DOR agonist induced phosphorylation of the MAP-kinase, ERK2, is increased by (1DMe)NPYF. A. Total cell lysates (10 μg protein per lane) were detected with phosphoERK2 and total ERK2 specific antibodies. The equal loading of samples was controlled with anti-tubulin antibody. The cells were treated with 100 nM DPDPE alone (left panel), with 100 nM DPDPE together with 100 nM (1DMe)NPYF (middle panel) or with 100 nM (1DMe)NPYF (right panel) for 5, 10 or 30 min. (1DMe)NPYF alone could not induce the phosphorylation of ERK2 above the basal level. The data shown are representative figures of five independent experiments. B. The band intensities of phosphoERK2 were quantified and they are presented as relative band intensities with respect to the total ERK2. The dashed bars represent the cells treated with 100 nM DPDPE alone and the solid bars cells treated with 100 nM DPDPE and 100 nM (1DMe)NPYF. The statistical significance between time-points and treatments was analyzed with two-way Anova with Bonferroni's post-test, n = 5. Both of the treatments significantly induced the phosphorylation of the ERK2 above the basal level at all time-points (***p < 0.001). The difference between treatments was significant at the first time-point tested (††p < 0.01).