Fig. 2

Inhibition of Ca²⁺ sparks with ryanodine increases the global [Ca²⁺]_i and constricts the SMA. a Representative recordings of [Ca²⁺]_i changes from single smooth muscle cells from a pressurized (40 cmH₂O) SMA in response to 10 μM ryanodine (Ryn). b Average of normalized traces of [Ca²⁺]_i changes at 40 cmH₂O (48 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 (average 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