Figure 5. Angiotensin II reduces functional K_V1.5 channel activity in pressurized arteries.

A, representative diameter traces for vasoconstriction stimulated by Psora‐4 (100 nm) or 4‐aminopyridine (4‐AP, 1 mm) at an intravascular pressure of 80 mmHg for arteries maintained for 2 h in 30 mm K⁺ alone (control) or plus Ang II (100 nm) or plus Ang II with BIM (10 μm). Initial arterial diameters before application of Psora‐4 or 4‐AP were normalized. B, mean data illustrating vasoconstriction stimulated by Psora‐4 or 4‐AP. n = 6 for each. Mean passive diameters were similar for arteries used in each data set (P > 0.05 for each, e.g. mean passive diameter for control arteries was 231.6 ± 4.7 μm, for Ang II‐treated arteries 228.0 ± 4.1 μm, and for arteries treated with Ang II and BIM 232.8 ± 4.8 μm). ^* P < 0.05 vs. control. C, mean data for vasoconstrictive response to 60 mm K⁺ PSS at 80 mmHg intravascular pressure. n = 6 for each.