FIGURE 16.
Large-conductance Ca2+-activated K+ (KCa) currents in pulmonary arterial smooth muscle cells (PASMCs). A: representative single-channel K+ currents in cell-attached membrane patch elicited by depolarizing the patch to a series of test potentials in a PASMC bathed in physiological salt solution (left). The current-voltage (I-V) relationship curve (right), which shifts to the right because of the membrane potential (−43 mV), shows a slope conductance (g) of 249 pS. B, top: representative single-channel KCa currents in a cell-attached membrane patch of PASMC before (Control), during (NO), and after (Recovery) extracellular application of the nitric oxide (NO) donor S-nitroso-N-acetylpenicillamine. Bottom: the steady-state open probability (NPopen) of the currents.