Effects of changrolin on potassium currents in guinea pig and rabbit single heart cells.
OBJECTIVE
To elucidate whether or not changrolin (CRL) modifies the potassium currents (ITO, IK, and IKl) in myocardial cells.


METHODS
A tight seal whole-cell patch-clamp technique was used to record ITO, IK, and IKl in single cells isolated from guinea pig and rabbit hearts.


RESULTS
At a clinically relevant concentration, CRL 50 mumol.L-1 inhibited the transient outward current (ITO) by 17.7% +/- 2.4% (n = 8) in rabbit atrial cells. The voltage-dependence of steady-state inactivation of ITO was not affected by CRL. This concentration of CRL did not influence the time-independent inward rectifier or the delayed rectifier K+ currents (IKl and IK, respectively) in rabbit and guinea pig ventricular cells.


CONCLUSIONS
CRL inhibited ITO, but not IK nor IKl.
Department of Physiology, College of Medicine, Xiamen University, Xiamen 361005, China.
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D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D002469:Cell Separation; D006168:Guinea Pigs; D009206:Myocardium / Q000166:cytology*; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000187:drug effects*; D011799:Quinazolines / Q000494:pharmacology*; D011817:Rabbits
D000889:Anti-Arrhythmia Agents; D015221:Potassium Channels; D011799:Quinazolines; C022128:changrolin