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Isolation of Atrial Myocytes from Adult Mice
08:34

Isolation of Atrial Myocytes from Adult Mice

Published on: July 25, 2019

Mononucleated and binucleated cardiomyocytes in left atrium and pulmonary vein have different electrical activity and

Chun-Feng Huang1, Yao-Chang Chen, Hung-I Yeh

  • 1Division of Family Medicine, Saint Mary's Hospital, Luodong, Yilan, Taiwan.

Progress in Biophysics and Molecular Biology
|October 1, 2011
PubMed

Insights

Single-nucleus cardiomyocytes in the left atrium and pulmonary veins exhibit distinct electrical properties and calcium handling compared to bi-nucleus cells. This difference in nucleus number influences cardiomyocyte arrhythmogenic activity.

Area of Science:

  • Cardiovascular Physiology
  • Cell Biology
  • Electrophysiology

Background:

  • Cardiomyocytes can be mononucleated or binucleated.
  • The electrophysiological differences between these cardiomyocyte types are not well understood.
  • Left atrium and pulmonary veins are key in atrial fibrillation initiation.

Purpose of the Study:

  • To investigate the electrical properties and calcium homeostasis in mononucleated versus binucleated cardiomyocytes from the left atrium and pulmonary veins.
  • To determine if nucleus number impacts cardiomyocyte function and arrhythmogenic potential.

Main Methods:

  • Whole-cell patch clamp electrophysiology.
  • Fluo-4 fluorescence imaging for intracellular calcium transients.
  • Immunocytostaining for ion channel densities (Kir 2.3, ryanodine receptors).

Main Results:

  • Mononucleated cardiomyocytes showed more positive resting membrane potentials than binucleated ones.
  • Mononucleated PV cardiomyocytes had faster beating rates and larger intracellular calcium transients than binucleated PV cells.
  • Mononucleated cells exhibited lower Kir 2.3 and higher ryanodine receptor densities compared to binucleated cells.

Conclusions:

  • Mononucleated cardiomyocytes in the left atrium and pulmonary veins possess unique electrophysiological characteristics.
  • These distinct properties, including altered calcium handling and ion channel expression, suggest a higher arrhythmogenic activity in mononucleated cells.
  • The number of nuclei in a cardiomyocyte may be a critical determinant of its electrical behavior and calcium regulation.

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