Measuring Cardiomyocyte Contractility and Calcium Handling In Vitro

Area of Science:

• Cardiology
• Cell Physiology
• Biophysics

Background:

• In vitro studies of cardiomyocyte function are crucial for understanding heart failure.
• Assessing cardiomyocyte contractility and intracellular calcium (Ca²⁺) handling reveals physiological consequences of genetic changes and aids therapeutic target identification.

Purpose of the Study:

• To describe a modified protocol for isolating adult murine cardiomyocytes.
• To provide a detailed guide for analyzing cardiomyocyte Ca²⁺ transient and contractility data using the IonOptix system.
• To offer insights into myocardial mechanics through comprehensive analysis of Ca²⁺ handling and contractility.

Main Methods:

• A modified protocol for isolating adult cardiomyocytes from murine hearts.
• Utilizing the Myocyte Calcium and Contractility System (IonOptix) for simultaneous measurement of sarcomere movement and intracellular Ca²⁺.
• A novel cannulation technique to improve the isolation process and cardiomyocyte viability.
• Comprehensive analysis of intracellular Ca²⁺ handling, SR Ca²⁺ load, myofilament Ca²⁺ sensitivity, and cardiomyocyte contractility.

Main Results:

• The modified isolation protocol, including a novel cannulation technique, simplifies the procedure and improves the viability of isolated adult cardiomyocytes.
• The IonOptix system enables simultaneous tracing of cardiomyocyte contractility and intracellular Ca²⁺ dynamics.
• The described analysis provides a thorough assessment of myocardial function, including Ca²⁺ handling and mechanical properties.

Conclusions:

• The optimized protocol facilitates reliable isolation and analysis of cardiomyocyte function.
• This methodology offers valuable insights into the mechanisms underlying myocardial mechanics and heart failure.
• The IonOptix system serves as a powerful platform for investigating cardiomyocyte physiology and identifying therapeutic strategies.