document: Stimulation of phosphoinositide hydrolysis by muscarinic receptor activation in the rat olfactory bu...