Inhibitory Effects of Glycyrrhetinic Acid on the Delayed Rectifier Potassium Current in Guinea Pig Ventricular Myocytes and HERG Channel
Figure 3
Current-voltage relationship for HERG channels and blockade by GA. (a) HERG currents are illustrated under control conditions and in the presence of 5 μM GA recorded using the pulse protocol. (b) Voltage-dependent activation curves for the control and following GA exposure. Tail currents under control conditions and in the presence of 5 μM GA were normalized and fitted to the Boltzmann sigmoidal function. There were no significant differences in half-activation voltage () of 5 μM compared with the control (, ). Data were expressed as mean ± SEM. Statistical comparisons were made using a two-tailed Student’s t-test. Normalized (to respective control values) - relationships for current measured at the end of depolarizing steps (c) and tail currents (d) in the control and the presence of 1 μM, 5 μM, and 10 μM GA. Data are expressed as mean ± SEM; . Statistical comparisons were made using a two-tailed Student’s t-test (, ).
