Related Experiment Videos
Stretch activated ion channels in ventricular myocytes.
W Craelius1, V Chen, N el-Sherif
1Department of Cardiology, State University of New York, Brooklyn 11209.
Bioscience Reports
|October 1, 1988
Summary
This study identified stretch-activated ionic channels in rat heart cells that open with mechanical tension. These channels may help regulate cell function based on physical forces.
Area of Science:
- Cardiovascular Physiology
- Ion Channel Biophysics
- Cellular Mechanotransduction
Background:
- Ventricular myocytes are crucial for heart function.
- Membrane stretch is a physiological stimulus impacting cardiac cells.
- Understanding ion channel responses to mechanical stress is key to cardiac health.
Purpose of the Study:
- To identify and characterize ionic channels in neonatal rat ventricular myocytes activated by membrane stretch.
- To investigate the properties and gating mechanisms of these stretch-activated channels.
Main Methods:
- Utilized patch-clamp electrophysiology on isolated neonatal rat ventricular myocytes.
- Applied controlled negative pressures to induce membrane stretch and record ionic currents.
- Analyzed channel conductance, reversal potential, and ion selectivity.
Main Results:
- Identified stretch-activated ionic channels with a conductance of 120pS (in isotonic KCl).
- Observed increased channel opening frequency in response to negative pressures (1-6 cm Hg).
- Found channels do not require external Ca++ and are relatively non-selective for cations.
Conclusions:
- Stretch-activated channels in ventricular myocytes are gated by physiological tension levels.
- These channels may play a role in cellular control systems, modulating membrane conductance in response to tension or osmotic changes.
- Potential implications for understanding cardiac mechanosensation and regulation.