IP3R2-deficiency leads to reduced apical Ca²⁺ signals

<p>(A) From left to right: Bright field view of an acinus, with a single acinar cell labeled at the apical (Ap) and basolateral (Bl) regions of interest. Fluorescent images of acini loaded with the Ca<sup>2+</sup> indicator fluo-4 at baseline (1), shortly after stimulation with 1 uM carbachol (2), and subsequent images showing propagation of the Ca<sup>2+</sup> wave from the apical to the basolateral region (3,4). (B) Each paneled image (1–4) also corresponds to a frame along a representative tracing of change in fluorescence over time for each region of interest. (C) Comparisons of the amplitude, latency period, and Ca<sup>2+</sup> wave speed between WT and IP3R2<sup>−/−</sup> cells (n = 25–40 cells in each group). The time from the administration of carbachol to the first Ca<sup>2+</sup> rise in the apical region is the latency period. *, P<0.05 relative to WT.</p