Inhibitory Effects of Glycyrrhetinic Acid on the Delayed Rectifier Potassium Current in Guinea Pig Ventricular Myocytes and HERG Channel

Figure 2

Effect of GA on the slow and rapid components of the delayed rectifier K⁺ current in guinea pig ventricular myocytes. (a) Representative traces of the rapid (𝐼_Kr) and slow (𝐼_Ks) components of the delayed rectifier K⁺ channel tail currents before and after treatment with 10 μM GA and 2 μM E-4031. The effects of 1, 5, and 10 μM GA and 2 μM E-4031 on 𝐼_Ks,tail (b) and 𝐼_Kr,tail (c), normalized relative to the control current (𝑛=5, 𝑃<0.05). The tail current amplitudes were differences between peak outward current and the steady state current at the end of the repolarizing voltage pulses. (*𝑃<0.05, **𝑃<0.01).

(a)

(b)

(c)