Related Experiment Video
Updated: Jun 5, 2026

Isolation of Human Atrial Myocytes for Simultaneous Measurements of Ca2+ Transients and Membrane Currents
Published on: July 3, 2013
[Effect of cilostazol on transient outward potassium current in human atrial myocytes]
1Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
Aim:
To investigate the effect of cilostazol on transient outward potassium current (I(to1) in isolated human atrial myocytes.
Methods:
Atrial tissue samples were obtained from hearts of 15 patients ranging from 5 to 65 years of age (36.0 +/- 23.9 years). I(to1) was recorded by using the whole-cell patch clamp technique in enzymatically isolated atrial myocytes.
Results:
Cilostazol at 30 micromol/ L significantly decreased I(to1) at the test potential of +50 mV. The peak amplitude of I(to1) was decreased from (8.16 +/- 0.70) pA/pF to (4.84 +/- 0.60) pA/pF (P < 0.01). In addition, the drug inhibited the current in a concentration-dependent manner (IC50 = 13.18 +/- 2.60 micromol/L). The significantly inhibitive effect was observed from the concentration of 1 micromol/L, and the maximal effect was 51.09% +/- 3.0% at 50 micromol/L. Furthermore, voltage-dependence of activation and inactivation, and time-dependent recovery from inactivation of I(to1) were not altered by cilostazol.
Conclusion:
The results indicates that cilostazol inhibits I(to1) in human atrial myocytes.
More Related Videos
Related Concept Videos
Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers
Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers
Depolarizing Blockers: Mechanism of Action
Succinylcholine is the most commonly used depolarizing blocker. Chemically, it constitutes two molecules of acetylcholine joined together by an acetate methyl group. They act on the receptors in the same way as acetylcholine. Because succinylcholine...
Antiarrhythmic Drugs: Class IV Agents as Calcium Channel Blockers
Verapamil, a calcium channel blocker, inhibits calcium movement across myocardial cell membranes and vascular smooth muscle. This results in the dilation of coronary and...
Antiarrhythmic Drugs: Class I Agents as Sodium Channel Blockers
Class 1A Antiarrhythmic Drugs: These drugs work by moderately blocking sodium channels,...
ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias

