Figure 8.

Bitter stimulation activates a PLC mediated Ca²⁺ release from intracellular store in tracheal epithelial cells. (a) Representative calcium transients recorded from a cell repeatedly stimulated with 5 mM denatonium in control Ringer’s solution or in the absence of extracellular Ca²⁺. The same experiments were repeated after application of (b) 10 µM PLC inhibitor U73122, or (c) 10 µM of the inactive analogue U73433 Right panels: heat maps from several cells showing normalized changes in fluorescence intensity following stimulations with denatonium in the conditions indicated in the corresponding left panels. All data were normalized to the peak value obtained from the first stimulation (data from 1–4 slices; **P < 0.01 U-test).