Cultured goblet cells were preincubated with the PLC inhibitor U73122 and its negative control U73343, both at 10−6 M, for 15 min (A and B), 2-APB (10−6 and 10−5 M) for 10 min (C and D), thapsagargin for 15 min (E and F) or Ro 31–8220 for 10 min (G and H). [Ca2+]i over time is shown in A, C, E, and G. Change in peak [Ca2+]i is shown in B, D, F, and H. Data are mean ± SEM from 3 (A and B), 7 (C and D), 6 (E and F) and 6 (G and H) independent experiments. * indicates significant difference from basal; # indicates significance from RvE1 alone.