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

Figure 5

Effect of GA on normalized steady-state inactivation curves. (a) Representative active current traces for steady-state inactivation using a three-pulse protocol with various interpulse repolarization levels (from −120 mV to 20 mV). (b) The time constant of inactivation was significantly reduced at all membrane potential values (𝑃<0.05, 𝑛=5). (c) Normalized steady-state inactivation curves before and after 5 μM GA application (𝑃<0.05, 𝑛=5). Data were expressed as mean ± SEM. Solid lines represent fits to the Boltzmann sigmoidal function. Statistical comparisons were made using a two-tailed Student’s t-test. (*𝑃<0.05,**𝑃<0.01).

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