Figure 12.
Whole-cell voltage-gated K+ (Kv) currents (IK(V)) in human pulmonary artery smooth muscle cells (PASMC). (a–d) Four different types of Kv currents were elicited by step depolarizations from a holding potential of −70 mV to test potentials between -80 mV and +80 mV in 20 mV increments. Representative families of currents (left panels), enlarged trace segments showing steady-state activation (middle, top panels) and inactivation (middle, bottom panels) and I-V curves are presented for each type of current. (e) Activation (top) and inactivation (bottom) time constants are plotted as a function of cell number. The majority of currents activated rapidly (within 1-4 ms). The range of inactivation constants is more varied, reflecting the different current types