Figure 2.

Inhibitory effects of EPA on I_Na,α of hH1_α channels expressed in HEK293t cells. (A) Whole-cell voltage-clamp traces from HEK293t cells expressing hH1_α are superimposed. They were elicited by 10-ms test pulses from −90 mV to 55 mV with 5-mV increments at 0.2 Hz for control, 5 μM EPA and washout. The cell was held at −80 mV and hyperpolarized to −160 mV for 200 ms before a test pulse. (B) EPA suppressed I_Na,α is concentration-dependent with an IC₅₀ of 0.51 ± 0.06 μM. I_Na,α was elicited by single voltage pulses from −120 to −30 mV. The sigmoidal curve is fit by y = {(A₁ − A₂)/[1 + (x/x₀)^p]}, origin 4.1, Microcal Software. Each value represents 6–12 individual preparations exposed to different concentrations of EPA. (C) Voltage-dependent suppression by EPA (5 μM) of I_Na,α in HEK293t cells expressing hH1_α. The cells were held at −80 mV and hyperpolarized to −90, −120, and −150 mV for 200 ms before a test pulse to −30 mV.