A modified method for isolating sinoatrial node myocytes from adult mice

Area of Science:

• Cardiology
• Molecular Biology
• Physiology

Background:

• The sinoatrial node (SAN) acts as the heart's natural pacemaker, initiating electrical activity and regulating heart rate.
• Sinoatrial node myocytes (SAMs) generate spontaneous action potentials that drive cardiac contraction.
• Accurate isolation of SAMs is essential for studying their protein expression and function.

Purpose of the Study:

• To develop a modified, stable, and reliable protocol for isolating sinoatrial node myocytes (SAMs) from mice.
• To improve upon existing methods that face challenges in judging digestion levels and maintaining system stability.

Main Methods:

• A modified protocol involving collagenase II and protease perfusion of the heart using a Langendorff apparatus.
• Subsequent dissociation of sinoatrial node myocytes (SAMs) after enzymatic digestion.
• Monitoring changes in heart appearance and droplet flow rate during perfusion to assess digestion extent.

Main Results:

• The modified perfusion method allows for easy and accurate judgment of enzymatic digestion levels, preventing incomplete or excessive digestion.
• Achieved a stable yield and high viability of sinoatrial node myocytes (SAMs).
• The optimized approach facilitates subsequent experimental analyses of SAMs.

Conclusions:

• The developed protocol offers a significant improvement for isolating sinoatrial node myocytes (SAMs) in mice.
• This method provides a reliable source of viable SAMs, supporting research into cardiac electrophysiology and function.
• The enhanced protocol is expected to advance studies on the molecular mechanisms underlying heart rate regulation.