Fig. 5.

Effects of pannexin1 inhibitors on sustained ATP release. a Luminescence was measured from dishes with HTC cells in response to hypotonic solution (30% dilution, closed bar) under control conditions (n = 4 dishes, open circles). In some experiments, cells were pretreated with 20 microM CBX for 5 min (open bar) before the exposure to hypotonic solution (n = 6 dishes, closed circles). Note that CBX did not inhibit ATP release. b Luminescence change evoked by hypotonic solution was measured as described in Materials and methods from dishes with HTC cells pretreated with pannexin1 inhibitors for 5 min before the exposure to hypotonic solution. The concentration of inhibitors was 1 mM for probenecid, and 0.1 mM for FFA. CBX was used at 20 or 100 microM. Because FFA decreased the sensitivity of luciferin–luciferase to ATP by ~60%, luminescence measured in the presence of FFA was multiplied by 2.5. The number of dishes ranged from 4 to 19