Fig. 4

Inhibition of BK channels in the presence of high K⁺ does not increase the global [Ca²⁺]_i or constrict the SMA. a Representative recordings of [Ca²⁺]_i changes from single smooth muscle cells from a pressurized (40 cmH₂O) SMA in the presence of PSS containing 30 mM K⁺ and 100 nM Ibtx. b Average of normalized traces of [Ca²⁺]_i changes in the presence of PSS containing 30 mM K⁺ and Ibtx (36 cells). Traces in a and b were normalized as described in Methods. c Average trace of corresponding changes in vascular diameter (6 arteries). Diameter changes were normalized to the average of values recorded between 30 – 60 s (value indicated by ‘a’ was set to 1). [Ca²⁺]_i and diameter data were simultaneously acquired at 1 s intervals, however, for clarity, error bars (sem) are plotted only every 10 s