ArticleHeart rhythm2012
Profile of L-type Ca(2+) current and Na(+)/Ca(2+) exchange current during cardiac action potential in ventricular myocytes.
Article in Heart rhythm, 2012. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 23 papers.
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.
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.
Who cites it
23 citing papers in PubMed.
- Electrophysiological tolerance: a new concept for understanding the electrical stability of the heart.Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology · 2024Review
- Local Control Model of a Human Ventricular Myocyte: An Exploration of Frequency-Dependent Changes and Calcium Sparks.Biomolecules · 2023Article
- Electrophysiological heterogeneity in large populations of rabbit ventricular cardiomyocytes.Cardiovascular research · 2022Article
- Antiarrhythmic and Inotropic Effects of Selective NaInternational journal of molecular sciences · 2022Review
- Late sodium current and calcium homeostasis in arrhythmogenesis.Channels (Austin, Tex.) · 2021Review
- Electrophysiological Effects of the Transient Receptor Potential Melastatin 4 Channel Inhibitor (4-Chloro-2-(2-chlorophenoxy)acetamido) Benzoic Acid (CBA) in Canine Left Ventricular Cardiomyocytes.International journal of molecular sciences · 2021Article
- Canine Myocytes Represent a Good Model for Human Ventricular Cells Regarding Their Electrophysiological Properties.Pharmaceuticals (Basel, Switzerland) · 2021Review
- Late Sodium Current Inhibitors as Potential Antiarrhythmic Agents.Frontiers in pharmacology · 2020Review
- How CaThe Journal of general physiology · 2019Article
- Enhanced Depolarization Drive in Failing Rabbit Ventricular Myocytes: Calcium-Dependent and β-Adrenergic Effects on Late Sodium, L-Type Calcium, and Sodium-Calcium Exchange Currents.Circulation. Arrhythmia and electrophysiology · 2019Article
- Nerol Attenuates Ouabain-Induced Arrhythmias.Evidence-based complementary and alternative medicine : eCAM · 2019Article
- Altered Repolarization Reserve in Failing Rabbit Ventricular Myocytes: Calcium and β-Adrenergic Effects on Delayed- and Inward-Rectifier Potassium Currents.Circulation. Arrhythmia and electrophysiology · 2018Article
- Low extracellular potassium prolongs repolarization and evokes early afterdepolarization in human induced pluripotent stem cell-derived cardiomyocytes.Biology open · 2017Article
- Local Field Fluorescence Microscopy: Imaging Cellular Signals in Intact Hearts.Journal of visualized experiments : JoVE · 2017Article
- Electrophysiological Determination of Submembrane Na(+) Concentration in Cardiac Myocytes.Biophysical journal · 2016Article
- Arrhythmogenesis in Timothy Syndrome is associated with defects in Ca(2+)-dependent inactivation.Nature communications · 2016Article
- Intact Heart Loose Patch Photolysis Reveals Ionic Current Kinetics During Ventricular Action Potentials.Circulation research · 2016Article
- Article
- Voltage and calcium dynamics both underlie cellular alternans in cardiac myocytes.Biophysical journal · 2014Article
- p21-Activated kinase1 (Pak1) is a negative regulator of NADPH-oxidase 2 in ventricular myocytes.Journal of molecular and cellular cardiology · 2014Article
Corrections and comments
- Commented on byChasing calcium.2012
Authors and funding
5 authors.
Funding
Abstract
objectiveThe L-type Ca(2+) current (I(Ca,L)) and the Na(+)/Ca(2+) exchange current (I(NCX)) are major inward currents that shape the cardiac action potential (AP). Previously, the profile of these currents during the AP was determined from voltage-clamp experiments that used Ca(2+) buffer. In this study, we aimed to obtain direct experimental measurement of these currents during cardiac AP with Ca(2+) cycling.
methodA newly developed AP-clamp sequential dissection method was used to record ionic currents in guinea pig ventricular myocytes under a triad of conditions: using the cell's own AP as the voltage command, using internal and external solutions that mimic the cell's ionic composition, and, importantly, not using any exogenous Ca(2+) buffer.
resultsThe nifedipine-sensitive current (I(NIFE)), which is composed of I(Ca,L) and I(NCX), revealed hitherto unreported features during the AP with Ca(2+) cycling in the cell. We identified 2 peaks in the current profile followed by a long residual current extending beyond the AP, coinciding with a residual depolarization. The second peak and the residual current become apparent only when Ca(2+) is not buffered. Pharmacological dissection of I(NIFE) by using SEA0400 shows that I(Ca,L) is dominant during phases 1 and 2 whereas I(NCX) contributes significantly to the inward current during phases 3 and 4 of the AP.
conclusionThese data provide the first direct experimental visualization of I(Ca,L) and I(NCX) during cardiac the AP and Ca(2+) cycle. The residual current reported here can serve as a potential substrate for afterdepolarizations when increased under pathologic conditions.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
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.