Fig. 7
Five-day exposure of sensory neuronal cultures to PGE2 does not produce heterologous desensitization. Each column represents the mean ± SEM of the treatment-stimulated PKA activity normalized to total PKA activity in cultures exposed to vehicle for 5 days or PGE2 (1 μM) for 5 days as indicated. a Cultures were washed and then re-exposed for 10 min to vehicle (open columns) or CTX (1.5 μg/ml) overnight (shaded columns). b Cultures were washed and then re-exposed for 10 min to vehicle (open columns) or 1 μM forskolin for 20 min (shaded columns). c Cultures were washed and then re-exposed for 10 min to vehicle (open columns) or 1 μM cPGI2 (shaded columns) for 20 min. An asterisk indicates statistically significant difference from vehicle using one-way ANOVA followed by Bonferroni’s post hoc test. d The left panel represents PKA activity from cells exposed to vehicle for 12 h in the absence or presence of 10 μM H-89 or 1 μM BIM-I as indicated, while the right panel represents PKA activity from cells exposed to PGE2 (1 μM) for 12 h in the absence or presence of 10 μM H-89 or 1 μM BIM-I as indicated. After washing, the cells were re-exposed to vehicle (open columns) or 1 μM PGE2 (shaded and hatched columns) for 10 min. Asterisks indicate statistically significant differences in cells acutely exposed to vehicle versus cells exposed to PGE2. Crosses represent statistically significant differences in cells preexposed for 12 h to vehicle versus those exposed for 12 h to PGE2. Statistical analysis was performed using one-way ANOVA followed by Bonferroni’s post hoc test