title: [Effect of cilostazol on transient outward potassium current in human atrial myocytes].
abstract: OBJECTIVE
  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.
  
  
  CONCLUSIONS
  The results indicates that cilostazol inhibits I(to1) in human atrial myocytes.
authors.affiliation: Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
authors.forename: Guo-sheng
authors.initials: GS
authors.lastname: Xiao
authors.forename: Yu-hua
authors.initials: YH
authors.lastname: Liao
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D000077407:Cilostazol; D005260:Female; D006325:Heart Atria / Q000166:cytology* / Q000187:drug effects; D006801:Humans; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology*; D008875:Middle Aged; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000502:physiology*; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000502:physiology*; D013777:Tetrazoles / Q000494:pharmacology*; D055815:Young Adult
chemical_list: D015221:Potassium Channels; D013777:Tetrazoles; D000077407:Cilostazol