Figure 3.

Antagonism of PGE₂ concentration–effect (E/[A]) curves in PSV by GW627368X. Panel a: Mean PGE2 E/[A] curves in the presence of vehicle and GW627368X 1, 3, 10, 30, 100, 300 nM, 1, 3, and 10 μM (n=3). Tissues were incubated with antagonist for 60 min prior to exposure to PGE₂ as described in Methods. Panel b: Antagonist competition analysis using nonlinear regression as described in Methods. An additional line (shown in dots and dashes) illustrates the antagonist resistant phase of the data (100 nM–10 μM GW627368X).