Fig. 2.
Effect of the constriction length (i.e., the duration of increased shear stress) on ATP release in constrictions with fixed width (wc = 20 μm). (A) The photon emission rate versus elapsed time (measured from the constriction entrance) for six different channels with different lengths (ℓc = 100–3,200 μm). Arrows indicate the approximate time at which the photon rate begins to increase. The error bars are reported as the standard error of the mean (n = 5). (B) The delay time observed from A versus the duration of the increased shear stress (τc) for five different channels with fixed widths (wc = 20 μm) but different lengths (ℓc = 200–3,200 μm). The error bars are reported as uncertainty bars between data points. (C) The average released ATP concentration versus the duration of the increased shear stress (τc). The error bars are reported as the standard error of the mean (n = 5). All reported times are estimates based on the average flow rate, cf. Eq. 1.