Fig. 1.

Endothelial whole cell voltage-clamp recording. A: voltage-clamp recording protocol (top) and a representative trace (bottom). Cells were held at −60 mV and a voltage ramp of −80 to +50 mV (200 ms), followed by voltage steps to +20 mV (200 ms) and back to −60 mV (50 ms) were delivered. B: cell membrane capacitance (Cm) plotted against time of recording (top). Time 0 indicates whole cell formation. Capacitance was measured from the hyperpolarizing steps from +20 to −60 mV. Whole cell current density plotted against the time of recording (bottom). Current density was calculated from the steady-state currents recordings at +20 mV, normalized to the membrane capacitance. Numbers on the plot correspond to the representative voltage-ramp current density traces in C. C: representative whole cell current density elicited by −80 to +50 mV voltage-ramp. D: IK1 and SK3 current densities isolated from digital subtraction of the traces in C. E: normalized contribution of IK1 and SK3 currents to the whole cell currents.