Dynamics of the Ca<sup>2+</sup> depletion waves.

<p><b>A)</b> Heat map generated from the time-lapse fluorescence microscopy movie (10 s intervals) of rat SMCs treated with ET-1 (100 nM) in nominally free extracellular Ca<sup>2+</sup>, showing that the SR depletion wave expands in a near circular fashion in both directions of the scan line (dotted white line). <b>B)</b> Average travel distance and velocity of ET-1-induced depletion wave <i>vs.</i> time. As the distance from the point of origin increases, the wave velocity decreases asymptotically to zero. <b>C)</b> Average values for <i>R/R<sub>0</sub></i> and [Ca<sup>2+</sup>]<sub>SR</sub> at the rim of the depletion wave also decreases as the wave expands over time (ROI = 5, n = 5 independent experiments, mean ± SEM, <i>P</i><0.005).</p>