Figure 1.

Ion channel expression in PMVECs and PAECs. Western blot analysis was performed to examine TRPV4, BK, IK, and SK3 channels and β-actin expression in heterologous expression systems, as well as in PMVECs and PAECs. A, Representative Western blot analysis of cell lysates of nontransfected (lane 1) and transfected (lane 2) HEK or COS-7 cells, used as negative and positive controls, respectively, PMVECs (lane 3, MV), and PAECs (lane 4, PA). B, After densitometry, values for TRPV4, BK, IK, and SK3 were normalized to β-actin, then expression in MV was reported relative to that for PA. A ratio of 1, shown as the dotted line, would indicate equal protein expression in PMVECs and PAECs. BK, IK, SK3: large-, intermediate-, and small-conductance (subtype 3) K_Ca (Ca²⁺-activated potassium) channels, respectively; COS-7: monkey kidney fibroblast; HEK: human embryonic kidney; PAECs: pulmonary arterial endothelial cells; PMVECs: pulmonary microvascular endothelial cells; TRPV4: transient receptor potential vanilloid 4.