Evidence map›Paper›PMID 8599644›Full record

ArticleBiophysical journal1995

Highly cooperative Ca2+ elevations in response to Ins(1,4,5)P3 microperfusion through a patch-clamp pipette.

J Schrenzel, N Demaurex, M Foti, C Van Delden, J Jacquet, G Mayr, D P Lew, K H Krause

Abstract read
In one paragraph

Article in Biophysical journal, 1995. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed.

  1. Article
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors.

J SchrenzelInfectious Diseases Division, University Hospital, Geneva, Switzerland. schrenze@dminovl.hcuge.ch
N Demaurex
M Foti
C Van Delden
J Jacquet
G Mayr
D P Lew
K H Krause

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

To study the initial kinetics of Ins(1,4,5)P3-induced [Ca2+]i elevations with a high time resolution and to avoid the problem of cell-to-cell heterogeneity, we have used the combined patch-clamp/microfluorimetry technique. The mathematical description of the microperfusion of Ins(1,4,5)P3 and the subsequent Ca2+ release consists of a monoexponential decay (cytosolic Ins(1,4,5)P3 concentration) and a Hill equation (Ins(1,4,5)P3 dose-response curve). Two additional Hill equations and an integration were necessary to include a putative dependence of Ins(1,4,5)P3-induced Ca2+ release on [Ca2+]i. Best-fitting analysis assuming [Ca2+]i-independent Ca2+ release yielded Hill coefficients between 4 and 12. The high cooperativity was also observed with the poorly metabolizable analog Ins(2,4,5)P3 and was independent of extracellular [Ca2+]. Best-fitting analysis including a positive [Ca2+]i feedback suggested a cooperativity on the level of Ins(1,4,5)P3-induced channel opening (n = 2) and an enhancement of Ins(1,4,5)P3-induced Ca2+ release by [Ca2+]i. In summary, the onset kinetics of Ins(1,4,5)P3-induced [Ca2+]i elevations in single HL-60 granulocytes showed a very high cooperativity, presumably because of a cooperativity on the level of channel opening and a positive Ca2+ feedback, but not because of Ca2+ influx or Ins(1,4,5)P3 metabolism. This high cooperativity, acting in concert with negative feedback mechanisms, might play an important role in the fine-tuning of the cellular Ca2+ signal.

Indexed as

CalciumCalcium RadioisotopesCell MembraneCell Membrane PermeabilityFluorescent DyesFura-2HL-60 CellsHumansInositol 1,4,5-TrisphosphateKineticsMathematicsMicrochemistryModels, TheoreticalPatch-Clamp TechniquesPerfusionSubcellular FractionsCalciumCalcium RadioisotopesFluorescent DyesFura-2Inositol 1,4,5-Trisphosphate

Identifiers

PMID8599644
PMCPMC1236475

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.