Fig. 5. FRAP analysis of GFP-labeled apical actin filaments in lacrimal acini. (A) Representative scans of apical actin intensity before [Pre-(–1s)], during [Bleaching (0 seconds)] and after [Post-(100 seconds)] photobleaching in unstimulated (CON) and CCH-stimulated (100 µM, 10 minutes) lacrimal acini. The circular region is the ROI and bar, 5 µm. (B) Typical plots of fluorescence over initial fluorescence (F/F_i) for resting and CCH-stimulated (100 µM, 10 minutes) acini. Fractional fluorescence was calculated by F–F₀/F_i–F₀. (C) M_f values for apical actin filaments in resting and stimulated acini analyzed after the indicated exposures to CCH. (D) Turnover times (t) for apical actin filaments in resting and stimulated acini analyzed after the indicated ranges of exposure to CCH as described in Materials and Methods. Results from (C) and (D) were obtained from 3-7 dishes in each preparation from n=5 preparations; *P0.05.