Fig. 9.

CRF₂-dependent ERK1/2 activation in rat primary esophageal cells. Primary cultures of rat esophageal mucosal cells (1×10⁶ cells/well) were treated with Ucn 2 in the absence and presence of 1μm astressin₂-B or with CRF₁-selective agonist cortagine at the indicated concentrations (10⁻¹⁰ to 10⁻⁶ m) for 5 min. Cells were then harvested and extracted cellular proteins were analyzed by immunoblotting using anti-phospho-ERK1/2 and anti-ERK/1/2 antibodies to detect activated pERK1/2 and total ERK, respectively. Representative images were shown to demonstrate CRF₂-dependent ERK1/2 phosphorylation (A–C). Bar graphs represent the percent of maximal change of pERK1/2 stimulated by agoni6sts (100 nm) with or without astressin₂-B over the vehicle-control value. Signals were measured using Kodak 1D image analysis software and data represent mean ± se of two experiments (*, P < 0.05; **, P < 0.001 vs. vehicle control). Veh, Vehicle.