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Modification of the cardiac transmembrane potentials and currents by polyamines
V Kecskemeti1, K Kelemen, R Marko
1Department of Pharmacology, Semmelweis University of Medicine, Budapest, Hungary.
European Journal of Pharmacology
|October 13, 1987
Summary
Polyamines like spermine and spermidine affect cardiac action potentials and ionic currents. These compounds influence resting potential, action potential rise, and repolarization in heart tissues.
Area of Science:
- Cardiovascular Physiology
- Molecular Pharmacology
- Cellular Electrophysiology
Background:
- Polyamines are essential cations involved in various cellular processes.
- Their role in cardiac electrophysiology and ionic current modulation remains incompletely understood.
Purpose of the Study:
- To investigate the effects of spermine and spermidine on cardiac action potentials and ionic currents.
- To elucidate the mechanisms underlying polyamine-induced changes in cardiac electrophysiology.
Main Methods:
- Electrophysiological recordings (resting potential, action potential parameters, voltage clamp) in isolated guinea-pig and cat atrial and papillary muscle preparations.
- Pharmacological interventions using pindolol, atropine, and indomethacin to probe signaling pathways.
Main Results:
- Spermine enhanced resting potential, action potential Vmax, and accelerated repolarization in atria, an effect blocked by indomethacin.
- Spermidine increased resting potential, Vmax, and action potential duration in guinea pig papillary muscle and atrium, and stimulated the fast inward current.
- Neither polyamine induced Ca2+-dependent slow action potentials in depolarized atrial preparations.
Conclusions:
- Polyamines, spermine and spermidine, significantly influence cardiac membrane potential and action potential characteristics.
- Their effects appear mediated through modulation of specific ionic currents, suggesting a role in regulating cardiac electrical activity.