Effects Of Extract Of Ginkgo Biloba On Action Potential And L-type Calcium Channel In Guinea Pig's Ventricular Myocytes

Objective To study the effects of extract of Ginkgo biloba (EGB) on action potential (AP) and L-type calcium channel in isolated guinea pig's ventricular myocytes.Methods AP was recorded by current-clamp mode and L-type calcium current (Ica-L ) was recorded by voltage-clamp mode using whole patch clamp technique.Results Action potential duration of repolarization 90%(APD9o) was shortened by 13% , 23% at the dilution of EGB 1:800 , 1:200, respectively. EGB decreased significantly Ica-t in a concentration-dependent manner. Peak Ica-L was reduced by 15% at the dilution of EGB 1:800 and 42% at 1:200, respectively. I-V relationship and the voltage of peak current did not changed significantly.Conclusion EGB shortens APD and decreases the ICS-L in a concentration-dependent manner, which may be one of critical basis of its antiarrhythmia.