Evidence map›Paper›PMID 10457095›Full record

ArticleThe Journal of physiology1999

Relationship between transient outward K+ current and Ca2+ influx in rat cardiac myocytes of endo- and epicardial origin.

T Volk, T H Nguyen, J H Schultz, H Ehmke

Open access · greenAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in The Journal of physiology, 1999. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 29 papers.

0numbers the graph read from it
0cells of the map it votes in
29citing papers in PubMed
2.8field-weighted citation impact, top 9% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

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

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

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

29 citing papers in PubMed, 84 citations in OpenAlex.

  1. Article
  2. Article
  3. Article
  4. Phase 1 repolarization rate defines CaThe Journal of general physiology · 2019
    Article
  5. Article
  6. Transmural gradients in ion channel and auxiliary subunit expression.Progress in biophysics and molecular biology · 2016
    Review
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  15. Article
  16. Electrophysiological remodeling in heart failure.Journal of molecular and cellular cardiology · 2010
    Review
  17. Article
  18. Article
  19. 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

4 authors at 2 institutions in 1 country.

T VolkI. Physiologisches Institut der Ruprecht-Karls Universität, Im Neuenheimer Feld 326, 69120 Heidelberg, Germany. tilmann.volk@urz.uni-heidelberg.de
T H Nguyen
J H Schultz
H Ehmke
Heidelberg University · DEUniversität Hamburg · DE

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

1. The transient outward K+ current (Ito) is a major repolarizing ionic current in ventricular myocytes of several mammals. Recently it has been found that its magnitude depends on the origin of the myocyte and is regulated by a number of physiological and pathophysiological signals. 2. The relationship between the magnitude of Ito, action potential duration (APD) and Ca2+ influx (QCa) was studied in rat left ventricular myocytes of endo- and epicardial origin using whole-cell recordings and the action potential voltage-clamp method. 3. Under control conditions, in response to a depolarizing voltage step to +40 mV, Ito averaged 12.1 +/- 2.6 pA pF-1 in endocardial (n = 11) and 24.0 +/- 2.6 pA pF-1 in epicardial myocytes (n = 12; P < 0.01). APD90 (90 % repolarization) was twice as long in endocardial myocytes, whereas QCa inversely depended on the magnitude of Ito. L-type Ca2+ current density was similar in myocytes from both regions. 4. To determine the effects of controlled reductions of Ito on QCa, recordings were repeated in the presence of increasing concentrations of the Ito inhibitor 4-aminopyridine. 5. Inhibition of Ito by as little as 20 % more than doubled QCa in epicardial myocytes, whereas it had only a minor effect on QCa in myocytes of endocardial origin. Further inhibition of Ito led to a progressive increase in QCa in epicardial myocytes; at 90 % inhibition of Ito, QCa was four times larger than the control value. 6. We conclude that moderate changes in the magnitude of Ito strongly affect QCa primarily in epicardial regions. An alteration of Ito might therefore allow for a regional regulation of contractility during physiological and pathophysiological adaptations.

Indexed as

Action PotentialsAnimalsCalciumElectrophysiologyEndocardiumFemaleMyocardiumPericardiumPotassium ChannelsRatsRats, Sprague-DawleyCalciumPotassium Channels

Identifiers

PMID10457095
PMCPMC2269536
OpenAlexW2072821264

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

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.