K⁺channel inhibition, calcium signaling, and vasomotor tone in canine pulmonary artery smooth muscle

Canine pulmonary artery smooth muscle cells (PASMCs) and isolated pulmonary arterial rings

Inhibition of voltage-gated K(+) channels with 4-aminopyridine (4-AP), inhibition of Ca(2+)-activated K(+) channels with charybdotoxin, inhibition of ATP-sensitive K(+) channels with glibenclamide, or activation with lemakalim

Baseline/control conditions

Intracellular free Ca(2+) concentration ([Ca(2+)](i)), alpha-adrenoreceptor-mediated Ca(2+) signaling, capacitative Ca(2+) entry, and vasomotor tonesurrogate