Figure 1. Effects of sex-steroid hormones E2, progesterone, and testosterone on cardiac ion channels.

(A) Dose-dependence curves are shown for experimental (left traces) and simulated (right traces) inhibition of I_Kr current by E2. The simulated I_Kr tail currents (right) compared to experimentally measured I_Kr (left) at −40 mV following depolarization to a test potential = +20 mV in the absence (control) or presence of E2 (1 and 10 nM). (B) I_Ks was experimentally recorded at a test potential of +50 mV from a holding potential of −40 mV with 0 nM and 100 nM progesterone (top traces). Simulated (lower races) I_Ks are shown in the presence of 0 nM (control case), 2.5 nM (follicular phase), 40.6 nM (luteal phase) and 100 nM progesterone during a voltage pulse from −40 mV to +50 mV. (C) I_Ks (left panels) were elicited by 3.5-s test pulses to +50 mV from a holding potential of −40 mV (experiment — top traces and simulation — lower traces) in the absence and presence of testosterone (10 nM and 300 nM). The effect on I_Ca,L (right panels) from experimental data (top traces) and simulated results (lower traces) during a voltage step from −40 mV to 0 mV under control condition (0 nM), 10 nM and 300 nM testosterone.