Effect of cilostazol on transient outward potassium current in human atrial myocytes / 中国应用生理学杂志

ABSTRACT

<p><b>AIM</b>To investigate the effect of cilostazol on transient outward potassium current (I(to1) in isolated human atrial myocytes.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>The results indicates that cilostazol inhibits I(to1) in human atrial myocytes.</p>