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08:34
Isolation of Atrial Myocytes from Adult Mice
Published on: July 25, 2019
An outwardly rectifying anionic background current in atrial myocytes from the human heart
1Department of Pharmacology, Bristol Heart Institute, School of Medical Sciences, The University of Bristol, University Walk, Bristol BS8 1TD, UK.
Biochemical and Biophysical Research Communications
|June 15, 2007
Summary
A novel anionic background current (I(ANION)) was identified in human atrial cardiomyocytes. This current influences the cardiac action potential, impacting repolarization and calcium currents.
Area of Science:
- Cardiology
- Electrophysiology
- Ion Channel Physiology
Background:
- Human atrial cardiomyocytes possess a previously uncharacterized anionic background current.
- This current exhibits distinct properties compared to similar currents in other species.
Purpose of the Study:
- To characterize the novel anionic background current in human atrial cardiomyocytes.
- To investigate the functional impact of this current on the human atrial action potential.
Main Methods:
- Whole-cell patch-clamp electrophysiology with anion-selective conditions.
- Pharmacological assessment using known channel modulators and blockers.
- Computational simulation of the human atrial action potential incorporating the identified current.
Main Results:
- An outwardly rectifying anionic current (I(ANION)) was observed, with halide permeability order I- > NO3- > Cl-.
- I(ANION) was not modulated by tefluthrin, hyperosmolar solutions, or DIDS, differentiating it from volume-sensitive anion channels.
- Partial inhibition by NPPB and Gly H-101 suggests involvement of specific chloride channels.
- Simulations showed I(ANION) depresses the action potential plateau and shortens repolarization.
Conclusions:
- A novel anionic background current exists in human atrial cardiomyocytes.
- This current significantly influences the human atrial action potential profile, affecting repolarization dynamics.
- Further investigation into the specific channel(s) mediating I(ANION) is warranted.
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